JSP中文参数传至JavaBean出现乱码

来源：互联网发布：r语言数据按组距分组编辑：程序博客网时间：2024/06/05 14:23

[关键字]:Tomcat,GBK,GB2312,Filter,乱码,JSP,charset,Servlet

[摘要]:书上说的都能看懂，但是真正做起来却会遇到问题。解决这些问题的过程，就是上机练习的意义。以前遇到的乱码问题要么通过request.setCharacterEnconding("GB2312")解决了，要么就是new String(str.getBytes("ISO-8859-1") , "GB2312")。但是这回是JavaBean出问题了。上面的两句行不通了，只能通过设置Filter来解决。希望遇到类似问题的朋友，站在我们的肩膀上，能看的更远。

[正文]:

写了一个简单的JavaBean,用于计算加减乘除。
CalculateBean.java:

   package ch6.calcbean;
   import java.io.*;

   public class CalculateBean{
       private int operandFirst;//操作数1
       private char operator;//运算符
       private int operandSecond;//操作数2
       private double result;//运算结果

       public int getOperandFirst(){
           return this.operandFirst;
       }
       public void setOperandFirst(int op){
           this.operandFirst = op;
       }

       public char getOperator(){
           return operator;
       }
       public void setOperator(char operator){
           this.operator = operator;
       }

       public int getOperandSecond(){
           return this.operandSecond;
       }
       public void setOperandSecond(int op){
           this.operandSecond = op;
       }

       public double getResult(){
           return this.result;
       }
       public void setResult(double result){
           this.result = result;
       }

       public void calculate(){
           double temp;
           switch(operator){
               case '+':
                   temp = getOperandFirst() + getOperandSecond();
                   break;
               case '-':
                   temp = getOperandFirst() - getOperandSecond();
                   break;
               case '×':
                   temp = getOperandFirst() * getOperandSecond();
                   break;
               case '÷':
                   temp = 1.0 * getOperandFirst() / getOperandSecond();
                   break;
               default:
                   temp = 0;
           }

           setResult(temp);
       }
   }

由Calculate.jsp调用CalculateBean完成计算:
Calculate.jsp:

<%@page contentType="text/html;charset=GB2312" pageEncoding="GB2312"%>
   <html>
   <head>
   <meta http-equiv="Content-Type" content="text/html;charset=gb2312">
   </head>
   </body>
   <form method="post" action="Calculate.jsp">
       <input type="hidden" name="action" value="TRUE"/>
       第一个操作数:
       <input type="text" name="operandFirst" />
       运算符:
       <select name = "operator" >
           <option value="+">+
           <option value="-">-
           <option value="×">×
           <option value="÷">÷
       </select>
       第二个操作数:
       <input type="text" name="operandSecond" />
       <input type="submit" value="提交"/>
   </form>

   <%if(request.getParameter("action")!=null){ %>

       <jsp:useBean id="calcu" class="ch6.calcbean.CalculateBean" scope="request"/>
       <jsp:setProperty name="calcu" property="*"/>
       <%   calcu.calculate(); %>
       <jsp:getProperty name="calcu" property="operandFirst"/>
       <jsp:getProperty name="calcu" property="operator"/>
       <jsp:getProperty name="calcu" property="operandSecond"/>
       =<jsp:getProperty name="calcu" property="result"/>

   <%}%>

   </body>
   </html>

    为了完成JavaBean的调用，需将编译生成的CalculateBean.class部署到WEB-INF/classes/ch6目录下。然后运行Calculate.jsp即可以看到结果。程序没有什么问题。但是运行结果总是不对，输出的运算结果result总是为0。怀疑<jsp:setProperty name="calcu" property="*"/> 有问题。也怀疑过<%   calcu.calculate(); %> 是否执行到、、、总之，怎么调试也不正确。后来，再仔细看看书，找到了解决办法:"JavaBean部署完成之后，要重启Tomcat"。就这么简单！当然，我没有使用IDE，是手工编译部署的，如果使用IDE，也许就没这问题了。

    一个问题解决了，另一个问题又来了。算加减时，没有问题。算乘除时，JavaBean并不能正确地接收"×"、"÷"。因为"×"、"÷"并不是标准的ASCII字符。在jsp/servlet中直接用request.setCharactorEncoding("gb2312")就可以了。但是这是在JavaBean中，而且用<jsp:setProperty name="calcu" property="*"/>也没办法设置Encoding。这回到网上搜，有人说应该加上<%@page contentType="text/html;charset=GB2312" pageEncoding="GB2312"%>，还有人说用new String(str.getBytes("ISO-8859-1") , "GB2312")，还有server.xml中加上URIEncoding="GB2312"(<Connector ......   port="8080" redirectPort="8443" URIEncoding="GB2312" >)。这些都没能解决问题。

