RequestAttributeRule


1   /*
2    * Copyright 2000,2004 The Apache Software Foundation.
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  package org.apache.webapp.balancer.rules;
17  
18  import javax.servlet.http.HttpServletRequest  ;
19  
20  
21  /**
22   * This rule accepts or rejects requests
23   * based on the presence of a attribute
24   * in the request.
25   *
26   * @author Yoav Shapira
27   */
28  public class RequestAttributeRule extends BaseRule {
29      /**
30       * The target attribute name (attribute
31       * must be present for match to succeed).
32       */
33      private String   attributeName;
34  
35      /**
36       * The target attribute value.  This
37       * is optional: null means any attribute
38       * value is OK for a match.  A non-null
39       * value will be matches exactly.
40       */
41      private Object   attributeValue;
42  
43      /**
44       * Sets the target attribute name.
45       *
46       * @param theAttributeName The attribute name
47       */
48      public void setAttributeName(String   theAttributeName) {
49          if (theAttributeName == null) {
50              throw new IllegalArgumentException  (
51                  "attributeName cannot be null.");
52          } else {
53              attributeName = theAttributeName;
54          }
55      }
56  
57      /**
58       * Returns the target attribute name.
59       *
60       * @return String The target attribute name.
61       */
62      protected String   getAttributeName() {
63          return attributeName;
64      }
65  
66      /**
67       * Sets the attribute value, which may be null.
68       *
69       * @param theAttributeValue The attribute value
70       */
71      public void setAttributeValue(Object   theAttributeValue) {
72          attributeValue = theAttributeValue;
73      }
74  
75      /**
76       * Returns the target attribute value,
77       * which may be null.
78       *
79       * @return Object The target attribute value
80       */
81      protected Object   getAttributeValue() {
82          return attributeValue;
83      }
84  
85      /**
86       * @see org.apache.webapp.balancer.Rule#matches(HttpServletRequest)
87       */
88      public boolean matches(HttpServletRequest   request) {
89          Object   actualAttributeValue = request.getAttribute(getAttributeName());
90  
91          if (actualAttributeValue == null) {
92              return (getAttributeValue() == null);
93          } else {
94              return (actualAttributeValue.equals(getAttributeValue()));
95          }
96      }
97  
98      /**
99       * Returns a String representation of this object.
100      *
101      * @return String
102      */
103     public String   toString() {
104         StringBuffer   buffer = new StringBuffer  ();
105 
106         buffer.append("[");
107         buffer.append(getClass().getName());
108         buffer.append(": ");
109 
110         buffer.append("Target attribute name: ");
111         buffer.append(getAttributeName());
112         buffer.append(" / ");
113 
114         buffer.append("Target attribute value: ");
115         buffer.append(getAttributeValue());
116         buffer.append(" / ");
117 
118         buffer.append("Redirect URL: ");
119         buffer.append(getRedirectUrl());
120 
121         buffer.append("]");
122 
123         return buffer.toString();
124     }
125 }
126 
127 
128 // End of file: RequestAttributeRule.java
129
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