过滤器（防止乱码）

 1 package cqvie.yjq.filter;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.Filter;
 6 import javax.servlet.FilterChain;
 7 import javax.servlet.FilterConfig;
 8 import javax.servlet.ServletException;
 9 import javax.servlet.ServletRequest;
10 import javax.servlet.ServletResponse;
11 import javax.servlet.http.HttpServletRequest;
12 import javax.servlet.http.HttpServletResponse;
13 
14 public class EncodingFilter1 implements Filter {
15 
16     public void destroy() {
17 
18     }
19 
20     public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain chain)
21             throws IOException, ServletException {
22 
23         //1.首先ServletRequest转换为HttpServletRequest
24         HttpServletRequest request = (HttpServletRequest) arg0;
25         //2.把ServletResponse转换为HttpServletResponse
26         HttpServletResponse response = (HttpServletResponse) arg1;
27         //3.得到当前的请求方式
28         String method = request.getMethod();
29         //4.判断
30         if(method.toUpperCase().equals("POST")) {
31             //是post请求时，处理乱码
32             request.setCharacterEncoding("UTF-8");
33             //放行
34             chain.doFilter(request, response);
35         } else {
36             chain.doFilter(request, response);
37         }
38     }
39 
40     public void init(FilterConfig arg0) throws ServletException {
41 
42     }
43 
44 }