001 package groovy.lang;
002
003 /**
004 * Implementers of this interface can be registered in the ProxyMetaClass for
005 * notifications about method calls for objects managed by the ProxyMetaClass.
006 * See groovy/lang/InterceptorTest.groovy for details.
007 * @author Dierk Koenig
008 */
009 public interface Interceptor {
010 /**
011 * This code is executed before the method is optionally called.
012 * @param object receiver object for the method call
013 * @param methodName name of the method to call
014 * @param arguments arguments to the method call
015 * @return any arbitrary result that replaces the result of the
016 * original method call only if doInvoke() returns false and afterInvoke()
017 * relays this result.
018 */
019 Object beforeInvoke(Object object, String methodName, Object[] arguments);
020 /**
021 * This code is executed after the method is optionally called.
022 * @param object receiver object for the called method
023 * @param methodName name of the called method
024 * @param arguments arguments to the called method
025 * @param result result of the executed method call or result of beforeInvoke if method was not called
026 * @return any arbitrary result that can replace the result of the
027 * original method call. Typically, the result parameter is returned.
028 */
029 Object afterInvoke(Object object, String methodName, Object[] arguments, Object result);
030 /**
031 * @return whether the target method should be invoked at all.
032 */
033 boolean doInvoke();
034 }