统一全站字符集编码

 通过配置参数charset指明使用何种字符编码,以处理Html Form请求参数的中文问题

1 package me.gacl.web.filter;
 2 
 3 import java.io.IOException;
 4 import javax.servlet.Filter;
 5 import javax.servlet.FilterChain;
 6 import javax.servlet.FilterConfig;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.ServletRequest;
 9 import javax.servlet.ServletResponse;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletRequestWrapper;
12 import javax.servlet.http.HttpServletResponse;
13 
14 /**
15 * @ClassName: CharacterEncodingFilter
16 * @Description: 此过滤器用来解决全站中文乱码问题
17 * @author: 孤傲苍狼
18 * @date: 2014-8-31 下午11:09:37
19 *
20 */ 
21 public class CharacterEncodingFilter implements Filter {
22 
23     private FilterConfig filterConfig = null;
24     //设置默认的字符编码
25     private String defaultCharset = "UTF-8";
26 
27     public void doFilter(ServletRequest req, ServletResponse resp,
28             FilterChain chain) throws IOException, ServletException {
29         
30         HttpServletRequest request = (HttpServletRequest) req;
31         HttpServletResponse response = (HttpServletResponse) resp;
32         String charset = filterConfig.getInitParameter("charset");
33         if(charset==null){
34             charset = defaultCharset;
35         }
36         request.setCharacterEncoding(charset);
37         response.setCharacterEncoding(charset);
38         response.setContentType("text/html;charset="+charset);
39         
40         MyCharacterEncodingRequest requestWrapper = new MyCharacterEncodingRequest(request);
41         chain.doFilter(requestWrapper, response);
42     }
43 
44     public void init(FilterConfig filterConfig) throws ServletException {
45         //得到过滤器的初始化配置信息
46         this.filterConfig = filterConfig;
47     }
48     
49     public void destroy() {
50 
51     }
52 }
53 
54 /*
55 1.实现与被增强对象相同的接口 
56 2、定义一个变量记住被增强对象
57 3、定义一个构造器，接收被增强对象
58 4、覆盖需要增强的方法
59 5、对于不想增强的方法，直接调用被增强对象（目标对象）的方法
60  */
61  
62 class MyCharacterEncodingRequest extends HttpServletRequestWrapper{
63     
64     private HttpServletRequest request;
65     public MyCharacterEncodingRequest(HttpServletRequest request) {
66         super(request);
67         this.request = request;
68     }
69     /* 重写getParameter方法
70      * @see javax.servlet.ServletRequestWrapper#getParameter(java.lang.String)
71      */
72     @Override
73     public String getParameter(String name) {
74         
75         try{
76             //获取参数的值
77             String value= this.request.getParameter(name);
78             if(value==null){
79                 return null;
80             }
81             //如果不是以get方式提交数据的，就直接返回获取到的值
82             if(!this.request.getMethod().equalsIgnoreCase("get")) {
83                 return value;
84             }else{
85                 //如果是以get方式提交数据的，就对获取到的值进行转码处理
86                 value = new String(value.getBytes("ISO8859-1"),this.request.getCharacterEncoding());
87                 return value;
88             }
89         }catch (Exception e) {
90             throw new RuntimeException(e);
91         }
92     }
93 }

web.xml

1  <filter>
 2       <filter-name>CharacterEncodingFilter</filter-name>
 3       <filter-class>me.gacl.web.filter.CharacterEncodingFilter</filter-class>
 4       <init-param>
 5           <param-name>charset</param-name>
 6           <param-value>UTF-8</param-value>
 7       </init-param>
 8   </filter>
 9   
10   <filter-mapping>
11       <filter-name>CharacterEncodingFilter</filter-name>
12       <url-pattern>/*</url-pattern>
13   </filter-mapping>

文章来源：https://www.cnblogs.com/xdp-gacl/p/3948422.html