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

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

You can also browse Jackson Databind Source Code below:

⏎ com/fasterxml/jackson/databind/jsontype/impl/AsExternalTypeDeserializer.java

package com.fasterxml.jackson.databind.jsontype.impl;

import com.fasterxml.jackson.annotation.JsonTypeInfo.As;

import com.fasterxml.jackson.databind.BeanProperty;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
import com.fasterxml.jackson.databind.jsontype.TypeIdResolver;

/**
 * Type deserializer used with {@link As#EXTERNAL_PROPERTY} inclusion mechanism.
 * Actual implementation may look bit strange since it depends on comprehensive
 * pre-processing done by {@link com.fasterxml.jackson.databind.deser.BeanDeserializer}
 * to basically transform external type id into structure that looks more like
 * "wrapper-array" style inclusion. This intermediate form is chosen to allow
 * supporting all possible JSON structures.
 */
public class AsExternalTypeDeserializer extends AsArrayTypeDeserializer
{
    private static final long serialVersionUID = 1L;

    /**
     * @since 2.8
     */
    public AsExternalTypeDeserializer(JavaType bt, TypeIdResolver idRes,
            String typePropertyName, boolean typeIdVisible, JavaType defaultImpl)
    {
        super(bt, idRes, typePropertyName, typeIdVisible, defaultImpl);
    }

    public AsExternalTypeDeserializer(AsExternalTypeDeserializer src,
            BeanProperty property) {
        super(src, property);
    }

    @Override
    public TypeDeserializer forProperty(BeanProperty prop) {
        if (prop == _property) { // usually if it's null
            return this;
        }
        return new AsExternalTypeDeserializer(this, prop);
    }

    @Override
    public As getTypeInclusion() { return As.EXTERNAL_PROPERTY; }

    // yes, very important distinction...
    @Override
    protected boolean _usesExternalId() {
        return true;
    }
}

⏎ com/fasterxml/jackson/databind/jsontype/impl/AsExternalTypeDeserializer.java

Or download all of them as a single archive file:

File name: jackson-databind-2.14.0-sources.jar
File size: 1187952 bytes
Release date: 2022-11-05
Download 

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⇑⇑ Jackson - Java JSON library