关于乱码的产生以及怎样解决乱码请看我的博客字节乱码, 字符乱码,表单提交get&post乱码
这里主要使用一个过滤器能够解决上述的全部乱码：
1.过滤乱码的过滤器：
package cn.itheima.filter;
import java.io.IOException;
import java.util.Map;
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.HttpServletRequestWrapper;
public class EncodingFilter implements Filter {
private FilterConfig config = null;
private String encode = null;
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
response.setContentType("text/html;charset="+encode); //--解决响应乱码
chain.doFilter(new MyHttpServletRequest((HttpServletRequest) request), response);//--包装改造request中和获取请求參数相关的方法解决请求參数乱码
}
public void init(FilterConfig filterConfig) throws ServletException {
this.config = filterConfig;
encode = config.getInitParameter("encode") == null
?"utf-8"
:config.getInitParameter("encode");
}
class MyHttpServletRequest extends HttpServletRequestWrapper{
private HttpServletRequest request = null;
private boolean isNotEncode = true;
public MyHttpServletRequest(HttpServletRequest request) {
super(request);
this.request = request;
}
@Override
public Map getParameterMap() {
try{
if(request.getMethod().equalsIgnoreCase("POST")){//--假设是post提交,一行代码解决post提交请求參数乱码
request.setCharacterEncoding(encode);
return request.getParameterMap();
}else if(request.getMethod().equalsIgnoreCase("GET")){//--假设是get提交,则应该手动编解码解决乱码
Map<String,String[]> map = request.getParameterMap();//获取有乱码的map
if(isNotEncode){//仅仅能在第一次解决乱码
for(Map.Entry<String, String[]> entry : map.entrySet()){//遍历map,解决全部值的乱码
String [] vs = entry.getValue();
for(int i=0;i<vs.length;i++){
vs[i] = new String(vs[i].getBytes("iso8859-1"),encode);
}
}
isNotEncode = false;//设置为false,第二次就不会再进这个代码块了
}
return map;
}else{
return request.getParameterMap();
}
}catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
@Override
public String[] getParameterValues(String name) {
return (String[]) getParameterMap().get(name);
}
@Override
public String getParameter(String name) {
return getParameterValues(name) == null ? null : getParameterValues(name)[0];
}
}
}
2.web.xml的配置：
<filter> <filter-name>EncodingFilter</filter-name> <filter-class>cn.itheima.filter.EncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>EncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>3.jsp測试乱码：分别包含get和post提交
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<h1>post提交</h1>
<form action="${pageContext.request.contextPath }/servlet/FilterDemo1" method="post">
姓名：<input type="text" name="name"/><br>
地址：<input type="text" name="addr"/><br>
<input type="submit" value="提交"/><br>
</form>
<h1>get提交</h1>
<form action="${pageContext.request.contextPath }/servlet/FilterDemo1" method="get">
姓名：<input type="text" name="name"/><br>
地址：<input type="text" name="addr"/><br>
<input type="submit" value="提交"/><br>
</form>
</body>
</html>
4.jsp提交后转向的页面：
package cn.itheima.servlet;
import java.io.IOException;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FilterDemo1 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.getWriter().write("你好！过滤器！我没有乱码！
");
String name = request.getParameter("name");
String addr = request.getParameter("addr");
System.out.println(name);
System.out.println(addr);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
结果分析：
