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/JsonParserDelegate.java

package com.fasterxml.jackson.core.util;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.math.BigDecimal;
import java.math.BigInteger;

import com.fasterxml.jackson.core.*;

/**
 * Helper class that implements
 * <a href="http://en.wikipedia.org/wiki/Delegation_pattern">delegation pattern</a> for {@link JsonParser},
 * to allow for simple overridability of basic parsing functionality.
 * The idea is that any functionality to be modified can be simply
 * overridden; and anything else will be delegated by default.
 */
public class JsonParserDelegate extends JsonParser
{
    /**
     * Delegate object that method calls are delegated to.
     */
    protected JsonParser delegate;

    public JsonParserDelegate(JsonParser d) {
        delegate = d;
    }

    /*
    /**********************************************************************
    /* Public API, configuration
    /**********************************************************************
     */

    @Override public void setCodec(ObjectCodec c) { delegate.setCodec(c); }
    @Override public ObjectCodec getCodec() { return delegate.getCodec(); }

    @Override
    public JsonParser enable(Feature f) {
        delegate.enable(f);
        return this;
    }

    @Override
    public JsonParser disable(Feature f) {
        delegate.disable(f);
        return this;
    }
 
    @Override public boolean isEnabled(Feature f) { return delegate.isEnabled(f); }
    @Override public int getFeatureMask() { return delegate.getFeatureMask(); }

    @Override
    @Deprecated // since 2.7
    public JsonParser setFeatureMask(int mask) {
        delegate.setFeatureMask(mask);
        return this;
    }

    @Override
    public JsonParser overrideStdFeatures(int values, int mask) {
        delegate.overrideStdFeatures(values, mask);
        return this;
    }

    @Override
    public JsonParser overrideFormatFeatures(int values, int mask) {
        delegate.overrideFormatFeatures(values, mask);
        return this;
    }

    @Override public FormatSchema getSchema() { return delegate.getSchema(); }
    @Override public void setSchema(FormatSchema schema) { delegate.setSchema(schema); }
    @Override public boolean canUseSchema(FormatSchema schema) {  return delegate.canUseSchema(schema); }
    @Override public Version version() { return delegate.version(); }
    @Override public Object getInputSource() { return delegate.getInputSource(); }

    /*
    /**********************************************************************
    /* Capability introspection
    /**********************************************************************
     */

    @Override public boolean requiresCustomCodec() { return delegate.requiresCustomCodec(); }

    @Override public JacksonFeatureSet<StreamReadCapability> getReadCapabilities() { return delegate.getReadCapabilities(); }

    /*
    /**********************************************************************
    /* Closeable impl
    /**********************************************************************
     */

    @Override public void close() throws IOException { delegate.close(); }
    @Override public boolean isClosed() { return delegate.isClosed(); }

    /*
    /**********************************************************************
    /* Public API, state change/override methods
    /**********************************************************************
     */

    @Override public void clearCurrentToken() { delegate.clearCurrentToken(); }
    @Override public JsonToken getLastClearedToken() { return delegate.getLastClearedToken(); }
    @Override public void overrideCurrentName(String name) { delegate.overrideCurrentName(name); }

    @Override // since 2.13
    public void assignCurrentValue(Object v) { delegate.assignCurrentValue(v); }

    // TODO: deprecate in 2.14 or later
    @Override
    public void setCurrentValue(Object v) { delegate.setCurrentValue(v); }

    /*
    /**********************************************************************
    /* Public API, state/location accessors
    /**********************************************************************
     */

    @Override public JsonStreamContext getParsingContext() { return delegate.getParsingContext(); }

    @Override public JsonToken currentToken() { return delegate.currentToken(); }
    @Override public int currentTokenId() { return delegate.currentTokenId(); }
    @Override public String currentName() throws IOException { return delegate.currentName(); }
    @Override // since 2.13
    public Object currentValue() { return delegate.currentValue(); }

    @Override // since 2.13
    public JsonLocation currentLocation() { return delegate.getCurrentLocation(); }
    @Override // since 2.13
    public JsonLocation currentTokenLocation() { return delegate.getTokenLocation(); }

    // TODO: deprecate in 2.14 or later
    @Override public JsonToken getCurrentToken() { return delegate.getCurrentToken(); }
    @Deprecated // since 2.12
    @Override public int getCurrentTokenId() { return delegate.getCurrentTokenId(); }
    // TODO: deprecate in 2.14 or later
    @Override public String getCurrentName() throws IOException { return delegate.getCurrentName(); }
    // TODO: deprecate in 2.14 or later
    @Override public Object getCurrentValue() { return delegate.getCurrentValue(); }

    // TODO: deprecate in 2.14 or later
    @Override public JsonLocation getCurrentLocation() { return delegate.getCurrentLocation(); }
    // TODO: deprecate in 2.14 or later
    @Override public JsonLocation getTokenLocation() { return delegate.getTokenLocation(); }

    /*
    /**********************************************************************
    /* Public API, token accessors
    /**********************************************************************
     */

    @Override public boolean hasCurrentToken() { return delegate.hasCurrentToken(); }
    @Override public boolean hasTokenId(int id) { return delegate.hasTokenId(id); }
    @Override public boolean hasToken(JsonToken t) { return delegate.hasToken(t); }

