com.fasterxml.jackson.core.json

Class UTF8DataInputJsonParser

  • All Implemented Interfaces:
    Versioned, Closeable, AutoCloseable


    public class UTF8DataInputJsonParser
    extends ParserBase
    This is a concrete implementation of JsonParser, which is based on a DataInput as the input source.

    Due to limitations in look-ahead (basically there's none), as well as overhead of reading content mostly byte-by-byte, there are some minor differences from regular streaming parsing. Specifically:

    • Input location offsets not being tracked, as offsets would need to be updated for each read from all over the place. If caller wants this information, it has to track this with DataInput. This also affects column number, so the only location information available is the row (line) number (but even that is approximate in case of two-byte linefeeds -- it should work with single CR or LF tho)
    • No white space validation: checks are simplified NOT to check for control characters.

    Since:
    2.8
    • Field Detail

      • _icLatin1

        protected static final int[] _icLatin1
      • _objectCodec

        protected ObjectCodec _objectCodec
        Codec used for data binding when (if) requested; typically full ObjectMapper, but that abstract is not part of core package.
      • _symbols

        protected final ByteQuadsCanonicalizer _symbols
        Symbol table that contains field names encountered so far
      • _quadBuffer

        protected int[] _quadBuffer
        Temporary buffer used for name parsing.
      • _tokenIncomplete

        protected boolean _tokenIncomplete
        Flag that indicates that the current token has not yet been fully processed, and needs to be finished for some access (or skipped to obtain the next token)
      • _nextByte

        protected int _nextByte
        Sometimes we need buffering for just a single byte we read but have to "push back"
    • Method Detail

      • getReadCapabilities

        public JacksonFeatureSet<StreamReadCapability> getReadCapabilities()
        Description copied from class: JsonParser
        Accessor for getting metadata on capabilities of this parser, based on underlying data format being read (directly or indirectly).
        Overrides:
        getReadCapabilities in class JsonParser
        Returns:
        Set of read capabilities for content to read via this parser
      • releaseBuffered

        public int releaseBuffered(OutputStream out)
                            throws IOException
        Description copied from class: JsonParser
        Method that can be called to push back any content that has been read but not consumed by the parser. This is usually done after reading all content of interest using parser. Content is released by writing it to given stream if possible; if underlying input is byte-based it can released, if not (char-based) it can not.
        Overrides:
        releaseBuffered in class JsonParser
        Returns:
        -1 if the underlying content source is not byte based (that is, input can not be sent to OutputStream; otherwise number of bytes released (0 if there was nothing to release)
        Throws:
        IOException - if write to stream threw exception
      • getInputSource

        public Object getInputSource()
        Description copied from class: JsonParser
        Method that can be used to get access to object that is used to access input being parsed; this is usually either InputStream or Reader, depending on what parser was constructed with. Note that returned value may be null in some cases; including case where parser implementation does not want to exposed raw source to caller. In cases where input has been decorated, object returned here is the decorated version; this allows some level of interaction between users of parser 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.

        Overrides:
        getInputSource in class JsonParser
      • _releaseBuffers

        protected void _releaseBuffers()
                                throws IOException
        Method called to release internal buffers owned by the base reader. This may be called along with _closeInput() (for example, when explicitly closing this reader instance), or separately (if need be).
        Overrides:
        _releaseBuffers in class ParserBase
        Throws:
        IOException
      • getText

        public int getText(Writer writer)
                    throws IOException
        Description copied from class: JsonParser
        Method to read the textual representation of the current token in chunks and pass it to the given Writer. Conceptually same as calling:
          writer.write(parser.getText());
        
        but should typically be more efficient as longer content does need to be combined into a single String to return, and write can occur directly from intermediate buffers Jackson uses.
        Overrides:
        getText in class JsonParser
        Returns:
        The number of characters written to the Writer
        Throws:
        IOException
      • getValueAsString

        public String getValueAsString()
                                throws IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a String. JSON Strings map naturally; scalar values get converted to their textual representation. If representation can not be converted to a String value (including structured types like Objects and Arrays and null token), default value of null will be returned; no exceptions are thrown.
        Overrides:
        getValueAsString in class ParserMinimalBase
        Throws:
        IOException
      • getValueAsString

        public String getValueAsString(String defValue)
                                throws IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a String. JSON Strings map naturally; scalar values get converted to their textual representation. If representation can not be converted to a String value (including structured types like Objects and Arrays and null token), specified default value will be returned; no exceptions are thrown.
        Overrides:
        getValueAsString in class ParserMinimalBase
        Throws:
        IOException
      • getValueAsInt

        public int getValueAsInt()
                          throws IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

        If representation can not be converted to an int (including structured type markers like start/end Object/Array) default value of 0 will be returned; no exceptions are thrown.

