Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Core Source Code files are provided in the source packge (jackson-core-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Core Source Code below:

⏎ com/fasterxml/jackson/core/util/BufferRecyclers.java

package com.fasterxml.jackson.core.util;

import java.lang.ref.SoftReference;

import com.fasterxml.jackson.core.io.JsonStringEncoder;

/**
 * Helper entity used to control access to simple buffer recyling scheme used for
 * some encoding, decoding tasks.
 *
 * @see BufferRecycler
 *
 * @since 2.9.2
 */
public class BufferRecyclers
{
    /**
     * System property that is checked to see if recycled buffers (see {@link BufferRecycler})
     * should be tracked, for purpose of forcing release of all such buffers, typically
     * during major classloading.
     *
     * @since 2.9.6
     */
    public final static String SYSTEM_PROPERTY_TRACK_REUSABLE_BUFFERS
        = "com.fasterxml.jackson.core.util.BufferRecyclers.trackReusableBuffers";

    /*
    /**********************************************************
    /* Life-cycle
    /**********************************************************
     */

    /**
     * Flag that indicates whether {@link BufferRecycler} instances should be tracked.
     */
    private final static ThreadLocalBufferManager _bufferRecyclerTracker;
    static {
        boolean trackReusableBuffers = false;
        try {
            trackReusableBuffers = "true".equals(System.getProperty(SYSTEM_PROPERTY_TRACK_REUSABLE_BUFFERS));
        } catch (SecurityException e) { }

        _bufferRecyclerTracker = trackReusableBuffers ? ThreadLocalBufferManager.instance() : null;
    }

    /*
    /**********************************************************
    /* BufferRecyclers for parsers, generators
    /**********************************************************
     */

    /**
     * This <code>ThreadLocal</code> contains a {@link java.lang.ref.SoftReference}
     * to a {@link BufferRecycler} used to provide a low-cost
     * buffer recycling between reader and writer instances.
     */
    final protected static ThreadLocal<SoftReference<BufferRecycler>> _recyclerRef
        = new ThreadLocal<SoftReference<BufferRecycler>>();

    /**
     * Main accessor to call for accessing possibly recycled {@link BufferRecycler} instance.
     *
     * @return {@link BufferRecycler} to use
     */
    public static BufferRecycler getBufferRecycler()
    {
        SoftReference<BufferRecycler> ref = _recyclerRef.get();
        BufferRecycler br = (ref == null) ? null : ref.get();

        if (br == null) {
            br = new BufferRecycler();
            if (_bufferRecyclerTracker != null) {
                ref = _bufferRecyclerTracker.wrapAndTrack(br);
            } else {
                ref = new SoftReference<BufferRecycler>(br);
            }
            _recyclerRef.set(ref);
        }
        return br;
    }

    /**
     * Specialized method that will release all recycled {@link BufferRecycler} if
     * (and only if) recycler tracking has been enabled
     * (see {@link #SYSTEM_PROPERTY_TRACK_REUSABLE_BUFFERS}).
     * This method is usually called on shutdown of the container like Application Server
     * to ensure that no references are reachable via {@link ThreadLocal}s as this may cause
     * unintentional retention of sizable amounts of memory. It may also be called regularly
     * if GC for some reason does not clear up {@link SoftReference}s aggressively enough.
     *
     * @return Number of buffers released, if tracking enabled (zero or more); -1 if tracking not enabled.
     *
     * @since 2.9.6
     */
    public static int releaseBuffers() {
        if (_bufferRecyclerTracker != null) {
            return _bufferRecyclerTracker.releaseBuffers();
        }
        return -1;
    }

    /*
    /**********************************************************************
    /* Obsolete things re-introduced in 2.12.5 after accidental direct
    /* removal from 2.10.0
    /**********************************************************************
     */

    /**
     * Not to be used any more: call {@link JsonStringEncoder#getInstance()} instead.
     *
     * @return {@code JsonStringEncoder} instance to use.
     *
     * @deprecated Since 2.10 (note: was accidentally removed but reintroduced as deprecated
     *    in 2.12.5, to be removed from 3.0)
     */
    @Deprecated
    public static JsonStringEncoder getJsonStringEncoder() {
        return JsonStringEncoder.getInstance();
    }

    /**
     * Not to be used any more: call {@link JsonStringEncoder#getInstance()} (and then
     * {@code encodeAsUTF8()}) instead.
     *
     * @param text String to encode
     * @return String encoded as UTF-8 bytes.
     *
     * @deprecated Since 2.10 (note: was accidentally removed but reintroduced as deprecated
     *    in 2.12.5, to be removed from 3.0)
     */
    @Deprecated
    public static byte[] encodeAsUTF8(String text) {
        return JsonStringEncoder.getInstance().encodeAsUTF8(text);
    }

    /**
     * Not to be used any more: call {@link JsonStringEncoder#getInstance()} (and then
     * {@code quoteAsString()}) instead.
     *
     * @param rawText String to quote
     *
     * @return Quoted text as {@code char[]}
     *
     * @deprecated Since 2.10 (note: was accidentally removed but reintroduced as deprecated
     *    in 2.12.5, to be removed from 3.0)
     */
    @Deprecated
    public static char[] quoteAsJsonText(String rawText) {
        return JsonStringEncoder.getInstance().quoteAsString(rawText);
    }

    /**
     * Not to be used any more: call {@link JsonStringEncoder#getInstance()} (and then
     * {@code quoteAsString()}) instead.
     *
     * @param input Textual content to quote
     * @param output Builder to append quoted content
     *
     * @deprecated Since 2.10 (note: was accidentally removed but reintroduced as deprecated
     *    in 2.12.5, to be removed from 3.0)
     */
    @Deprecated
    public static void quoteAsJsonText(CharSequence input, StringBuilder output) {
        JsonStringEncoder.getInstance().quoteAsString(input, output);
    }

    /**
     * Not to be used any more: call {@link JsonStringEncoder#getInstance()} (and then
     * {@code quoteAsUTF8()}) instead.
     *
     * @param rawText String to quote
     *
     * @return Quoted text as {@code byte[]}
     *
     * @deprecated Since 2.10 (note: was accidentally removed but reintroduced as deprecated
     *    in 2.12.5, to be removed from 3.0)
     */
    @Deprecated
    public static byte[] quoteAsJsonUTF8(String rawText) {
        return JsonStringEncoder.getInstance().quoteAsUTF8(rawText);
    }
}

⏎ com/fasterxml/jackson/core/util/BufferRecyclers.java

Or download all of them as a single archive file:

File name: jackson-core-2.14.0-sources.jar
File size: 497693 bytes
Release date: 2022-11-05
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