com.fasterxml.jackson.core

Class JsonGenerator

    • Field Detail

      • _cfgPrettyPrinter

        protected PrettyPrinter _cfgPrettyPrinter
        Object that handles pretty-printing (usually additional white space to make results more human-readable) during output. If null, no pretty-printing is done.

    • Constructor Detail

      • JsonGenerator

        protected JsonGenerator()

    • Method Detail

      • setCodec

        public abstract JsonGenerator setCodec(ObjectCodec oc)
        Method that can be called to set or reset the object to use for writing Java objects as JsonContent (using method writeObject(java.lang.Object)).
        Parameters:
        oc - Codec to assign, if any; null if none
        Returns:
        This generator, to allow call chaining

      • getCodec

        public abstract ObjectCodec getCodec()
        Method for accessing the object used for writing Java object as JSON content (using method writeObject(java.lang.Object)).
        Returns:
        Codec assigned to this generator, if any; null if none

      • version

        public abstract Version version()
        Accessor for finding out version of the bundle that provided this generator instance.
        Specified by:
        version in interface Versioned
        Returns:
        Version of this generator (derived from version declared for jackson-core jar that contains the class

      • getOutputContext

        public abstract JsonStreamContext getOutputContext()
        Accessor for context object that provides information about low-level logical position withing output token stream.
        Returns:
        Stream output context (JsonStreamContext) associated with this generator

      • getOutputTarget

        public Object getOutputTarget()
        Method that can be used to get access to object that is used as target for generated output; this is usually either OutputStream or Writer, depending on what generator was constructed with. Note that returned value may be null in some cases; including case where implementation does not want to exposed raw source to caller. In cases where output has been decorated, object returned here is the decorated version; this allows some level of interaction between users of generator and decorator object.

        In general use of this accessor should be considered as "last effort", i.e. only used if no other mechanism is applicable.

        Returns:
        Output target this generator was configured with

      • getCurrentValue

        public Object getCurrentValue()
        Helper method, usually equivalent to: getOutputContext().getCurrentValue();

        Note that "current value" is NOT populated (or used) by Streaming parser or generators; it is only used by higher-level data-binding functionality. The reason it is included here is that it can be stored and accessed hierarchically, and gets passed through data-binding.

        Returns:
        "Current value" associated with the current context (state) of this generator
        Since:
        2.5

      • setCurrentValue

        public void setCurrentValue(Object v)
        Helper method, usually equivalent to: getOutputContext().setCurrentValue(v);
        Parameters:
        v - Current value to assign for the current context of this generator
        Since:
        2.5

      • configure

        public final JsonGenerator configure(JsonGenerator.Feature f,
                                     boolean state)
        Method for enabling or disabling specified feature: check JsonGenerator.Feature for list of available features.
        Parameters:
        f - Feature to enable or disable
        state - Whether to enable (true) or disable (false) feature
        Returns:
        This generator, to allow call chaining

      • isEnabled

        public abstract boolean isEnabled(JsonGenerator.Feature f)
        Method for checking whether given feature is enabled. Check JsonGenerator.Feature for list of available features.
        Parameters:
        f - Feature to check
        Returns:
        True if specified feature is enabled; false if not

      • isEnabled

        public boolean isEnabled(StreamWriteFeature f)
        Method for checking whether given feature is enabled. Check JsonGenerator.Feature for list of available features.
        Parameters:
        f - Feature to check
        Returns:
        True if specified feature is enabled; false if not
        Since:
        2.10

      • getFeatureMask

        public abstract int getFeatureMask()
        Bulk access method for getting state of all standard (non-dataformat-specific) JsonGenerator.Features.
        Returns:
        Bit mask that defines current states of all standard JsonGenerator.Features.
        Since:
        2.3

      • overrideStdFeatures

        public JsonGenerator overrideStdFeatures(int values,
                                         int mask)
        Bulk set method for (re)setting states of features specified by mask. Functionally equivalent to int oldState = getFeatureMask(); int newState = (oldState & ~mask) | (values & mask); setFeatureMask(newState); but preferred as this lets caller more efficiently specify actual changes made.
        Parameters:
        values - Bit mask of set/clear state for features to change
        mask - Bit mask of features to change
        Returns:
        This generator, to allow call chaining
        Since:
        2.6

      • getFormatFeatures

        public int getFormatFeatures()
        Bulk access method for getting state of all FormatFeatures, format-specific on/off configuration settings.
        Returns:
        Bit mask that defines current states of all standard FormatFeatures.
        Since:
        2.6

      • overrideFormatFeatures

        public JsonGenerator overrideFormatFeatures(int values,
                                            int mask)
        Bulk set method for (re)setting states of FormatFeatures, by specifying values (set / clear) along with a mask, to determine which features to change, if any.

