过滤类
1
/** *//**
2
*
3 *
4 * apache 出的 struts hibernate 字符编码处理过滤器
5 *
6 *
7
*/
8
package com.zeroidea.common;
9/**//*
10* Copyright 2004 The Apache Software Foundation
11*
12* Licensed under the Apache License, Version 2.0 (the "License");
13* you may naot use this file except in compliance with the License.
14* You may obtain a copy of the License at
15*
16* http://www.apache.org/licenses/LICENSE-2.0
17*
18* Unless required by applicable law or agreed to in writing, software
19* distributed under the License is distributed on an "AS IS" BASIS,
20* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21* See the License for the specific language governing permissions and
22* limitations under the License.
23*/
24
25import java.io.IOException;
26
27import javax.servlet.Filter;
28import javax.servlet.FilterChain;
29import javax.servlet.FilterConfig;
30import javax.servlet.ServletException;
31import javax.servlet.ServletRequest;
32import javax.servlet.ServletResponse;
33
34
35/** *//**
36 * <p>Example filter that sets the character encoding to be used in parsing the
37 * incoming request, either unconditionally or only if the client did not
38 * specify a character encoding. Configuration of this filter is based on
39 * the following initialization parameters:</p>
40 * <ul>
41 * <li><strong>encoding</strong> - The character encoding to be configured
42 * for this request, either conditionally or unconditionally based on
43 * the <code>ignore</code> initialization parameter. This parameter
44 * is required, so there is no default.</li>
45 * <li><strong>ignore</strong> - If set to "true", any character encoding
46 * specified by the client is ignored, and the value returned by the
47 * <code>selectEncoding()</code> method is set. If set to "false,
48 * <code>selectEncoding()</code> is called <strong>only</strong> if the
49 * client has not already specified an encoding. By default, this
50 * parameter is set to "true".</li>
51 * </ul>
52 *
53 * <p>Although this filter can be used unchanged, it is also easy to
54 * subclass it and make the <code>selectEncoding()</code> method more
55 * intelligent about what encoding to choose, based on characteristics of
56 * the incoming request (such as the values of the <code>Accept-Language</code>
57 * and <code>User-Agent</code> headers, or a value stashed in the current
58 * user's session.</p>
59 *
60 * @author Craig McClanahan
61 * @version $Revision: 1.2 $ $Date: 2004/03/18 16:40:28 $
62 */
63
64public class SetCharacterEncodingFilter implements Filter 
{
65
66
67 // ----------------------------------------------------- Instance Variables
68
69
70
/** *//**
71 * The default character encoding to set for requests that pass through
72 * this filter.
73
*/
74 protected String encoding = null;
75
76 /** *//**
77 * The filter configuration object we are associated with. If this value
78 * is null, this filter instance is not currently configured.
79 *
80 * @uml.property name="filterConfig"
81 * @uml.associationEnd multiplicity="(0 1)"
82 */
83 protected FilterConfig filterConfig = null;
84
85
86
87 /** *//**
88 * Should a character encoding specified by the client be ignored?
89 */
90 protected boolean ignore = true;
91
92
93 // --------------------------------------------------------- Public Methods
94
95
96 /** *//**
97 * Take this filter out of service.
98 */
99 public void destroy() {
100
101 this.encoding = null;
102 this.filterConfig = null;
103
104 }
105
106
107 /** *//**
108 * Select and set (if specified) the character encoding to be used to
109 * interpret request parameters for this request.
110 *
111 * @param request The servlet request we are processing
112 * @param result The servlet response we are creating
113 * @param chain The filter chain we are processing
114 *
115 * @exception IOException if an input/output error occurs
116 * @exception ServletException if a servlet error occurs
117 */
118 public void doFilter(ServletRequest request, ServletResponse response,
119 FilterChain chain)
120 throws IOException, ServletException {
121
122 // Conditionally select and set the character encoding to be used
123 if (ignore || (request.getCharacterEncoding() == null)) {
124 String encoding = selectEncoding(request);
125 if (encoding != null)
126 request.setCharacterEncoding(encoding);
127 }
128
129 // Pass control on to the next filter
130 chain.doFilter(request, response);
131
132 }
133
134 /** *//**
135 * Place this filter into service.
136 *
137 * @param filterConfig The filter configuration object
138 *
139 * @uml.property name="filterConfig"
140 */
141 public void init(FilterConfig filterConfig) throws ServletException {
142
143 this.filterConfig = filterConfig;
144 this.encoding = filterConfig.getInitParameter("encoding");
145 String value = filterConfig.getInitParameter("ignore");
146 if (value == null)
147 this.ignore = true;
148 else if (value.equalsIgnoreCase("true"))
149 this.ignore = true;
150 else if (value.equalsIgnoreCase("yes"))
151 this.ignore = true;
152 else
153 this.ignore = false;
154
155 }
156
157 // ------------------------------------------------------ Protected Methods
158
159
160 /** *//**
161 * Select an appropriate character encoding to be used, based on the
162 * characteristics of the current request and/or filter initialization
163 * parameters. If no character encoding should be set, return
164 * <code>null</code>.
165 * <p>
166 * The default implementation unconditionally returns the value configured
167 * by the <strong>encoding</strong> initialization parameter for this
168 * filter.
169 *
170 * @param request The servlet request we are processing
171 */
172 protected String selectEncoding(ServletRequest request) {
173
174 return (this.encoding);
175
176 }
177
178
179}
180 web.xml 中的设置
1 <!-- 编码转换过滤器 -->
2 <filter>
3 <filter-name>Encoding</filter-name>
4 <filter-class>com.zeroidea.common.SetCharacterEncodingFilter</filter-class>
5 <init-param>
6 <param-name>encoding</param-name>
7 <param-value>GBK</param-value>
8 </init-param>
9 </filter>
10
11 <!-- 映射过滤器-->
12 <filter-mapping>
13 <filter-name>Encoding</filter-name>
14 <url-pattern>*.jsp</url-pattern>
15 </filter-mapping>
16 <filter-mapping>
17 <filter-name>Encoding</filter-name>
18 <url-pattern>*.do</url-pattern>
19 </filter-mapping>
posted on 2006-11-30 16:32
一手的小窝窝 阅读(1907)
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