    最后，找到了答案。关于乱码，Skytiger讲述的比较清楚。步骤如下(我用的是JDK1.6/Tomcat6.0，所以对Skytiger的讲述稍作修改):
    1、实现一个Filter，设置处理字符集为GB2312。(Tomcat下Tomcat/webapps/examples/WEB-INF/classes/filters有完整的例子，请参考web.xml和SetCharacterEncodingFilter的配置。)
    a、只要把Tomcat/webapps/examples/WEB-INF/classes/filters /SetCharacterEncodingFilter.class文件拷到你的/WEB-INF/classes/filters下，如果没有filters目录，就创建一个。
    b、在你的web.xml里加入如下几行:

   <filter>
       <filter-name>Set Character Encoding</filter-name>
       <filter-class>filters.SetCharacterEncodingFilter</filter-class>
       <init-param>
            <param-name>encoding</param-name>
            <param-value>GB2312</param-value>
       </init-param>
   </filter>
   <filter-mapping>
       <filter-name>Set Character Encoding</filter-name>
       <url-pattern>/*</url-pattern>
   </filter-mapping>

    2、打开tomcat的Tomcat/conf/server.xml文件，加入URIEncodeing="GB2312"，完整的如下:
    <Connector port="8080" protocol="HTTP/1.1"
               maxThreads="150" connectionTimeout="20000"
               redirectPort="8443" URIEncodeing="GB2312"/>

    3、别忘了重启Tomcat。

    这样改完，再运行就正确了。

    致谢:
        多谢Skytiger。但是关于Skytiger的内容，是在archaic的blog上找到的(archaic也遇到了类似的问题)，在此一并致谢。

    正文内容到此结束。
    ==============================
    ==============================
    ==============================
    ==============================
    为了方便大家，再附上SetCharacterEncodingFilter.java 和 archaic原文。

    ==============================
    SetCharacterEncodingFilter.java:
    ==============================

   /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */

   package filters;

   import java.io.IOException;
   import javax.servlet.Filter;
   import javax.servlet.FilterChain;
   import javax.servlet.FilterConfig;
   import javax.servlet.ServletException;
   import javax.servlet.ServletRequest;
   import javax.servlet.ServletResponse;

   /**
   * <p>Example filter that sets the character encoding to be used in parsing the
   * incoming request, either unconditionally or only if the client did not
   * specify a character encoding. Configuration of this filter is based on
   * the following initialization parameters:</p>
   * <ul>
   * <li><strong>encoding</strong> - The character encoding to be configured
   *     for this request, either conditionally or unconditionally based on
   *     the <code>ignore</code> initialization parameter. This parameter
   *     is required, so there is no default.</li>
   * <li><strong>ignore</strong> - If set to "true", any character encoding
   *     specified by the client is ignored, and the value returned by the
   *     <code>selectEncoding()</code> method is set. If set to "false,
   *     <code>selectEncoding()</code> is called <strong>only</strong> if the
   *     client has not already specified an encoding. By default, this
   *     parameter is set to "true".</li>
   * </ul>
   *
   * <p>Although this filter can be used unchanged, it is also easy to
   * subclass it and make the <code>selectEncoding()</code> method more
   * intelligent about what encoding to choose, based on characteristics of
   * the incoming request (such as the values of the <code>Accept-Language</code>
   * and <code>User-Agent</code> headers, or a value stashed in the current
   * user's session.</p>
   *
   * @author Craig McClanahan
   * @version $Revision: 500674 $ $Date: 2007-01-28 00:15:00 +0100 (dim., 28 janv. 2007) $
   */

   public class SetCharacterEncodingFilter implements Filter {

        // ----------------------------------------------------- Instance Variables

        /**
         * The default character encoding to set for requests that pass through
         * this filter.
         */
        protected String encoding = null;

        /**
         * The filter configuration object we are associated with. If this value
         * is null, this filter instance is not currently configured.
         */
        protected FilterConfig filterConfig = null;

        /**
         * Should a character encoding specified by the client be ignored?
         */
        protected boolean ignore = true;

        // --------------------------------------------------------- Public Methods

        /**
         * Take this filter out of service.
         */
        public void destroy() {

       this.encoding = null;
       this.filterConfig = null;