        Default implementation will simply throw an exception to indicate that the generator implementation does not support any FormatFeatures.

        Parameters:
        values - Bit mask of set/clear state for features to change
        mask - Bit mask of features to change
        Returns:
        This generator, to allow call chaining
        Since:
        2.6

      • setSchema

        public void setSchema(FormatSchema schema)
        Method to call to make this generator use specified schema. Method must be called before generating any content, right after instance has been created. Note that not all generators support schemas; and those that do usually only accept specific types of schemas: ones defined for data format this generator produces.

        If generator does not support specified schema, UnsupportedOperationException is thrown.

        Parameters:
        schema - Schema to use
        Throws:
        UnsupportedOperationException - if generator does not support schema

      • getSchema

        public FormatSchema getSchema()
        Method for accessing Schema that this generator uses, if any; null if none. Default implementation returns null.
        Returns:
        Schema in use by this generator, if any; null if none

      • setPrettyPrinter

        public JsonGenerator setPrettyPrinter(PrettyPrinter pp)
        Method for setting a custom pretty printer, which is usually used to add indentation for improved human readability. By default, generator does not do pretty printing.

        To use the default pretty printer that comes with core Jackson distribution, call useDefaultPrettyPrinter() instead.

        Parameters:
        pp - PrettyPrinter to assign, if any; null if none
        Returns:
        This generator, to allow call chaining

      • getPrettyPrinter

        public PrettyPrinter getPrettyPrinter()
        Accessor for checking whether this generator has a configured PrettyPrinter; returns it if so, null if none configured.
        Returns:
        PrettyPrinter configured for this generator, if any; null if none

      • useDefaultPrettyPrinter

        public abstract JsonGenerator useDefaultPrettyPrinter()
        Convenience method for enabling pretty-printing using the default pretty printer (DefaultPrettyPrinter).
        Returns:
        This generator, to allow call chaining

      • setHighestNonEscapedChar

        public JsonGenerator setHighestNonEscapedChar(int charCode)
        Method that can be called to request that generator escapes all character codes above specified code point (if positive value); or, to not escape any characters except for ones that must be escaped for the data format (if -1). To force escaping of all non-ASCII characters, for example, this method would be called with value of 127.

        Note that generators are NOT required to support setting of value higher than 127, because there are other ways to affect quoting (or lack thereof) of character codes between 0 and 127. Not all generators support concept of escaping, either; if so, calling this method will have no effect.

        Default implementation does nothing; sub-classes need to redefine it according to rules of supported data format.

        Parameters:
        charCode - Either -1 to indicate that no additional escaping is to be done; or highest code point not to escape (meaning higher ones will be), if positive value.
        Returns:
        This generator, to allow call chaining

      • getHighestEscapedChar

        public int getHighestEscapedChar()
        Accessor method for testing what is the highest unescaped character configured for this generator. This may be either positive value (when escaping configuration has been set and is in effect), or 0 to indicate that no additional escaping is in effect. Some generators may not support additional escaping: for example, generators for binary formats that do not use escaping should simply return 0.
        Returns:
        Currently active limitation for highest non-escaped character, if defined; or 0 to indicate no additional escaping is performed.

      • getCharacterEscapes

        public CharacterEscapes getCharacterEscapes()
        Method for accessing custom escapes factory uses for JsonGenerators it creates.
        Returns:
        CharacterEscapes configured for this generator, if any; null if none

      • setCharacterEscapes

        public JsonGenerator setCharacterEscapes(CharacterEscapes esc)
        Method for defining custom escapes factory uses for JsonGenerators it creates.

        Default implementation does nothing and simply returns this instance.

        Parameters:
        esc - CharacterEscapes to configure this generator to use, if any; null if none
        Returns:
        This generator, to allow call chaining

      • setRootValueSeparator

        public JsonGenerator setRootValueSeparator(SerializableString sep)
        Method that allows overriding String used for separating root-level JSON values (default is single space character)

        Default implementation throws UnsupportedOperationException.

        Parameters:
        sep - Separator to use, if any; null means that no separator is automatically added
        Returns:
        This generator, to allow call chaining

      • getOutputBuffered

        public int getOutputBuffered()
        Method for verifying amount of content that is buffered by generator but not yet flushed to the underlying target (stream, writer), in units (byte, char) that the generator implementation uses for buffering; or -1 if this information is not available. Unit used is often the same as the unit of underlying target (that is, `byte` for OutputStream, `char` for Writer), but may differ if buffering is done before encoding. Default JSON-backed implementations do use matching units.

