https://github.com/cglib/cglib/cglib: cglib is a powerful, high performance and quality Code Generation Library, It is used to extend JAVA classes and implements interfaces at runtime. 
/*
 * Copyright 2003 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.sf.cglib.core;


The GeneratorStrategyClass. By providing your own strategy you may examine or modify the generated class before it is loaded. Typically this will be accomplished by subclassing DefaultGeneratorStrategy and overriding the appropriate protected method. 
See Also:
/**
 * The <code>GeneratorStrategy</code. is responsible for taking a
 * {@link ClassGenerator} and producing a byte array containing the
 * data for the generated <code>Class</code>.  By providing your
 * own strategy you may examine or modify the generated class before
 * it is loaded. Typically this will be accomplished by subclassing
 * {@link DefaultGeneratorStrategy} and overriding the appropriate
 * protected method.
 * @see AbstractClassGenerator#setStrategy
 */
public interface GeneratorStrategy {
    
Generate the class.

Params:
Returns:a byte array containing the bits of a valid Class
/**
     * Generate the class.
     * @param cg a class generator on which you can call {@link ClassGenerator#generateClass}
     * @return a byte array containing the bits of a valid Class
     */
    byte[] generate(ClassGenerator cg) throws Exception;

    
The GeneratorStrategy in use does not currently, but may in the future, affect the caching of classes generated by AbstractClassGenerator, so this is a reminder that you should correctly implement equals and hashCode
to avoid generating too many classes.

/**
     * The <code>GeneratorStrategy</code> in use does not currently, but may
     * in the future, affect the caching of classes generated by {@link
     * AbstractClassGenerator}, so this is a reminder that you should
     * correctly implement <code>equals</code> and <code>hashCode</code>
     * to avoid generating too many classes.
     */
    boolean equals(Object o);
}