        Overrides:
        getValueAsInt in class ParserMinimalBase
        Throws:
        IOException
      • getValueAsInt

        public int getValueAsInt(int defValue)
                          throws IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

        If representation can not be converted to an int (including structured type markers like start/end Object/Array) specified def will be returned; no exceptions are thrown.

        Overrides:
        getValueAsInt in class ParserMinimalBase
        Throws:
        IOException
      • getTextCharacters

        public char[] getTextCharacters()
                                 throws IOException
        Description copied from class: JsonParser
        Method similar to JsonParser.getText(), but that will return underlying (unmodifiable) character array that contains textual value, instead of constructing a String object to contain this information. Note, however, that:
        • Textual contents are not guaranteed to start at index 0 (rather, call JsonParser.getTextOffset()) to know the actual offset
        • Length of textual contents may be less than the length of returned buffer: call JsonParser.getTextLength() for actual length of returned content.

        Note that caller MUST NOT modify the returned character array in any way -- doing so may corrupt current parser state and render parser instance useless.

        The only reason to call this method (over JsonParser.getText()) is to avoid construction of a String object (which will make a copy of contents).

        Specified by:
        getTextCharacters in class ParserMinimalBase
        Throws:
        IOException
      • getBinaryValue

        public byte[] getBinaryValue(Base64Variant b64variant)
                              throws IOException
        Description copied from class: JsonParser
        Method that can be used to read (and consume -- results may not be accessible using other methods after the call) base64-encoded binary data included in the current textual JSON value. It works similar to getting String value via JsonParser.getText() and decoding result (except for decoding part), but should be significantly more performant.

        Note that non-decoded textual contents of the current token are not guaranteed to be accessible after this method is called. Current implementation, for example, clears up textual content during decoding. Decoded binary content, however, will be retained until parser is advanced to the next event.

        Overrides:
        getBinaryValue in class ParserBase
        Parameters:
        b64variant - Expected variant of base64 encoded content (see Base64Variants for definitions of "standard" variants).
        Returns:
        Decoded binary data
        Throws:
        IOException
      • nextToken

        public JsonToken nextToken()
                            throws IOException
        Description copied from class: JsonParser
        Main iteration method, which will advance stream enough to determine type of the next token, if any. If none remaining (stream has no content other than possible white space before ending), null will be returned.
        Specified by:
        nextToken in class ParserMinimalBase
        Returns:
        Next token from the stream, if any found, or null to indicate end-of-input
        Throws:
        IOException
      • finishToken

        public void finishToken()
                         throws IOException
        Description copied from class: JsonParser
        Method that may be used to force full handling of the current token so that even if lazy processing is enabled, the whole contents are read for possible retrieval. This is usually used to ensure that the token end location is available, as well as token contents (similar to what calling, say JsonParser.getTextCharacters(), would achieve).

        Note that for many dataformat implementations this method will not do anything; this is the default implementation unless overridden by sub-classes.

        Overrides:
        finishToken in class JsonParser
        Throws:
        IOException
      • nextTextValue

        public String nextTextValue()
                             throws IOException
        Description copied from class: JsonParser
        Method that fetches next token (as if calling JsonParser.nextToken()) and if it is JsonToken.VALUE_STRING returns contained String value; otherwise returns null. It is functionally equivalent to:
          return (nextToken() == JsonToken.VALUE_STRING) ? getText() : null;
        
        but may be faster for parser to process, and can therefore be used if caller expects to get a String value next from input.
        Overrides:
        nextTextValue in class JsonParser
        Throws:
        IOException
      • nextIntValue

        public int nextIntValue(int defaultValue)
                         throws IOException
        Description copied from class: JsonParser
        Method that fetches next token (as if calling JsonParser.nextToken()) and if it is JsonToken.VALUE_NUMBER_INT returns 32-bit int value; otherwise returns specified default value It is functionally equivalent to:
          return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getIntValue() : defaultValue;
        
        but may be faster for parser to process, and can therefore be used if caller expects to get an int value next from input.
        Overrides:
        nextIntValue in class JsonParser
        Throws:
        IOException
      • nextLongValue