        Note: non-JSON implementations will be retrofitted for 2.6 and beyond; please report if you see -1 (missing override)

        Returns:
        Amount of content buffered in internal units, if amount known and accessible; -1 if not accessible.
        Since:
        2.6

      • canUseSchema

        public boolean canUseSchema(FormatSchema schema)
        Method that can be used to verify that given schema can be used with this generator (using setSchema(com.fasterxml.jackson.core.FormatSchema)).
        Parameters:
        schema - Schema to check
        Returns:
        True if this generator can use given schema; false if not

      • canWriteObjectId

        public boolean canWriteObjectId()
        Introspection method that may be called to see if the underlying data format supports some kind of Object Ids natively (many do not; for example, JSON doesn't). This method must be called prior to calling writeObjectId(java.lang.Object) or writeObjectRef(java.lang.Object).

        Default implementation returns false; overridden by data formats that do support native Object Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it can not use native object ids.

        Returns:
        True if this generator is capable of writing "native" Object Ids (which is typically determined by capabilities of the underlying format), false if not
        Since:
        2.3

      • canWriteTypeId

        public boolean canWriteTypeId()
        Introspection method that may be called to see if the underlying data format supports some kind of Type Ids natively (many do not; for example, JSON doesn't). This method must be called prior to calling writeTypeId(java.lang.Object).

        Default implementation returns false; overridden by data formats that do support native Type Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it can not use native type ids.

        Returns:
        True if this generator is capable of writing "native" Type Ids (which is typically determined by capabilities of the underlying format), false if not
        Since:
        2.3

      • canWriteBinaryNatively

        public boolean canWriteBinaryNatively()
        Introspection method that may be called to see if the underlying data format supports "native" binary data; that is, an efficient output of binary content without encoding.

        Default implementation returns false; overridden by data formats that do support native binary content.

        Returns:
        True if this generator is capable of writing "raw" Binary Content (this is typically determined by capabilities of the underlying format); false if not
        Since:
        2.3

      • canOmitFields

        public boolean canOmitFields()
        Introspection method to call to check whether it is ok to omit writing of Object fields or not. Most formats do allow omission, but certain positional formats (such as CSV) require output of placeholders, even if no real values are to be emitted.
        Returns:
        True if this generator is allowed to only write values of some Object fields and omit the rest; false if not
        Since:
        2.3

      • canWriteFormattedNumbers

        public boolean canWriteFormattedNumbers()
        Introspection method to call to check whether it is possible to write numbers using writeNumber(java.lang.String) using possible custom format, or not. Typically textual formats allow this (and JSON specifically does), whereas binary formats do not allow this (except by writing them as Strings). Usual reason for calling this method is to check whether custom formatting of numbers may be applied by higher-level code (databinding) or not.
        Returns:
        True if this generator is capable of writing "formatted" numbers (and if so, need to be passed using writeNumber(String), that is, passed as String); false if not
        Since:
        2.8

      • getWriteCapabilities

        public JacksonFeatureSet<StreamWriteCapability> getWriteCapabilities()
        Accessor for getting metadata on capabilities of this generator, based on underlying data format being read (directly or indirectly).
        Returns:
        Set of write capabilities for content written using this generator
        Since:
        2.12

      • writeStartArray

        public abstract void writeStartArray()
                              throws IOException
        Method for writing starting marker of a Array value (for JSON this is character '['; plus possible white space decoration if pretty-printing is enabled).

        Array values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.

        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeStartArray

        @Deprecated
public void writeStartArray(int size)
                                 throws IOException
        Deprecated. Since 2.12 Use writeStartArray(Object, int) instead
        Method for writing start marker of an Array value, similar to writeStartArray(), but also specifying how many elements will be written for the array before calling writeEndArray().

        Default implementation simply calls writeStartArray().

        Parameters:
        size - Number of elements this array will have: actual number of values written (before matching call to writeEndArray() MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.4

      • writeStartArray

        public void writeStartArray(Object forValue)
                     throws IOException
        Method for writing start marker of an Array value, similar to writeStartArray(), but also specifying the "current value" to assign to the new Array context being created.
        Parameters:
        forValue - "Current value" to assign for the Array context being created
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.10

      • writeStartArray

        public void writeStartArray(Object forValue,
                            int size)
                     throws IOException
        Method for writing start marker of an Array value, similar to writeStartArray(), but also specifying the "current value" to assign to the new Array context being created as well as how many elements will be written for the array before calling writeEndArray().
        Parameters:
        forValue - "Current value" to assign for the Array context being created
        size - Number of elements this Array will have: actual number of values written (before matching call to writeEndArray() MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.10

      • writeEndArray

        public abstract void writeEndArray()
                            throws IOException
        Method for writing closing marker of a JSON Array value (character ']'; plus possible white space decoration if pretty-printing is enabled).