        }

        /**
         * Select and set (if specified) the character encoding to be used to
         * interpret request parameters for this request.
         *
         * @param request The servlet request we are processing
         * @param result The servlet response we are creating
         * @param chain The filter chain we are processing
         *
         * @exception IOException if an input/output error occurs
         * @exception ServletException if a servlet error occurs
         */
        public void doFilter(ServletRequest request, ServletResponse response,
               FilterChain chain)
       throws IOException, ServletException {

       // Conditionally select and set the character encoding to be used
       if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
           request.setCharacterEncoding(encoding);
       }

       // Pass control on to the next filter
       chain.doFilter(request, response);

        }

        /**
         * Place this filter into service.
         *
         * @param filterConfig The filter configuration object
         */
        public void init(FilterConfig filterConfig) throws ServletException {

       this.filterConfig = filterConfig;
       this.encoding = filterConfig.getInitParameter("encoding");
       String value = filterConfig.getInitParameter("ignore");
       if (value == null)
            this.ignore = true;
       else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
       else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
       else
            this.ignore = false;

        }

        // ------------------------------------------------------ Protected Methods

        /**
         * Select an appropriate character encoding to be used, based on the
         * characteristics of the current request and/or filter initialization
         * parameters. If no character encoding should be set, return
         * <code>null</code>.
         * <p>
         * The default implementation unconditionally returns the value configured
         * by the <strong>encoding</strong> initialization parameter for this
         * filter.
         *
         * @param request The servlet request we are processing
         */
        protected String selectEncoding(ServletRequest request) {

       return (this.encoding);

        }
   }

    ==============================
    archaic原文如下:http://archaic.blog.hexun.com/5576058_d.html
    ==============================

    JSP 页面传中文到javaBean中出现乱码 [原创 2006.09.12 14:51:31]
    刚接触JSP..乱码让我头疼了好几天.看了好多贴子.,都没搞对..

在JSP页面中

<%@page contentType="text/html;charset=GBK" language="java"%>

在server.xml文件中加入URIEncoding="GBK"

<Connector ......   port="8080" redirectPort="8443" URIEncoding="GBK" >

        在eclips中编辑好的jsp在publish后竟然不能更新到tomcat v5.0 server运行目录下..百思不得其解.我现在只好编辑完后再另存一次..

郁闷了...~!

关于乱码..Skytiger讲述的比较清楚

·jsp中文乱码问题     -|Skytiger 发表于 2006-3-17 15:56:00
　在tomcat5中发现了以前处理tomcat4的方法不能适用于处理直接通过url提交的请求，上网找资料终于发现了最完美的解决办法，不用每个地方都转换了，而且无论get,和post都正常。写了个文档，贴出来希望跟我有同样问题的人不再像我一样痛苦一次:-)

　　问题描述：

　　1 表单提交的数据，用request.getParameter(“xxx”)返回的字符串为乱码或者？？
　　2 直接通过url如http://localhost/a.jsp?name=中国，这样的get请求在服务端用request. getParameter(“name”)时返回的是乱码；按tomcat4的做法设置Filter也没有用或者用request.setCharacterEncoding("GBK");也不管用

　　原因：

　　1 tomcat的j2ee实现对表单提交即post方式提示时处理参数采用缺省的iso-8859-1来处理
　　2 tomcat对get方式提交的请求对query-string 处理时采用了和post方法不一样的处理方式。(与tomcat4不一样,所以设置setCharacterEncoding(“gbk”))不起作用。

　　解决办法：

　　首先所有的jsp文件都加上:

　　1 实现一个Filter.设置处理字符集为GBK。(在tomcat的webapps/servlet-examples目录有一个完整的例子。请参考web.xml和SetCharacterEncodingFilter的配置。)

　　1)只要把%TOMCAT安装目录%/ webapps/servlets-examples/WEB-INF/classes/filters /SetCharacterEncodingFilter.class文件拷到你的webapp目录/filters下，如果没有filters目录，就创建一个。
　　2)在你的web.xml里加入如下几行：

    <filter>
        <filter-name>Set Character Encoding</filter-name>
        <filter-class>filters.SetCharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>GBK</param-value>
        </init-param>
    </filter>
        <filter-mapping>
        <filter-name>Set Character Encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

　　3)完成.

　　2 get方式的解决办法

　　1) 打开tomcat的server.xml文件，找到区块，加入如下一行：URIEncoding=”GBK”

　　完整的应如下：

　　<Connector port="80" maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               debug="0" connectionTimeout="20000"
               disableUploadTimeout="true"
               URIEncoding="GBK"/>

　　2)重启tomcat,一切OK。

0 0