Package com.fasterxml.jackson.core.util

Class TextBuffer

java.lang.Object
com.fasterxml.jackson.core.util.TextBuffer
Direct Known Subclasses:
ReadConstrainedTextBuffer
public class TextBuffer extends Object
TextBuffer is a class similar to StringBuffer, with following differences:
  • TextBuffer uses segments character arrays, to avoid having to do additional array copies when array is not big enough. This means that only reallocating that is necessary is done only once: if and when caller wants to access contents in a linear array (char[], String).
  • TextBuffer can also be initialized in "shared mode", in which it will just act as a wrapper to a single char array managed by another object (like parser that owns it)
  • TextBuffer is not synchronized.

  • Constructor Details

    • TextBuffer

      public TextBuffer(BufferRecycler allocator)

    • TextBuffer

      protected TextBuffer(BufferRecycler allocator, char[] initialSegment)

  • Method Details

    • fromInitial

      public static TextBuffer fromInitial(char[] initialSegment)
      Factory method for constructing an instance with no allocator, and with initial full segment.
      Parameters:
      initialSegment - Initial, full segment to use for creating buffer (buffer size() would return length of initialSegment)
      Returns:
      TextBuffer constructed
      Since:
      2.10

    • releaseBuffers

      public void releaseBuffers()
      Method called to indicate that the underlying buffers should now be recycled if they haven't yet been recycled. Although caller can still use this text buffer, it is not advisable to call this method if that is likely, since next time a buffer is needed, buffers need to reallocated.

      Note: since Jackson 2.11, calling this method will NOT clear already aggregated contents (that is, _currentSegment, to retain current token text if (but only if!) already aggregated.

    • resetWithEmpty

      public void resetWithEmpty()
      Method called to clear out any content text buffer may have, and initializes buffer to use non-shared data.

    • resetWith

      public void resetWith(char ch)
      Method for clearing out possibly existing content, and replacing them with a single-character content (so size() would return 1)
      Parameters:
      ch - Character to set as the buffer contents
      Since:
      2.9

    • resetWithShared

      public void resetWithShared(char[] buf, int offset, int len)
      Method called to initialize the buffer with a shared copy of data; this means that buffer will just have pointers to actual data. It also means that if anything is to be appended to the buffer, it will first have to unshare it (make a local copy).
      Parameters:
      buf - Buffer that contains shared contents
      offset - Offset of the first content character in buf
      len - Length of content in buf

    • resetWithCopy

      public void resetWithCopy(char[] buf, int offset, int len) throws IOException
      Parameters:
      buf - Buffer that contains new contents
      offset - Offset of the first content character in buf
      len - Length of content in buf
      Throws:
      IOException - if the buffer has grown too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • resetWithCopy

      public void resetWithCopy(String text, int start, int len) throws IOException
      Parameters:
      text - String that contains new contents
      start - Offset of the first content character in text
      len - Length of content in text
      Throws:
      IOException - if the buffer has grown too large, see StreamReadConstraints.Builder.maxStringLength(int)
      Since:
      2.9

    • resetWithString

      public void resetWithString(String value) throws IOException
      Parameters:
      value - to replace existing buffer
      Throws:
      IOException - if the value is too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • getBufferWithoutReset

      public char[] getBufferWithoutReset()
      Method for accessing the currently active (last) content segment without changing state of the buffer
      Returns:
      Currently active (last) content segment
      Since:
      2.9

    • size

      public int size()
      Returns:
      Number of characters currently stored in this buffer

    • getTextOffset

      public int getTextOffset()

    • hasTextAsCharacters

      public boolean hasTextAsCharacters()
      Method that can be used to check whether textual contents can be efficiently accessed using getTextBuffer().
      Returns:
      True if access via getTextBuffer() would be efficient (that is, content already available as aggregated char[])

    • getTextBuffer

      public char[] getTextBuffer() throws IOException
      Accessor that may be used to get the contents of this buffer as a single char[] regardless of whether they were collected in a segmented fashion or not: this typically require allocation of the result buffer.
      Returns:
      Aggregated char[] that contains all buffered content
      Throws:
      IOException - if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • contentsAsString

      public String contentsAsString() throws IOException
      Accessor that may be used to get the contents of this buffer as a single String regardless of whether they were collected in a segmented fashion or not: this typically require construction of the result String.
      Returns:
      Aggregated buffered contents as a String
      Throws:
      IOException - if the contents are too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • contentsAsArray

      public char[] contentsAsArray() throws IOException
      Returns:
      char array
      Throws:
      IOException - if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • contentsAsDouble

      public double contentsAsDouble(boolean useFastParser) throws NumberFormatException
      Convenience method for converting contents of the buffer into a Double value.
      Parameters:
      useFastParser - whether to use FastDoubleParser
      Returns:
      Buffered text value parsed as a Double, if possible
      Throws:
      NumberFormatException - if contents are not a valid Java number
      Since:
      2.14

    • contentsAsDouble

      @Deprecated public double contentsAsDouble() throws NumberFormatException
      Deprecated.
      use contentsAsDouble(boolean)
      Convenience method for converting contents of the buffer into a Double value.
      Returns:
      Buffered text value parsed as a Double, if possible
      Throws:
      NumberFormatException - if contents are not a valid Java number

    • contentsAsFloat

      @Deprecated public float contentsAsFloat() throws NumberFormatException
      Deprecated.
      use contentsAsFloat(boolean)
      Convenience method for converting contents of the buffer into a Float value.
      Returns:
      Buffered text value parsed as a Float, if possible
      Throws:
      NumberFormatException - if contents are not a valid Java number