        Marker can be written if the innermost structured type is Array.

        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeStartObject

        public abstract void writeStartObject()
                               throws IOException
        Method for writing starting marker of an Object value (character '{'; plus possible white space decoration if pretty-printing is enabled).

        Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.

        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeStartObject

        public void writeStartObject(Object forValue)
                      throws IOException
        Method for writing starting marker of an Object value to represent the given Java Object value. Argument is offered as metadata, but more importantly it should be assigned as the "current value" for the Object content that gets constructed and initialized.

        Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.

        Parameters:
        forValue - "Current value" to assign for the Object context being created
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeStartObject

        public void writeStartObject(Object forValue,
                             int size)
                      throws IOException
        Method for writing starting marker of an Object value to represent the given Java Object value. Argument is offered as metadata, but more importantly it should be assigned as the "current value" for the Object content that gets constructed and initialized. In addition, caller knows number of key/value pairs ("properties") that will get written for the Object value: this is relevant for some format backends (but not, as an example, for JSON).

        Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.

        Parameters:
        forValue - "Current value" to assign for the Object context being created
        size - Number of key/value pairs this Object will have: actual number of entries written (before matching call to writeEndObject() MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.10

      • writeEndObject

        public abstract void writeEndObject()
                             throws IOException
        Method for writing closing marker of an Object value (character '}'; plus possible white space decoration if pretty-printing is enabled).

        Marker can be written if the innermost structured type is Object, and the last written event was either a complete value, or START-OBJECT marker (see JSON specification for more details).

        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeFieldName

        public abstract void writeFieldName(String name)
                             throws IOException
        Method for writing a field name (JSON String surrounded by double quotes: syntactically identical to a JSON String value), possibly decorated by white space if pretty-printing is enabled.

        Field names can only be written in Object context (check out JSON specification for details), when field name is expected (field names alternate with values).

        Parameters:
        name - Field name to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeFieldName

        public abstract void writeFieldName(SerializableString name)
                             throws IOException
        Method similar to writeFieldName(String), main difference being that it may perform better as some of processing (such as quoting of certain characters, or encoding into external encoding if supported by generator) can be done just once and reused for later calls.

        Default implementation simple uses unprocessed name container in serialized String; implementations are strongly encouraged to make use of more efficient methods argument object has.

        Parameters:
        name - Field name to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeFieldId

        public void writeFieldId(long id)
                  throws IOException
        Alternative to writeFieldName(String) that may be used in cases where property key is of numeric type; either where underlying format supports such notion (some binary formats do, unlike JSON), or for convenient conversion into String presentation. Default implementation will simply convert id into String and call writeFieldName(String).
        Parameters:
        id - Field id to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeArray

        public void writeArray(int[] array,
                       int offset,
                       int length)
                throws IOException
        Value write method that can be called to write a single array (sequence of JsonToken.START_ARRAY, zero or more JsonToken.VALUE_NUMBER_INT, JsonToken.END_ARRAY)
        Parameters:
        array - Array that contains values to write
        offset - Offset of the first element to write, within array
        length - Number of elements in array to write, from `offset` to `offset + len - 1`
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeArray

        public void writeArray(long[] array,
                       int offset,
                       int length)
                throws IOException
        Value write method that can be called to write a single array (sequence of JsonToken.START_ARRAY, zero or more JsonToken.VALUE_NUMBER_INT, JsonToken.END_ARRAY)
        Parameters:
        array - Array that contains values to write
        offset - Offset of the first element to write, within array
        length - Number of elements in array to write, from `offset` to `offset + len - 1`
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeArray

        public void writeArray(double[] array,
                       int offset,
                       int length)
                throws IOException
        Value write method that can be called to write a single array (sequence of JsonToken.START_ARRAY, zero or more JsonToken.VALUE_NUMBER_FLOAT, JsonToken.END_ARRAY)
        Parameters:
        array - Array that contains values to write
        offset - Offset of the first element to write, within array
        length - Number of elements in array to write, from `offset` to `offset + len - 1`
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeArray

        public void writeArray(String[] array,
                       int offset,
                       int length)
                throws IOException
        Value write method that can be called to write a single array (sequence of JsonToken.START_ARRAY, zero or more JsonToken.VALUE_STRING, JsonToken.END_ARRAY)
        Parameters:
        array - Array that contains values to write
        offset - Offset of the first element to write, within array
        length - Number of elements in array to write, from `offset` to `offset + len - 1`
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.11

      • writeString

        public abstract void writeString(String text)
                          throws IOException
        Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification.
        Parameters:
        text - Text value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeString

        public void writeString(Reader reader,
                        int len)
                 throws IOException
        Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification. If len is < 0, then write all contents of the reader. Otherwise, write only len characters.

