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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.proxy2.interceptor;
19  
20  import org.apache.commons.proxy2.Interceptor;
21  import org.apache.commons.proxy2.Invoker;
22  import org.apache.commons.proxy2.ObjectProvider;
23  import org.apache.commons.proxy2.provider.ObjectProviderUtils;
24  
25  public final class InterceptorUtils
26  {
27      //******************************************************************************************************************
28      // Static Methods
29      //******************************************************************************************************************
30  
31      /**
32       * Creates an {@link Interceptor} which always returns a constant value (for all methods).
33       * 
34       * @param value
35       *            the constant
36       * @return an {@link Interceptor} which always returns a constant value (for all methods)
37       */
38      public static Interceptor constant(Object value)
39      {
40          return new ObjectProviderInterceptor(ObjectProviderUtils.constant(value));
41      }
42  
43      /**
44       * Creates an {@link Interceptor} which returns the resulting object from an object provider (for all methods).
45       * 
46       * @param provider
47       *            the object provider
48       * @return an {@link Interceptor} which returns the resulting object from an object provider (for all methods)
49       */
50      public static Interceptor provider(ObjectProvider<?> provider)
51      {
52          return new ObjectProviderInterceptor(provider);
53      }
54  
55      /**
56       * Creates an {@link Interceptor} which throws a specific exception (for all methods).
57       * 
58       * @param e
59       *            the exception
60       * @return an {@link Interceptor} which throws a specific exception (for all methods)
61       */
62      public static Interceptor throwing(Exception e)
63      {
64          return new ThrowingInterceptor(ObjectProviderUtils.constant(e));
65      }
66  
67      /**
68       * Creates an {@link Interceptor} which throws the exception provided by an object provider (for all methods).
69       * 
70       * @param provider
71       *            the object provider
72       * @return an {@link Interceptor} which throws the exception provided by an object provider (for all methods)
73       */
74      public static Interceptor throwing(ObjectProvider<? extends Exception> provider)
75      {
76          return new ThrowingInterceptor(provider);
77      }
78  
79      /**
80       * Creates an {@link Interceptor} that delegates to the specified {@link Invoker}.
81       * 
82       * @param invoker
83       *            delegate
84       * @return invoker {@link Interceptor}
85       */
86      public static Interceptor invoking(Invoker invoker)
87      {
88          return new InvokerInterceptor(invoker);
89      }
90  
91      //******************************************************************************************************************
92      // Constructors
93      //******************************************************************************************************************
94  
95      private InterceptorUtils()
96      {
97      }
98  }