    • contentsAsFloat

      public float contentsAsFloat(boolean useFastParser) throws NumberFormatException
      Convenience method for converting contents of the buffer into a Float value.
      Parameters:
      useFastParser - whether to use FastDoubleParser
      Returns:
      Buffered text value parsed as a Float, if possible
      Throws:
      NumberFormatException - if contents are not a valid Java number
      Since:
      2.14

    • contentsAsDecimal

      @Deprecated public BigDecimal contentsAsDecimal() throws NumberFormatException
      Deprecated.
      Since 2.15 just access String contents if necessary, call NumberInput.parseBigDecimal(String, boolean) (or other overloads) directly instead
      Returns:
      Buffered text value parsed as a BigDecimal, if possible
      Throws:
      NumberFormatException - if contents are not a valid Java number

    • contentsAsInt

      public int contentsAsInt(boolean neg)
      Specialized convenience method that will decode a 32-bit int, of at most 9 digits (and possible leading minus sign).

      NOTE: method DOES NOT verify that the contents actually are a valid Java int value (either regarding format, or value range): caller MUST validate that.

      Parameters:
      neg - Whether contents start with a minus sign
      Returns:
      Buffered text value parsed as an int using NumberInput.parseInt(String) method (which does NOT validate input)
      Since:
      2.9

    • contentsAsLong

      public long contentsAsLong(boolean neg)
      Specialized convenience method that will decode a 64-bit int, of at most 18 digits (and possible leading minus sign).

      NOTE: method DOES NOT verify that the contents actually are a valid Java long value (either regarding format, or value range): caller MUST validate that.

      Parameters:
      neg - Whether contents start with a minus sign
      Returns:
      Buffered text value parsed as an long using NumberInput.parseLong(String) method (which does NOT validate input)
      Since:
      2.9

    • contentsToWriter

      public int contentsToWriter(Writer w) throws IOException
      Accessor that will write buffered contents using given Writer.
      Parameters:
      w - Writer to use for writing out buffered content
      Returns:
      Number of characters written (same as size())
      Throws:
      IOException - If write using Writer parameter fails
      Since:
      2.8

    • ensureNotShared

      public void ensureNotShared()
      Method called to make sure that buffer is not using shared input buffer; if it is, it will copy such contents to private buffer.

    • append

      public void append(char c) throws IOException
      Parameters:
      c - char to append
      Throws:
      IOException - if the buffer has grown too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • append

      public void append(char[] c, int start, int len) throws IOException
      Parameters:
      c - char array to append
      start - the start index within the array (from which we read chars to append)
      len - number of chars to take from the array
      Throws:
      IOException - if the buffer has grown too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • append

      public void append(String str, int offset, int len) throws IOException
      Parameters:
      str - string to append
      offset - the start index within the string (from which we read chars to append)
      len - number of chars to take from the string
      Throws:
      IOException - if the buffer has grown too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • getCurrentSegment

      public char[] getCurrentSegment()

    • emptyAndGetCurrentSegment

      public char[] emptyAndGetCurrentSegment()

    • getCurrentSegmentSize

      public int getCurrentSegmentSize()

    • setCurrentLength

      public void setCurrentLength(int len)

    • setCurrentAndReturn

      public String setCurrentAndReturn(int len) throws IOException
      Convenience method that finishes the current active content segment (by specifying how many characters within consists of valid content) and aggregates and returns resulting contents (similar to a call to contentsAsString()).
      Parameters:
      len - Length of content (in characters) of the current active segment
      Returns:
      String that contains all buffered content
      Throws:
      IOException - if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)
      Since:
      2.6

    • finishCurrentSegment

      public char[] finishCurrentSegment() throws IOException
      Returns:
      char array
      Throws:
      IOException - if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)

    • finishAndReturn

      public String finishAndReturn(int lastSegmentEnd, boolean trimTrailingSpaces) throws IOException
      Parameters:
      lastSegmentEnd - End offset in the currently active segment, could be 0 in the case of first character is delimiter or end-of-line
      trimTrailingSpaces - Whether trailing spaces should be trimmed or not
      Returns:
      token as text
      Throws:
      IOException - If length constraints (of longest allowed Text value) are violated
      Since:
      2.15

    • expandCurrentSegment

      public char[] expandCurrentSegment()
      Method called to expand size of the current segment, to accommodate for more contiguous content. Usually only used when parsing tokens like names if even then. Method will both expand the segment and return it
      Returns:
      Expanded current segment

    • expandCurrentSegment

      public char[] expandCurrentSegment(int minSize)
      Method called to expand size of the current segment, to accommodate for more contiguous content. Usually only used when parsing tokens like names if even then.
      Parameters:
      minSize - Required minimum strength of the current segment
      Returns:
      Expanded current segment
      Since:
      2.4

    • toString

      public String toString()
      Note: calling this method may not be as efficient as calling contentsAsString(), since it's not guaranteed that resulting String is cached.
      Overrides:
      toString in class Object

    • _reportBufferOverflow

      protected void _reportBufferOverflow(int prev, int curr)

    • validateStringLength

      protected void validateStringLength(int length) throws IOException
      Convenience method that can be used to verify that a String of specified length does not exceed maximum specific by this constraints object: if it does, a JsonParseException is thrown.
      Parameters:
      length - Length of string in input units
      Throws:
      IOException - If length exceeds maximum
      Since:
      2.15