        Note: actual length of content available may exceed len but can not be less than it: if not enough content available, a JsonGenerationException will be thrown.

        Parameters:
        reader - Reader to use for reading Text value to write
        len - Maximum Length of Text value to read (in chars, non-negative) if known; -1 to indicate "read and write it all"
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer; or if length (len) is specified but reader does not provide enough content
        Since:
        2.9

      • writeString

        public abstract void writeString(char[] buffer,
                                 int offset,
                                 int len)
                          throws IOException
        Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification.
        Parameters:
        buffer - Buffer that contains String value to write
        offset - Offset in buffer of the first character of String value to write
        len - Length of the String value (in characters) to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeString

        public abstract void writeString(SerializableString text)
                          throws IOException
        Method similar to writeString(String), but that takes SerializableString which can make this potentially more efficient to call as generator may be able to reuse quoted and/or encoded representation.

        Default implementation just calls writeString(String); sub-classes should override it with more efficient implementation if possible.

        Parameters:
        text - Pre-encoded String value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRawUTF8String

        public abstract void writeRawUTF8String(byte[] buffer,
                                        int offset,
                                        int len)
                                 throws IOException
        Method similar to writeString(String) but that takes as its input a UTF-8 encoded String that is to be output as-is, without additional escaping (type of which depends on data format; backslashes for JSON). However, quoting that data format requires (like double-quotes for JSON) will be added around the value if and as necessary.

        Note that some backends may choose not to support this method: for example, if underlying destination is a Writer using this method would require UTF-8 decoding. If so, implementation may instead choose to throw a UnsupportedOperationException due to ineffectiveness of having to decode input.

        Parameters:
        buffer - Buffer that contains String value to write
        offset - Offset in buffer of the first byte of String value to write
        len - Length of the String value (in characters) to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeUTF8String

        public abstract void writeUTF8String(byte[] buffer,
                                     int offset,
                                     int len)
                              throws IOException
        Method similar to writeString(String) but that takes as its input a UTF-8 encoded String which has not been escaped using whatever escaping scheme data format requires (for JSON that is backslash-escaping for control characters and double-quotes; for other formats something else). This means that textual JSON backends need to check if value needs JSON escaping, but otherwise can just be copied as is to output. Also, quoting that data format requires (like double-quotes for JSON) will be added around the value if and as necessary.

        Note that some backends may choose not to support this method: for example, if underlying destination is a Writer using this method would require UTF-8 decoding. In this case generator implementation may instead choose to throw a UnsupportedOperationException due to ineffectiveness of having to decode input.

        Parameters:
        buffer - Buffer that contains String value to write
        offset - Offset in buffer of the first byte of String value to write
        len - Length of the String value (in characters) to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRaw

        public abstract void writeRaw(String text)
                       throws IOException
        Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, use writeRawValue(String) instead.

        Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw UnsupportedOperationException.

        Parameters:
        text - Textual contents to include as-is in output.
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRaw

        public abstract void writeRaw(String text,
                              int offset,
                              int len)
                       throws IOException
        Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, use writeRawValue(String) instead.

        Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw UnsupportedOperationException.

        Parameters:
        text - String that has contents to include as-is in output
        offset - Offset within text of the first character to output
        len - Length of content (from text, starting at offset offset) to output
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRaw

        public abstract void writeRaw(char[] text,
                              int offset,
                              int len)
                       throws IOException
        Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, use writeRawValue(String) instead.

        Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw UnsupportedOperationException.

        Parameters:
        text - Buffer that has contents to include as-is in output
        offset - Offset within text of the first character to output
        len - Length of content (from text, starting at offset offset) to output
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRaw

        public abstract void writeRaw(char c)
                       throws IOException
        Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, use writeRawValue(String) instead.

        Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw UnsupportedOperationException.

        Parameters:
        c - Character to included in output
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRaw

        public void writeRaw(SerializableString raw)
              throws IOException
        Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, use writeRawValue(String) instead.

        Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw UnsupportedOperationException.

        The default implementation delegates to writeRaw(String); other backends that support raw inclusion of text are encouraged to implement it in more efficient manner (especially if they use UTF-8 encoding).