        public long nextLongValue(long defaultValue)
                           throws IOException
        Description copied from class: JsonParser
        Method that fetches next token (as if calling JsonParser.nextToken()) and if it is JsonToken.VALUE_NUMBER_INT returns 64-bit long value; otherwise returns specified default value It is functionally equivalent to:
          return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getLongValue() : defaultValue;
        
        but may be faster for parser to process, and can therefore be used if caller expects to get a long value next from input.
        Overrides:
        nextLongValue in class JsonParser
        Throws:
        IOException
      • nextBooleanValue

        public Boolean nextBooleanValue()
                                 throws IOException
        Description copied from class: JsonParser
        Method that fetches next token (as if calling JsonParser.nextToken()) and if it is JsonToken.VALUE_TRUE or JsonToken.VALUE_FALSE returns matching Boolean value; otherwise return null. It is functionally equivalent to:
          JsonToken t = nextToken();
          if (t == JsonToken.VALUE_TRUE) return Boolean.TRUE;
          if (t == JsonToken.VALUE_FALSE) return Boolean.FALSE;
          return null;
        
        but may be faster for parser to process, and can therefore be used if caller expects to get a Boolean value next from input.
        Overrides:
        nextBooleanValue in class JsonParser
        Throws:
        IOException
      • _parsePosNumber

        protected JsonToken _parsePosNumber(int c)
                                     throws IOException
        Initial parsing method for number values. It needs to be able to parse enough input to be able to determine whether the value is to be considered a simple integer value, or a more generic decimal value: latter of which needs to be expressed as a floating point number. The basic rule is that if the number has no fractional or exponential part, it is an integer; otherwise a floating point number.

        Because much of input has to be processed in any case, no partial parsing is done: all input text will be stored for further processing. However, actual numeric value conversion will be deferred, since it is usually the most complicated and costliest part of processing.

        Throws:
        IOException
      • parseEscapedName

        protected final String parseEscapedName(int[] quads,
                                                int qlen,
                                                int currQuad,
                                                int ch,
                                                int currQuadBytes)
                                         throws IOException
        Slower parsing method which is generally branched to when an escape sequence is detected (or alternatively for long names, one crossing input buffer boundary). Needs to be able to handle more exceptional cases, gets slower, and hance is offlined to a separate method.
        Throws:
        IOException
      • _handleOddName

        protected String _handleOddName(int ch)
                                 throws IOException
        Method called when we see non-white space character other than double quote, when expecting a field name. In standard mode will just throw an exception; but in non-standard modes may be able to parse name.
        Throws:
        IOException
      • _skipString

        protected void _skipString()
                            throws IOException
        Method called to skim through rest of unparsed String value, if it is not needed. This can be done bit faster if contents need not be stored for future access.
        Throws:
        IOException
      • _handleUnexpectedValue

        protected JsonToken _handleUnexpectedValue(int c)
                                            throws IOException
        Method for handling cases where first non-space character of an expected value token is not legal for standard JSON content.
        Throws:
        IOException
      • _handleInvalidNumberStart

        protected JsonToken _handleInvalidNumberStart(int ch,
                                                      boolean neg)
                                               throws IOException
        Method called if expected numeric value (due to leading sign) does not look like a number
        Throws:
        IOException
      • _decodeEscaped

        protected char _decodeEscaped()
                               throws IOException
        Description copied from class: ParserBase
        Method that sub-classes must implement to support escaped sequences in base64-encoded sections. Sub-classes that do not need base64 support can leave this as is
        Overrides:
        _decodeEscaped in class ParserBase
        Throws:
        IOException
      • _decodeCharForError

        protected int _decodeCharForError(int firstByte)
                                   throws IOException
        Throws:
        IOException
      • _decodeBase64

        protected final byte[] _decodeBase64(Base64Variant b64variant)
                                      throws IOException
        Efficient handling for incremental parsing of base64-encoded textual content.
        Throws:
        IOException
      • getTokenLocation

        public JsonLocation getTokenLocation()
        Description copied from class: ParserBase
        Method that return the starting location of the current token; that is, position of the first character from input that starts the current token.
        Overrides:
        getTokenLocation in class ParserBase
      • getCurrentLocation

        public JsonLocation getCurrentLocation()
        Description copied from class: ParserBase
        Method that returns location of the last processed character; usually for error reporting purposes
        Overrides:
        getCurrentLocation in class ParserBase

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