乱码详情
总结：讨论了使用GET和POST方法，控制台和JSP页面显示的问题。
最终发现：在servlet或者过滤器中添加：request.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=utf-8");
即可解决页面显示乱码问题。
JSP页面中
<%@ page language="java"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/encodingServlet" method="get"> //选择GET或者POST提交
<input type="text" name="text" > <input type="submit"> </form> </body> </html>
过滤器页面：
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response; //放行！！！——————————————————————
chain.doFilter(newRequest, res); }
编写的servlet的get方法中：
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String str=request.getParameter("text");
if(str!=null)System.out.println(str);
response.getWriter().write(str);
}
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" alt="" width="287" />
我们在过滤器中注释掉
//req.setCharacterEncoding("utf-8");
// res.setContentType("text/html;charset=utf-8");
|
控制台显示
|
JSP页面显示
|
|
|
GET
|
你好啊
|
???
|
|
POST
|
ä½ å¥½å
|
：浣犲ソ鍟�
|
在filte过滤器加上：request.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=utf-8");
|
控制台显示
|
JSP页面显示
|
|
|
GET
|
你好啊
|
你好啊 |
|
POST
|
你好啊
|
你好啊 |
这里JSP页面出现乱码是因为：在getParameter()方法中，得到的字符串是乱码的。
在Filter中：
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response; //放行！！！——————————————————————
//
EnhanceRequest newRequest=new EnhanceRequest(req);
// req.setCharacterEncoding("utf-8");
// res.setContentType("text/html;charset=utf-8");
System.out.println("filtering");
chain.doFilter(newRequest, res); }
使用装饰者模式，增强getParameter().
小插曲： 装饰者模式：
增强类与被增强类实现统一接口。
增强类中传入被增强的类
需要增强的方法重写。
之后在Filter中增强req：
class EnhanceRequest extends HttpServletRequestWrapper {
private HttpServletRequest request;
public EnhanceRequest(HttpServletRequest req) {
super(req);
this.request=req;
}
//对getParameter增强
@Override
public String getParameter(String name) {
String parameter =request.getParameter(name);//乱码
try {
parameter=new String(parameter.getBytes("iso8859-1"),"UTF-8");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return parameter;
}
}
|
控制台显示
|
JSP页面显示
|
|
|
GET
|
???
|
???
|
|
POST
|
你好啊 |
???
|
同时发现：当JSP页面中去除掉这条代码contentType="text/html; charset=UTF-8"，将造成JSP页面显示数据为乱码。
结论：要解决JSP页面和控制台的乱码问题，只要在filter过滤器加上：request.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=utf-8");
或者就在servlet页面上添加：request.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=utf-8");
便可解决POST和GET方法的乱码问题。