        Parameters:
        raw - Pre-encoded textual contents to included in output
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRawValue

        public abstract void writeRawValue(String text)
                            throws IOException
        Method that will force generator to copy input text verbatim without any modifications, but assuming it must constitute a single legal JSON value (number, string, boolean, null, Array or List). Assuming this, proper separators are added if and as needed (comma or colon), and generator state updated to reflect this.
        Parameters:
        text - Textual contents to included in output
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeRawValue

        public abstract void writeRawValue(char[] text,
                                   int offset,
                                   int len)
                            throws IOException
        Throws:
        IOException

      • writeBinary

        public abstract void writeBinary(Base64Variant bv,
                                 byte[] data,
                                 int offset,
                                 int len)
                          throws IOException
        Method that will output given chunk of binary data as base64 encoded, as a complete String value (surrounded by double quotes). This method defaults

        Note: because JSON Strings can not contain unescaped linefeeds, if linefeeds are included (as per last argument), they must be escaped. This adds overhead for decoding without improving readability. Alternatively if linefeeds are not included, resulting String value may violate the requirement of base64 RFC which mandates line-length of 76 characters and use of linefeeds. However, all JsonParser implementations are required to accept such "long line base64"; as do typical production-level base64 decoders.

        Parameters:
        bv - Base64 variant to use: defines details such as whether padding is used (and if so, using which character); what is the maximum line length before adding linefeed, and also the underlying alphabet to use.
        data - Buffer that contains binary data to write
        offset - Offset in data of the first byte of data to write
        len - Length of data to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeBinary

        public void writeBinary(byte[] data,
                        int offset,
                        int len)
                 throws IOException
        Similar to writeBinary(Base64Variant,byte[],int,int), but default to using the Jackson default Base64 variant (which is Base64Variants.MIME_NO_LINEFEEDS).
        Parameters:
        data - Buffer that contains binary data to write
        offset - Offset in data of the first byte of data to write
        len - Length of data to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeBinary

        public int writeBinary(InputStream data,
                       int dataLength)
                throws IOException
        Similar to writeBinary(Base64Variant,InputStream,int), but assumes default to using the Jackson default Base64 variant (which is Base64Variants.MIME_NO_LINEFEEDS).
        Parameters:
        data - InputStream to use for reading binary data to write. Will not be closed after successful write operation
        dataLength - (optional) number of bytes that will be available; or -1 to be indicate it is not known. Note that implementations need not support cases where length is not known in advance; this depends on underlying data format: JSON output does NOT require length, other formats may
        Returns:
        Number of bytes actually written
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeBinary

        public abstract int writeBinary(Base64Variant bv,
                                InputStream data,
                                int dataLength)
                         throws IOException
        Method similar to writeBinary(Base64Variant,byte[],int,int), but where input is provided through a stream, allowing for incremental writes without holding the whole input in memory.
        Parameters:
        bv - Base64 variant to use
        data - InputStream to use for reading binary data to write. Will not be closed after successful write operation
        dataLength - (optional) number of bytes that will be available; or -1 to be indicate it is not known. If a positive length is given, data MUST provide at least that many bytes: if not, an exception will be thrown. Note that implementations need not support cases where length is not known in advance; this depends on underlying data format: JSON output does NOT require length, other formats may.
        Returns:
        Number of bytes read from data and written as binary payload
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public void writeNumber(short v)
                 throws IOException
        Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.2

      • writeNumber

        public abstract void writeNumber(int v)
                          throws IOException
        Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(long v)
                          throws IOException
        Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(BigInteger v)
                          throws IOException
        Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(double v)
                          throws IOException
        Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(float v)
                          throws IOException
        Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(BigDecimal v)
                          throws IOException
        Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        v - Number value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumber

        public abstract void writeNumber(String encodedValue)
                          throws IOException
        Write method that can be used for custom numeric types that can not be (easily?) converted to "standard" Java number types. Because numbers are not surrounded by double quotes, regular writeString(java.lang.String) method can not be used; nor writeRaw(java.lang.String) because that does not properly handle value separators needed in Array or Object contexts.

        Note: because of lack of type safety, some generator implementations may not be able to implement this method. For example, if a binary JSON format is used, it may require type information for encoding; similarly for generator-wrappers around Java objects or JSON nodes. If implementation does not implement this method, it needs to throw UnsupportedOperationException.

        Parameters:
        encodedValue - Textual (possibly format) number representation to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        UnsupportedOperationException - If underlying data format does not support numbers serialized textually AND if generator is not allowed to just output a String instead (Schema-based formats may require actual number, for example)

      • writeNumber

        public void writeNumber(char[] encodedValueBuffer,
                        int offset,
                        int len)
                 throws IOException
        Overloaded version of writeNumber(String) with same semantics but possibly more efficient operation.
        Parameters:
        encodedValueBuffer - Buffer that contains the textual number representation to write
        offset - Offset of the first character of value to write
        len - Length of the value (in characters) to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.11

      • writeBoolean

        public abstract void writeBoolean(boolean state)
                           throws IOException
        Method for outputting literal JSON boolean value (one of Strings 'true' and 'false'). Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Parameters:
        state - Boolean value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNull

        public abstract void writeNull()
                        throws IOException
        Method for outputting literal JSON null value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeEmbeddedObject

        public void writeEmbeddedObject(Object object)
                         throws IOException
        Method that can be called on backends that support passing opaque native values that some data formats support; not used with JSON backend, more common with binary formats.

