[編碼] Tomcat / Struts2 解決中文亂碼問題

=== Tomcat 的編碼問題 ===

Tomcat 的 server.xml ( 位於 conf 目錄下)

 

【Get 請求部份】

找出

<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />

修改為

<Connector port="8080" protocol="HTTP/1.1"
 URIEncoding="UTF-8"
connectionTimeout="20000"
redirectPort="8443" />

【Post 請求部份】

Tomcat 6.x 使用 SetCharacterEncodingFilter 這個 Filter

將 webapps/examples/WEB-INF/classes/filters/SetCharacterEncodingFilter.class
複製到你的webapp資料夾中
yourwebapp/WEB-INF/classes/filters/SetCharacterEncodingFilter.class
並在web.xml設定filter
<filter>
<filter-name>Set Character Encoding</filter-name>
<filter-class>filters.SetCharacterEncodingFilter</filter-class>
<init-param>
  <param-name>encoding</param-name>
  <param-value>UTF-8</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<!--將全部的請求都mapping給filter-->
<url-pattern>/*</url-pattern>
</filter-mapping>

Tomcat 7.x以及5.5.36、6.0.36之後的版本

在Tomcat 7.x以及5.5.36、6.0.36之後的版本中，已經將SetCharacterEncodingFilter加入Tomcat核心中，因此不需要再自行複製class到自己的webapp資料夾中，在設定filter時直接指定class即可。
<filter>
<filter-name>Set_Character_Encoding</filter-name>
<!--差異處-->
<filter-class>org.apache.catalina.filters.SetCharacterEncodingFilter</filter-class>
<init-param>
  <param-name>encoding</param-name>
  <param-value>UTF-8</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>Set_Character_Encoding</filter-name>
<!--將全部的請求都mapping給filter-->
<url-pattern>/*</url-pattern>
</filter-mapping>

Maven dependency 依照所使用的 Tomcat 版本而設定

<properties>
  <tomcat-catalina.version>7.0.41</tomcat-catalina.version>
</properties>
<dependency>
  <groupId>org.apache.tomcat</groupId>
  <artifactId>tomcat-catalina</artifactId>
  <version>${tomcat-catalina.version}</version>
  <scope>provided</scope>
</dependency>

=== Struts2 的編碼問題 ===

action 接收中文參數亂碼解決方法

首先確定 struts.xml 配置檔是否設定好

<constant name="struts.locale" value="zh_TW"/>
<!-- 定義系統預設編碼集 -->
<constant name="struts.i18n.encoding" value="UTF-8"/>

【針對 post 部分】

設置 編碼過濾器

package org.filter;

import java.io.IOException;
import java.net.URLDecoder;
 
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
public class CharsetEncodingFilter implements Filter {
   
    @Override  
    public void doFilter(ServletRequest sRequest, ServletResponse sResponse,  
            FilterChain filterChain) throws IOException, ServletException  
    {  
        HttpServletRequest request = (HttpServletRequest) sRequest;  
        HttpServletResponse response = (HttpServletResponse) sResponse;  
        // 設置編碼集  
        request.setCharacterEncoding("utf-8");  
        response.setCharacterEncoding("utf-8");  
        filterChain.doFilter(request, response);  
    }

    @Override
    public void destroy() {
        // TODO Auto-generated method stub
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
        // TODO Auto-generated method stub
    }  
}

接著將其加入到 Web.xml 中以便生效

<!-- 過濾所有的請求 編碼為 utf-8，需寫在 struts2 filter 之前 -->
<filter>
  <filter-name>CharsetEncodingFilter</filter-name>
  <filter-class>org.filter.CharsetEncodingFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>CharsetEncodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
    <filter-name>struts2</filter-name>
    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

【針對 get 部分】

如 http:///xxx?name=威廉

由parameter 中取值之後，將其轉碼

String str = request.getParameter(“name”);

str = new String(str.getBytes(“ISO-8859-1”), “UTF-8”);

參照：Struts2亂碼終極解決方法