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/json/async/NonBlockingJsonParser.java

package com.fasterxml.jackson.core.json.async;

import java.io.IOException;
import java.io.OutputStream;

import com.fasterxml.jackson.core.async.ByteArrayFeeder;
import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.core.sym.ByteQuadsCanonicalizer;

/**
 * Non-blocking parser implementation for JSON content that takes its input
 * via {@code byte[]} passed.
 *<p>
 * NOTE: only supports parsing of UTF-8 encoded content (and 7-bit US-ASCII since
 * it is strict subset of UTF-8): other encodings are not supported.
 *
 * @since 2.9
 */
public class NonBlockingJsonParser
    extends NonBlockingUtf8JsonParserBase
    implements ByteArrayFeeder
{
    private byte[] _inputBuffer = NO_BYTES;

    public NonBlockingJsonParser(IOContext ctxt, int parserFeatures,
                                 ByteQuadsCanonicalizer sym) {
        super(ctxt, parserFeatures, sym);
    }

    @Override
    public ByteArrayFeeder getNonBlockingInputFeeder() {
        return this;
    }

    @Override
    public void feedInput(final byte[] buf, final int start, final int end) throws IOException {
        // Must not have remaining input
        if (_inputPtr < _inputEnd) {
            _reportError("Still have %d undecoded bytes, should not call 'feedInput'", _inputEnd - _inputPtr);
        }
        if (end < start) {
            _reportError("Input end (%d) may not be before start (%d)", end, start);
        }
        // and shouldn't have been marked as end-of-input
        if (_endOfInput) {
            _reportError("Already closed, can not feed more input");
        }
        // Time to update pointers first
        _currInputProcessed += _origBufferLen;

        // Also need to adjust row start, to work as if it extended into the past wrt new buffer
        _currInputRowStart = start - (_inputEnd - _currInputRowStart);

        // And then update buffer settings
        _currBufferStart = start;
        _inputBuffer = buf;
        _inputPtr = start;
        _inputEnd = end;
        _origBufferLen = end - start;
    }

    @Override
    public int releaseBuffered(final OutputStream out) throws IOException {
        final int avail = _inputEnd - _inputPtr;
        if (avail > 0) {
            out.write(_inputBuffer, _inputPtr, avail);
        }
        return avail;
    }

    @Override
    protected byte getNextSignedByteFromBuffer() {
        return _inputBuffer[_inputPtr++];
    }

    @Override
    protected int getNextUnsignedByteFromBuffer() {
        return _inputBuffer[_inputPtr++] & 0xFF;
    }

    @Override
    protected byte getByteFromBuffer(final int ptr) {
        return _inputBuffer[ptr];
    }
}

⏎ com/fasterxml/jackson/core/json/async/NonBlockingJsonParser.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
Download 

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⇑⇑ Jackson - Java JSON library