        NOTE: this is NOT the method to call for serializing regular POJOs, see writeObject(java.lang.Object) instead.

        Parameters:
        object - Native format-specific value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.8

      • writeObjectId

        public void writeObjectId(Object id)
                   throws IOException
        Method that can be called to output so-called native Object Id. Note that it may only be called after ensuring this is legal (with canWriteObjectId()), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, a JsonGenerationException will be thrown.
        Parameters:
        id - Native Object Id to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        JsonGenerationException - if Object ID output is not allowed (either at all, or specifically in this position in output)
        Since:
        2.3

      • writeObjectRef

        public void writeObjectRef(Object referenced)
                    throws IOException
        Method that can be called to output references to native Object Ids. Note that it may only be called after ensuring this is legal (with canWriteObjectId()), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, a JsonGenerationException will be thrown.
        Parameters:
        referenced - Referenced value, for which Object Id is expected to be written
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        JsonGenerationException - if Object ID output is not allowed (either at all, or specifically in this position in output)

      • writeTypeId

        public void writeTypeId(Object id)
                 throws IOException
        Method that can be called to output so-called native Type Id. Note that it may only be called after ensuring this is legal (with canWriteTypeId()), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, a JsonGenerationException will be thrown.
        Parameters:
        id - Native Type Id to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        JsonGenerationException - if Type ID output is not allowed (either at all, or specifically in this position in output)
        Since:
        2.3

      • writeTypePrefix

        public WritableTypeId writeTypePrefix(WritableTypeId typeIdDef)
                               throws IOException
        Replacement method for writeTypeId(Object) which is called regardless of whether format has native type ids. If it does have native type ids, those are to be used (if configuration allows this), if not, structural type id inclusion is to be used. For JSON, for example, no native type ids exist and structural inclusion is always used.

        NOTE: databind may choose to skip calling this method for some special cases (and instead included type id via regular write methods and/or writeTypeId(java.lang.Object) -- this is discouraged, but not illegal, and may be necessary as a work-around in some cases.

        Parameters:
        typeIdDef - Full Type Id definition
        Returns:
        WritableTypeId for caller to retain and pass to matching writeTypeSuffix(com.fasterxml.jackson.core.type.WritableTypeId) call
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        JsonGenerationException - if Type ID output is not allowed (either at all, or specifically in this position in output)
        Since:
        2.9

      • writeObject

        public abstract void writeObject(Object pojo)
                          throws IOException
        Method for writing given Java object (POJO) as Json. Exactly how the object gets written depends on object in question (ad on codec, its configuration); for most beans it will result in JSON Object, but for others JSON Array, or String or numeric value (and for nulls, JSON null literal. NOTE: generator must have its object codec set to non-null value; for generators created by a mapping factory this is the case, for others not.
        Parameters:
        pojo - General POJO value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeTree

        public abstract void writeTree(TreeNode rootNode)
                        throws IOException
        Method for writing given JSON tree (expressed as a tree where given JsonNode is the root) using this generator. This will generally just call writeObject(java.lang.Object) with given node, but is added for convenience and to make code more explicit in cases where it deals specifically with trees.
        Parameters:
        rootNode - TreeNode to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeBinaryField

        public void writeBinaryField(String fieldName,
                             byte[] data)
                      throws IOException
        Convenience method for outputting a field entry ("member") that contains specified data in base64-encoded form. Equivalent to: 
          writeFieldName(fieldName);
  writeBinary(value);
        Parameters:
        fieldName - Name of the field to write
        data - Binary data for the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeBooleanField

        public void writeBooleanField(String fieldName,
                              boolean value)
                       throws IOException
        Convenience method for outputting a field entry ("member") that has a boolean value. Equivalent to: 
          writeFieldName(fieldName);
  writeBoolean(value);
        Parameters:
        fieldName - Name of the field to write
        value - Boolean value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNullField

        public void writeNullField(String fieldName)
                    throws IOException
        Convenience method for outputting a field entry ("member") that has JSON literal value null. Equivalent to: 
          writeFieldName(fieldName);
  writeNull();
        Parameters:
        fieldName - Name of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeStringField

        public void writeStringField(String fieldName,
                             String value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has a String value. Equivalent to: 
          writeFieldName(fieldName);
  writeString(value);
        Parameters:
        fieldName - Name of the field to write
        value - String value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumberField

        public void writeNumberField(String fieldName,
                             short value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.11

      • writeNumberField

        public void writeNumberField(String fieldName,
                             int value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumberField

        public void writeNumberField(String fieldName,
                             long value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumberField

        public void writeNumberField(String fieldName,
                             BigInteger value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.11

