jsp Filter 实现编码过滤，和登录验证

登陆页面login.jsp

   
   


   

用户名:

二：Servlet页面Servlet.java

package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
    doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
    //取得内容
    String name = request.getParameter("name");
    //设置内容到下一页面
    request.getSession().setAttribute("name", name);
    //客户端跳转
    response.sendRedirect("admin/ok.jsp");
    //request.getRequestDispatcher("admin/ok.jsp").forward(request, response);
}

}

三：Filter过滤器实现统一中文编码FilterTest2.java

package com.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterTest2 implements Filter {

public void destroy() {
   // TODO Auto-generated method stub

}

public void doFilter(ServletRequest arg0, ServletResponse arg1,
    FilterChain arg2) throws IOException, ServletException {
   System.out.println("**********统一中文过滤***********");
   try{
    arg0.setCharacterEncoding("utf-8");
    arg1.setCharacterEncoding("utf-8");
   }catch(Exception e){
    e.printStackTrace();
   }
   arg2.doFilter(arg0, arg1);
}

public void init(FilterConfig arg0) throws ServletException {
   // TODO Auto-generated method stub

}

}

四：Firlter过滤器实现登陆验证FirterTest.java

package com.filter;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
* @author
*
*/
public class FilterTest implements javax.servlet.Filter {

public void destroy() {
   // TODO Auto-generated method stub
   System.out.println("**********销毁***********");
}

public void doFilter(ServletRequest arg0, ServletResponse arg1,
    FilterChain arg2) throws IOException, ServletException {
   System.out.println("**********过滤2***********");
    //强制转换取得Request对象
    HttpServletRequest req = (HttpServletRequest) arg0;
    //强制转换取得Response对象
    HttpServletResponse res = (HttpServletResponse)arg1;
    if(req.getSession().getAttribute("name")!=null){
     arg2.doFilter(arg0, arg1);
    }else{
     //客户端跳转
     res.sendRedirect("../login.jsp");
     //res.setHeader("refresh", "1;url=../login.jsp");
     //arg0.getRequestDispatcher("../login.jsp").forward(arg0, arg1);
    }
}

public void init(FilterConfig arg0) throws ServletException {
   // TODO Auto-generated method stub
   System.out.println("**********初始化***********");
}

}

五：Admin文件夹下的ok.jsp页面

再次欢迎${name }的到来~

六：web.xml的设置

    Servlet
    /Servlet


    index.jsp

   
test2
com.filter.FilterTest2


test2
/*




test
com.filter.FilterTest


test
/admin/*

//先过滤全部文件夹，再进行admin文件夹下的过滤~