01: /*
02: * Copyright 2002-2007 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.springframework.aop;
18:
19: import java.lang.reflect.Method;
20:
21: /**
22: * Part of a {@link Pointcut}: Checks whether the target method is eligible for advice.
23: *
24: * <p>A MethodMatcher may be evaluated <b>statically</b> or at <b>runtime</b> (dynamically).
25: * Static matching involves method and (possibly) method attributes. Dynamic matching
26: * also makes arguments for a particular call available, and any effects of running
27: * previous advice applying to the joinpoint.
28: *
29: * <p>If an implementation returns <code>false</code> from its {@link #isRuntime()}
30: * method, evaluation can be performed statically, and the result will be the same
31: * for all invocations of this method, whatever their arguments. This means that
32: * if the {@link #isRuntime()} method returns <code>false</code>, the 3-arg
33: * {@link #matches(java.lang.reflect.Method, Class, Object[])} method will never be invoked.
34: *
35: * <p>If an implementation returns <code>true</code> from its 2-arg
36: * {@link #matches(java.lang.reflect.Method, Class)} method and its {@link #isRuntime()} method
37: * returns <code>true</code>, the 3-arg {@link #matches(java.lang.reflect.Method, Class, Object[])}
38: * method will be invoked <i>immediately before each potential execution of the related advice</i>,
39: * to decide whether the advice should run. All previous advice, such as earlier interceptors
40: * in an interceptor chain, will have run, so any state changes they have produced in
41: * parameters or ThreadLocal state will be available at the time of evaluation.
42: *
43: * @author Rod Johnson
44: * @since 11.11.2003
45: * @see Pointcut
46: * @see ClassFilter
47: */
48: public interface MethodMatcher {
49:
50: /**
51: * Perform static checking whether the given method matches. If this
52: * returns <code>false</code> or if the {@link #isRuntime()} method
53: * returns <code>false</code>, no runtime check (i.e. no.
54: * {@link #matches(java.lang.reflect.Method, Class, Object[])} call) will be made.
55: * @param method the candidate method
56: * @param targetClass the target class (may be <code>null</code>, in which case
57: * the candidate class must be taken to be the method's declaring class)
58: * @return whether or not this method matches statically
59: */
60: boolean matches(Method method, Class targetClass);
61:
62: /**
63: * Is this MethodMatcher dynamic, that is, must a final call be made on the
64: * {@link #matches(java.lang.reflect.Method, Class, Object[])} method at
65: * runtime even if the 2-arg matches method returns <code>true</code>?
66: * <p>Can be invoked when an AOP proxy is created, and need not be invoked
67: * again before each method invocation,
68: * @return whether or not a runtime match via the 3-arg
69: * {@link #matches(java.lang.reflect.Method, Class, Object[])} method
70: * is required if static matching passed
71: */
72: boolean isRuntime();
73:
74: /**
75: * Check whether there a runtime (dynamic) match for this method,
76: * which must have matched statically.
77: * <p>This method is invoked only if the 2-arg matches method returns
78: * <code>true</code> for the given method and target class, and if the
79: * {@link #isRuntime()} method returns <code>true</code>. Invoked
80: * immediately before potential running of the advice, after any
81: * advice earlier in the advice chain has run.
82: * @param method the candidate method
83: * @param targetClass the target class (may be <code>null</code>, in which case
84: * the candidate class must be taken to be the method's declaring class)
85: * @param args arguments to the method
86: * @return whether there's a runtime match
87: * @see MethodMatcher#matches(Method, Class)
88: */
89: boolean matches(Method method, Class targetClass, Object[] args);
90:
91: /**
92: * Canonical instance that matches all methods.
93: */
94: MethodMatcher TRUE = TrueMethodMatcher.INSTANCE;
95:
96: }
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