      • writeNumberField

        public void writeNumberField(String fieldName,
                             float value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumberField

        public void writeNumberField(String fieldName,
                             double value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeNumberField

        public void writeNumberField(String fieldName,
                             BigDecimal value)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to: 
          writeFieldName(fieldName);
  writeNumber(value);
        Parameters:
        fieldName - Name of the field to write
        value - Numeric value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeArrayFieldStart

        public void writeArrayFieldStart(String fieldName)
                          throws IOException
        Convenience method for outputting a field entry ("member") (that will contain a JSON Array value), and the START_ARRAY marker. Equivalent to: 
          writeFieldName(fieldName);
  writeStartArray();

        Note: caller still has to take care to close the array (by calling {#link #writeEndArray}) after writing all values of the value Array.

        Parameters:
        fieldName - Name of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeObjectFieldStart

        public void writeObjectFieldStart(String fieldName)
                           throws IOException
        Convenience method for outputting a field entry ("member") (that will contain an Object value), and the START_OBJECT marker. Equivalent to: 
          writeFieldName(fieldName);
  writeStartObject();

        Note: caller still has to take care to close the Object (by calling {#link #writeEndObject}) after writing all entries of the value Object.

        Parameters:
        fieldName - Name of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeObjectField

        public void writeObjectField(String fieldName,
                             Object pojo)
                      throws IOException
        Convenience method for outputting a field entry ("member") that has contents of specific Java object as its value. Equivalent to: 
          writeFieldName(fieldName);
  writeObject(pojo);

        NOTE: actual serialization of POJO value requires assigned ObjectCodec and will delegate to that (usually ObjectMapper of databind layer)

        Parameters:
        fieldName - Name of the field to write
        pojo - POJO value of the field to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • writeOmittedField

        public void writeOmittedField(String fieldName)
                       throws IOException
        Method called to indicate that a property in this position was skipped. It is usually only called for generators that return false from canOmitFields().

        Default implementation does nothing.

        Parameters:
        fieldName - Name of the field omitted
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer
        Since:
        2.3

      • copyCurrentEvent

        public void copyCurrentEvent(JsonParser p)
                      throws IOException
        Method for copying contents of the current event that the given parser instance points to. Note that the method will not copy any other events, such as events contained within JSON Array or Object structures.

        Calling this method will not advance the given parser, although it may cause parser to internally process more data (if it lazy loads contents of value events, for example)

        Parameters:
        p - Parser that points to event (token) to copy
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • copyCurrentStructure

        public void copyCurrentStructure(JsonParser p)
                          throws IOException
        Method for copying contents of the current event and following events that it encloses the given parser instance points to.

        So what constitutes enclosing? Here is the list of events that have associated enclosed events that will get copied:

        After calling this method, parser will point to the last event that was copied. This will either be the event parser already pointed to (if there were no enclosed events), or the last enclosed event copied.

        Parameters:
        p - Parser that points to the value to copy
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • flush

        public abstract void flush()
                    throws IOException
        Method called to flush any buffered content to the underlying target (output stream, writer), and to flush the target itself as well.
        Specified by:
        flush in interface Flushable
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

      • isClosed

        public abstract boolean isClosed()
        Method that can be called to determine whether this generator is closed or not. If it is closed, no more output can be done.
        Returns:
        True if this generator instance has been closed

      • close

        public abstract void close()
                    throws IOException
        Method called to close this generator, so that no more content can be written.

        Whether the underlying target (stream, writer) gets closed depends on whether this generator either manages the target (i.e. is the only one with access to the target -- case if caller passes a reference to the resource such as File, but not stream); or has feature JsonGenerator.Feature.AUTO_CLOSE_TARGET enabled. If either of above is true, the target is also closed. Otherwise (not managing, feature not enabled), target is not closed.

        Specified by:
        close in interface Closeable
        Specified by:
        close in interface AutoCloseable
        Throws:
        IOException - if there is either an underlying I/O problem

      • _throwInternal

        protected final void _throwInternal()

      • _reportUnsupportedOperation

        protected void _reportUnsupportedOperation()

      • _verifyOffsets

        protected final void _verifyOffsets(int arrayLength,
                                    int offset,
                                    int length)

      • _writeSimpleObject

        protected void _writeSimpleObject(Object value)
                           throws IOException
        Helper method to try to call appropriate write method for given untyped Object. At this point, no structural conversions should be done, only simple basic types are to be coerced as necessary.
        Parameters:
        value - Value to write
        Throws:
        IOException - if there is either an underlying I/O problem or encoding issue at format layer

Copyright © 2008–2021 FasterXML. All rights reserved.