java字符编码过滤器EncodingFilter

package com.lzcc.mvc.web.filter;

import java.io.IOException; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry;

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.annotation.WebFilter; import javax.servlet.annotation.WebInitParam; import javax.servlet.http.HttpServletRequest; @WebFilter(filterName="encodingFilter",urlPatterns="/*",initParams={@WebInitParam(description="字符编码",name="charSet",value="UTF-8")}) public class EncodingFilter implements Filter{

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

 @Override  public void doFilter(ServletRequest req, ServletResponse resp,    FilterChain chain) throws IOException, ServletException {   // TODO Auto-generated method stub      HttpServletRequest request = (HttpServletRequest)req;      // 判断用户的请求类型   if(request.getMethod().equalsIgnoreCase("POST")){// 如果请求是POST    req.setCharacterEncoding(this.charSet);// 设置统一编码   }else{// get请求        Map<String, String[]> maps = req.getParameterMap();        Iterator<Entry<String, String[]>> iter =  maps.entrySet().iterator();        while(iter.hasNext()){          Entry<String, String[]> map = iter.next();          String[] values = map.getValue();          for (int i = 0; i < values.length; i++) {      values[i] = new String(values[i].getBytes("ISO-8859-1"), this.charSet);     }    }       }      chain.doFilter(req, resp);// 将请求继续传递  }

 @Override  public void init(FilterConfig config) throws ServletException {   // TODO Auto-generated method stub   this.charSet = config.getInitParameter("charSet");  }   }