1 /*
2 * Copyright 2004-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.springmodules.validation.bean.context.aop;
18
19 import org.aopalliance.intercept.MethodInterceptor;
20 import org.aopalliance.intercept.MethodInvocation;
21 import org.springmodules.validation.bean.context.ValidationContext;
22 import org.springmodules.validation.bean.context.ValidationContextHolder;
23 import org.springmodules.validation.bean.context.ValidationContextUtils;
24
25 /**
26 * A parent class to any around validation context advice that intercepts method invocations.
27 * <p/>
28 * This advice is based on {@link org.springmodules.validation.bean.context.DefaultValidationContext} and relies on
29 * the {@link #getValidationContextTokens(org.aopalliance.intercept.MethodInvocation)} implementation to supply the
30 * appropiate context.
31 *
32 * @author Uri Boness
33 */
34 public abstract class AbstractValidationContextInterceptor implements MethodInterceptor {
35
36 private boolean extendExistingContext = false;
37
38 public Object invoke(MethodInvocation methodInvocation) throws Throwable {
39
40 String[] contextTokens = getValidationContextTokens(methodInvocation);
41
42 ValidationContext originalContext = ValidationContextHolder.getValidationContext();
43 if (originalContext != null && extendExistingContext) {
44 ValidationContextUtils.extendContext(contextTokens);
45 } else {
46 ValidationContextUtils.setContext(contextTokens);
47 }
48
49 Object result = methodInvocation.proceed();
50
51 // setting the validation context back to the original one (the one that was set before this advice was called)
52 if (originalContext != null) {
53 ValidationContextHolder.setValidationContext(originalContext);
54 } else {
55 ValidationContextUtils.clearContext();
56 }
57
58 return result;
59
60 }
61
62 /**
63 * Will be implemented by all subclasses to determine what validation context tokens will be supported by the
64 * validation context associated with the given method invocation.
65 *
66 * @param methodInvocation The given method invocation.
67 * @return The tokens supported by the validation context associated with the given method invocation.
68 */
69 protected abstract String[] getValidationContextTokens(MethodInvocation methodInvocation);
70
71
72 //============================================== Setter/Getter =====================================================
73
74 /**
75 * Determines whether this interceptor should extend the already exsiting context (if one already exists). If so,
76 * the tokens returned by {@link #getValidationContextTokens(org.aopalliance.intercept.MethodInvocation)} will be
77 * supported along with all tokens supported by the already existing validation context.
78 * <p/>
79 * By default this advice does <b>not</b> extend the already existing context, instead it creates and sets a new one.
80 *
81 * @param extendExistingContext Determines whether this interceptor should extend the already exsiting context
82 * (if one already exists).
83 */
84 public void setExtendExistingContext(boolean extendExistingContext) {
85 this.extendExistingContext = extendExistingContext;
86 }
87 }