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/format/DataFormatMatcher.java

package com.fasterxml.jackson.core.format;

import java.io.*;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.io.MergedStream;

/**
 * Result object constructed by {@link DataFormatDetector} when requested
 * to detect format of given input data.
 */
public class DataFormatMatcher
{
    protected final InputStream _originalStream;

    /**
     * Content read during format matching process
     */
    protected final byte[] _bufferedData;

    /**
     * Pointer to the first byte in buffer available for reading
     */
    protected final int _bufferedStart;
    
    /**
     * Number of bytes available in buffer.
     */
    protected final int _bufferedLength;

    /**
     * Factory that produced sufficient match (if any)
     */
    protected final JsonFactory _match;

    /**
     * Strength of match with {@link #_match}
     */
    protected final MatchStrength _matchStrength;
    
    protected DataFormatMatcher(InputStream in, byte[] buffered,
            int bufferedStart, int bufferedLength,
            JsonFactory match, MatchStrength strength)
    {
        _originalStream = in;
        _bufferedData = buffered;
        _bufferedStart = bufferedStart;
        _bufferedLength = bufferedLength;
        _match = match;
        _matchStrength = strength;

        // can't have negative offset or length
        if ((bufferedStart | bufferedLength) < 0
                || (bufferedStart + bufferedLength) > buffered.length) {
            throw new IllegalArgumentException(String.format("Illegal start/length (%d/%d) wrt input array of %d bytes",
                    bufferedStart, bufferedLength, buffered.length));
        }
    }

    /*
    /**********************************************************
    /* Public API, simple accessors
    /**********************************************************
     */

    /**
     * Accessor to use to see if any formats matched well enough with
     * the input data.
     *
     * @return Whether format has a match
     */
    public boolean hasMatch() { return _match != null; }

    /**
     * Method for accessing strength of the match, if any; if no match,
     * will return {@link MatchStrength#INCONCLUSIVE}.
     *
     * @return Strength of match
     */
    public MatchStrength getMatchStrength() {
        return (_matchStrength == null) ? MatchStrength.INCONCLUSIVE : _matchStrength;
    }

    /**
     * Accessor for {@link JsonFactory} that represents format that data matched.
     *
     * @return Relevant {@link JsonFactory} to indicate matched format
     */
    public JsonFactory getMatch() { return _match; }

    /**
     * Accessor for getting brief textual name of matched format if any (null
     * if none). Equivalent to:
     *<pre>
     *   return hasMatch() ? getMatch().getFormatName() : null;
     *</pre>
     *
     * @return Name of the format that is acceptable match, if any; {@code null} if none
     */
    public String getMatchedFormatName() {
        return hasMatch() ? getMatch().getFormatName() : null;
    }
    
    /*
    /**********************************************************
    /* Public API, factory methods
    /**********************************************************
     */
    
    // Convenience method for trying to construct a {@link JsonParser} for
    // parsing content which is assumed to be in detected data format.
    // If no match was found, returns null.
    public JsonParser createParserWithMatch() throws IOException {
        if (_match == null) {
            return null;
        }
        if (_originalStream == null) {
            return _match.createParser(_bufferedData, _bufferedStart, _bufferedLength);
        }
        return _match.createParser(getDataStream());
    }
    
    /**
     * Method to use for accessing input for which format detection has been done.
     * This <b>must</b> be used instead of using stream passed to detector
     * unless given stream itself can do buffering.
     * Stream will return all content that was read during matching process, as well
     * as remaining contents of the underlying stream.
     *
     * @return InputStream to use for reading actual content using format detected
     */
    public InputStream getDataStream() {
        if (_originalStream == null) {
            return new ByteArrayInputStream(_bufferedData, _bufferedStart, _bufferedLength);
        }
        return new MergedStream(null, _originalStream, _bufferedData, _bufferedStart, _bufferedLength);
    }
}

⏎ com/fasterxml/jackson/core/format/DataFormatMatcher.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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