Package com.fasterxml.jackson.core.util

Class ByteArrayBuilder

  • All Implemented Interfaces:
    BufferRecycler.Gettable, java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    public final class ByteArrayBuilder
extends java.io.OutputStream
implements BufferRecycler.Gettable
    Helper class that is similar to ByteArrayOutputStream in usage, but more geared to Jackson use cases internally. Specific changes include segment storage (no need to have linear backing buffer, can avoid reallocations, copying), as well API not based on OutputStream. In short, a very much specialized builder object.

    Also implements OutputStream to allow efficient aggregation of output content as a byte array, similar to how ByteArrayOutputStream works, but somewhat more efficiently for many use cases.

    NOTE: maximum size limited to Java Array maximum, 2 gigabytes: this because usage pattern is to collect content for a `byte[]` and so although theoretically this builder can aggregate more content it will not be usable as things are. Behavior may be improved if we solve the access problem.

    • Field Detail

      • NO_BYTES

        public static final byte[] NO_BYTES

    • Constructor Detail

      • ByteArrayBuilder

        public ByteArrayBuilder()

      • ByteArrayBuilder

        public ByteArrayBuilder​(int firstBlockSize)

      • ByteArrayBuilder

        public ByteArrayBuilder​(BufferRecycler br,
                        int firstBlockSize)

    • Method Detail

      • fromInitial

        public static ByteArrayBuilder fromInitial​(byte[] initialBlock,
                                           int length)

      • reset

        public void reset()

      • size

        public int size()
        Returns:
        Number of bytes aggregated so far
        Since:
        2.9

      • release

        public void release()
        Clean up method to call to release all buffers this object may be using. After calling the method, no other accessors can be used (and attempt to do so may result in an exception).

      • append

        public void append​(int i)

      • appendTwoBytes

        public void appendTwoBytes​(int b16)

      • appendThreeBytes

        public void appendThreeBytes​(int b24)

      • appendFourBytes

        public void appendFourBytes​(int b32)

      • toByteArray

        public byte[] toByteArray()
        Method called when results are finalized and we can get the full aggregated result buffer to return to the caller
        Returns:
        Aggregated contents as a byte[]

      • getClearAndRelease

        public byte[] getClearAndRelease()
        Method functionally same as calling: 
          byte[] bytes = toByteArray();
  release();
  return bytes;
        that is; aggregates output contained in the builder (if any), clear state; returns buffer(s) to BufferRecycler configured, if any, and returns output to caller.
        Since:
        2.17

      • resetAndGetFirstSegment

        public byte[] resetAndGetFirstSegment()
        Method called when starting "manual" output: will clear out current state and return the first segment buffer to fill
        Returns:
        Segment to use for writing

      • finishCurrentSegment

        public byte[] finishCurrentSegment()
        Method called when the current segment buffer is full; will append to current contents, allocate a new segment buffer and return it
        Returns:
        Segment to use for writing

      • completeAndCoalesce

        public byte[] completeAndCoalesce​(int lastBlockLength)
        Method that will complete "manual" output process, coalesce content (if necessary) and return results as a contiguous buffer.
        Parameters:
        lastBlockLength - Amount of content in the current segment buffer.
        Returns:
        Coalesced contents

      • getCurrentSegment

        public byte[] getCurrentSegment()

      • setCurrentSegmentLength

        public void setCurrentSegmentLength​(int len)

      • getCurrentSegmentLength

        public int getCurrentSegmentLength()

      • write

        public void write​(byte[] b)
        Overrides:
        write in class java.io.OutputStream

      • write

        public void write​(byte[] b,
                  int off,
                  int len)
        Overrides:
        write in class java.io.OutputStream

      • write

        public void write​(int b)
        Specified by:
        write in class java.io.OutputStream

      • close

        public void close()
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class java.io.OutputStream

      • flush

        public void flush()
        Specified by:
        flush in interface java.io.Flushable
        Overrides:
        flush in class java.io.OutputStream