/*
* Copyright 2002-2007 the original author or authors.
*
* 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 org.springframework.aop;
import java.lang.reflect.Method;
/**
* Part of a {@link Pointcut}: Checks whether the target method is eligible for advice.
*
* <p>A MethodMatcher may be evaluated <b>statically</b> or at <b>runtime</b> (dynamically).
* Static matching involves method and (possibly) method attributes. Dynamic matching
* also makes arguments for a particular call available, and any effects of running
* previous advice applying to the joinpoint.
*
* <p>If an implementation returns <code>false</code> from its {@link #isRuntime()}
* method, evaluation can be performed statically, and the result will be the same
* for all invocations of this method, whatever their arguments. This means that
* if the {@link #isRuntime()} method returns <code>false</code>, the 3-arg
* {@link #matches(java.lang.reflect.Method, Class, Object[])} method will never be invoked.
*
* <p>If an implementation returns <code>true</code> from its 2-arg
* {@link #matches(java.lang.reflect.Method, Class)} method and its {@link #isRuntime()} method
* returns <code>true</code>, the 3-arg {@link #matches(java.lang.reflect.Method, Class, Object[])}
* method will be invoked <i>immediately before each potential execution of the related advice</i>,
* to decide whether the advice should run. All previous advice, such as earlier interceptors
* in an interceptor chain, will have run, so any state changes they have produced in
* parameters or ThreadLocal state will be available at the time of evaluation.
*
* @author Rod Johnson
* @since 11.11.2003
* @see Pointcut
* @see ClassFilter
*/
public interface MethodMatcher {
/**
* Perform static checking whether the given method matches. If this
* returns <code>false</code> or if the {@link #isRuntime()} method
* returns <code>false</code>, no runtime check (i.e. no.
* {@link #matches(java.lang.reflect.Method, Class, Object[])} call) will be made.
* @param method the candidate method
* @param targetClass the target class (may be <code>null</code>, in which case
* the candidate class must be taken to be the method's declaring class)
* @return whether or not this method matches statically
*/
boolean matches(Method method, Class targetClass);
/**
* Is this MethodMatcher dynamic, that is, must a final call be made on the
* {@link #matches(java.lang.reflect.Method, Class, Object[])} method at
* runtime even if the 2-arg matches method returns <code>true</code>?
* <p>Can be invoked when an AOP proxy is created, and need not be invoked
* again before each method invocation,
* @return whether or not a runtime match via the 3-arg
* {@link #matches(java.lang.reflect.Method, Class, Object[])} method
* is required if static matching passed
*/
boolean isRuntime();
/**
* Check whether there a runtime (dynamic) match for this method,
* which must have matched statically.
* <p>This method is invoked only if the 2-arg matches method returns
* <code>true</code> for the given method and target class, and if the
* {@link #isRuntime()} method returns <code>true</code>. Invoked
* immediately before potential running of the advice, after any
* advice earlier in the advice chain has run.
* @param method the candidate method
* @param targetClass the target class (may be <code>null</code>, in which case
* the candidate class must be taken to be the method's declaring class)
* @param args arguments to the method
* @return whether there's a runtime match
* @see MethodMatcher#matches(Method, Class)
*/
boolean matches(Method method, Class targetClass, Object[] args);
/**
* Canonical instance that matches all methods.
*/
MethodMatcher TRUE = TrueMethodMatcher.INSTANCE;
}