Immutable.java

package org.solmix.commons.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/*
 * Copyright (c) 2005 Brian Goetz and Tim Peierls
 * Released under the Creative Commons Attribution License
 *   (http://creativecommons.org/licenses/by/2.5)
 * Official home: http://www.jcip.net
 *
 * Any republication or derived work distributed in source code form
 * must include this copyright and license notice.
 */


/**
 * The class to which this annotation is applied is immutable.  This means that
 * its state cannot be seen to change by callers, which implies that
 * <ul>
 * <li> all public fields are final, </li>
 * <li> all public final reference fields refer to other immutable objects, and </li>
 * <li> constructors and methods do not publish references to any internal state
 *      which is potentially mutable by the implementation. </li>
 * </ul>
 * Immutable objects may still have internal mutable state for purposes of performance
 * optimization; some state variables may be lazily computed, so long as they are computed
 * from immutable state and that callers cannot tell the difference.
 * <p>
 * Immutable objects are inherently thread-safe; they may be passed between threads or
 * published without synchronization.
 */
@Documented
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Immutable {
}