    @Override public boolean isExpectedStartArrayToken() { return delegate.isExpectedStartArrayToken(); }
    @Override public boolean isExpectedStartObjectToken() { return delegate.isExpectedStartObjectToken(); }
    @Override public boolean isExpectedNumberIntToken() { return delegate.isExpectedNumberIntToken(); }

    @Override public boolean isNaN() throws IOException { return delegate.isNaN(); }

    /*
    /**********************************************************************
    /* Public API, access to token textual content
    /**********************************************************************
     */

    @Override public String getText() throws IOException { return delegate.getText();  }
    @Override public boolean hasTextCharacters() { return delegate.hasTextCharacters(); }
    @Override public char[] getTextCharacters() throws IOException { return delegate.getTextCharacters(); }
    @Override public int getTextLength() throws IOException { return delegate.getTextLength(); }
    @Override public int getTextOffset() throws IOException { return delegate.getTextOffset(); }
    @Override public int getText(Writer writer) throws IOException, UnsupportedOperationException { return delegate.getText(writer);  }

    /*
    /**********************************************************************
    /* Public API, access to token numeric values
    /**********************************************************************
     */
    
    @Override
    public BigInteger getBigIntegerValue() throws IOException { return delegate.getBigIntegerValue(); }

    @Override
    public boolean getBooleanValue() throws IOException { return delegate.getBooleanValue(); }
    
    @Override
    public byte getByteValue() throws IOException { return delegate.getByteValue(); }

    @Override
    public short getShortValue() throws IOException { return delegate.getShortValue(); }

    @Override
    public BigDecimal getDecimalValue() throws IOException { return delegate.getDecimalValue(); }

    @Override
    public double getDoubleValue() throws IOException { return delegate.getDoubleValue(); }

    @Override
    public float getFloatValue() throws IOException { return delegate.getFloatValue(); }

    @Override
    public int getIntValue() throws IOException { return delegate.getIntValue(); }

    @Override
    public long getLongValue() throws IOException { return delegate.getLongValue(); }

    @Override
    public NumberType getNumberType() throws IOException { return delegate.getNumberType(); }

    @Override
    public Number getNumberValue() throws IOException { return delegate.getNumberValue(); }

    @Override
    public Number getNumberValueExact() throws IOException { return delegate.getNumberValueExact(); }

    /*
    /**********************************************************************
    /* Public API, access to token information, coercion/conversion
    /**********************************************************************
     */

    @Override public int getValueAsInt() throws IOException { return delegate.getValueAsInt(); }
    @Override public int getValueAsInt(int defaultValue) throws IOException { return delegate.getValueAsInt(defaultValue); }
    @Override public long getValueAsLong() throws IOException { return delegate.getValueAsLong(); }
    @Override public long getValueAsLong(long defaultValue) throws IOException { return delegate.getValueAsLong(defaultValue); }
    @Override public double getValueAsDouble() throws IOException { return delegate.getValueAsDouble(); }
    @Override public double getValueAsDouble(double defaultValue) throws IOException { return delegate.getValueAsDouble(defaultValue); }
    @Override public boolean getValueAsBoolean() throws IOException { return delegate.getValueAsBoolean(); }
    @Override public boolean getValueAsBoolean(boolean defaultValue) throws IOException { return delegate.getValueAsBoolean(defaultValue); }
    @Override public String getValueAsString() throws IOException { return delegate.getValueAsString(); }
    @Override public String getValueAsString(String defaultValue) throws IOException { return delegate.getValueAsString(defaultValue); }

    /*
    /**********************************************************************
    /* Public API, access to token values, other
    /**********************************************************************
     */

    @Override public Object getEmbeddedObject() throws IOException { return delegate.getEmbeddedObject(); }
    @Override public byte[] getBinaryValue(Base64Variant b64variant) throws IOException { return delegate.getBinaryValue(b64variant); }
    @Override public int readBinaryValue(Base64Variant b64variant, OutputStream out) throws IOException { return delegate.readBinaryValue(b64variant, out); }

    @Override public JsonToken nextToken() throws IOException { return delegate.nextToken(); }

    @Override public JsonToken nextValue() throws IOException { return delegate.nextValue(); }

    @Override public void finishToken() throws IOException { delegate.finishToken(); }
    
    @Override
    public JsonParser skipChildren() throws IOException {
        delegate.skipChildren();
        // NOTE: must NOT delegate this method to delegate, needs to be self-reference for chaining
        return this;
    }

    /*
    /**********************************************************************
    /* Public API, Native Ids (type, object)
    /**********************************************************************
     */

    @Override public boolean canReadObjectId() { return delegate.canReadObjectId(); }
    @Override public boolean canReadTypeId() { return delegate.canReadTypeId(); }
    @Override public Object getObjectId() throws IOException { return delegate.getObjectId(); }
    @Override public Object getTypeId() throws IOException { return delegate.getTypeId(); }

    /*
    /**********************************************************************
    /* Extended API
    /**********************************************************************
     */

    /**
     * Accessor for getting the immediate {@link JsonParser} this parser delegates calls to.
     *
     * @return Underlying parser calls are delegated to
     *
     * @since 2.10
     */
    public JsonParser delegate() { return delegate; }
}

⏎ com/fasterxml/jackson/core/util/JsonParserDelegate.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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