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

Jackson Annotations Source Code files are provided in the source packge (jackson-annotations-2.12.4-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Annotations Source Code below:

⏎ com/fasterxml/jackson/databind/ser/impl/PropertyBasedObjectIdGenerator.java

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

import com.fasterxml.jackson.annotation.ObjectIdGenerator;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;

import com.fasterxml.jackson.databind.introspect.ObjectIdInfo;
import com.fasterxml.jackson.databind.ser.*;

public class PropertyBasedObjectIdGenerator
    extends ObjectIdGenerators.PropertyGenerator
{
    private static final long serialVersionUID = 1L;

    protected final BeanPropertyWriter _property;
    
    public PropertyBasedObjectIdGenerator(ObjectIdInfo oid, BeanPropertyWriter prop)
    {
        this(oid.getScope(), prop);
    }

    protected PropertyBasedObjectIdGenerator(Class<?> scope, BeanPropertyWriter prop)
    {
        super(scope);
        _property = prop;
    }

    /**
     * We must override this method, to prevent errors when scopes are the same,
     * but underlying class (on which to access property) is different.
     */
    @Override
    public boolean canUseFor(ObjectIdGenerator<?> gen) {
        if (gen.getClass() == getClass()) {
            PropertyBasedObjectIdGenerator other = (PropertyBasedObjectIdGenerator) gen;
            if (other.getScope() == _scope) {
                /* 26-Jul-2012, tatu: This is actually not enough, because the property
                 *   accessor within BeanPropertyWriter won't work for other property fields
                 *  (see [https://github.com/FasterXML/jackson-module-jaxb-annotations/issues/9]
                 *  for details).
                 *  So we need to verify that underlying property is actually the same.
                 */
                return (other._property == _property);
            }
        }
        return false;
    }
    
    @Override
    public Object generateId(Object forPojo) {
        try {
            return _property.get(forPojo);
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new IllegalStateException("Problem accessing property '"
                    +_property.getName()+"': "+e.getMessage(), e);
        }
    }

    @Override
    public ObjectIdGenerator<Object> forScope(Class<?> scope) {
        return (scope == _scope) ? this : new PropertyBasedObjectIdGenerator(scope, _property);
    }

    @Override
    public ObjectIdGenerator<Object> newForSerialization(Object context) {
        // No state, can return this
        return this;
    }

    @Override
    public com.fasterxml.jackson.annotation.ObjectIdGenerator.IdKey key(Object key) {
        if (key == null) {
            return null;
        }
        // should we use general type for all; or type of property itself?
        return new IdKey(getClass(), _scope, key);
    }

}

⏎ com/fasterxml/jackson/databind/ser/impl/PropertyBasedObjectIdGenerator.java

 

⇒ Jackson Dataformat Extensions

⇐ Jackson Data Binding Source Code

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library