这句应放哪啊

Question

 if(passed1==true&&passed2==true){response.sendRedirect("login.jsp");}
应该放到程序哪才不报错？package com.yourcompany.struts.action;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.ArrayList;
import dao.LoginDao; public class Validaction extends HttpServlet {
   public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
   response.setCharacterEncoding("UTF-8");
     PrintWriter out = response.getWriter();
     String qxfp =request.getParameter("qxfp");
        String username =request.getParameter("username");
        System.out.println(qxfp+username);
        if(qxfp!=null&&username==null){
        boolean passed1 = validateDate1(qxfp,request.getRemoteAddr());
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
       String message1 = "此岗位未授权予本机!";
        if (passed1) {
            message1 = "√";
       }
        System.out.println(message1+passed1);
        out.println("<response>");
        out.println("<passed1>" + Boolean.toString(passed1) + "</passed1>");
        out.println("<message1>" + message1 + "</message1>");
        out.println("</response>");
        out.close();
         }
        
       if(qxfp!=null&&username!=null){
       boolean passed2 = validateDate2(qxfp,username);
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
       String message2 = "该岗位无此用户名!";
           if (passed2) {
            message2 = "√";
        }
           System.out.println(message2+passed2);
        out.println("<response>");
        out.println("<passed2>" + Boolean.toString(passed2) + "</passed2>");
        out.println("<message2>" + message2 + "</message2>");
        out.println("</response>");
        out.close();}
   }
  
   private boolean validateDate1(String date,String date0) {
       boolean isValid = true;
           LoginDao loginDao=new LoginDao();
        ArrayList ips=loginDao.getIpByQxfp(date);
        int size = ips.size();
         if(size>0){
        for(int i=0;i<size;i++){
         String dateIp = (String)ips.get(i);
          System.out.println(dateIp);
         if(dateIp.equals(date0)) {                 
        isValid = true;
         break;          }
         else isValid = false;
         continue; 
         }}
        else isValid = false;       
         return isValid;
   }
   private boolean validateDate2(String date,String date0) {
       boolean isValid = true;
                LoginDao loginDao=new LoginDao();
             ArrayList usernames=loginDao.getUsernameByQxfp(date);
               int size = usernames.size();
               if(size>0){
               for(int i=0;i<size;i++){
             String user = (String)usernames.get(i);
              System.out.println(user);
             if(user.equals(date0)) {                 
            isValid = true;
             break;          }
             else isValid = false;
             continue; 
             }}
            else isValid = false;
               return isValid;
         } }

Answer 1

if(passed1==true&&passed2==true){response.sendRedirect("login.jsp");} 
不需要这么写吧
if(passed1&&passed2){response.sendRedirect("login.jsp");} 
就可以了

Answer 2

if(passed1&&passed2){response.sendRedirect("login.jsp");} 放到哪里才对？package com.yourcompany.struts.action; 
import java.io.*; 
import javax.servlet.*; 
import javax.servlet.http.*; 
import java.util.ArrayList; 
import dao.LoginDao; public class Validaction extends HttpServlet { 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
    throws ServletException, IOException { 
  response.setCharacterEncoding("UTF-8"); 
    PrintWriter out = response.getWriter(); 
    String qxfp =request.getParameter("qxfp"); 
        String username =request.getParameter("username"); 
        System.out.println(qxfp+username); 
        if(qxfp!=null&&username==null){ 
        boolean passed1 = validateDate1(qxfp,request.getRemoteAddr()); 
        response.setContentType("text/xml"); 
        response.setHeader("Cache-Control", "no-cache"); 
      String message1 = "此岗位未授权予本机!"; 
        if (passed1) { 
            message1 = "√"; 
      } 
        System.out.println(message1+passed1); 
        out.println(" <response>"); 
        out.println(" <passed1>" + Boolean.toString(passed1) + " </passed1>"); 
        out.println(" <message1>" + message1 + " </message1>"); 
        out.println(" </response>"); 
        out.close(); 
        } 
        
      if(qxfp!=null&&username!=null){ 
      boolean passed2 = validateDate2(qxfp,username); 
      response.setContentType("text/xml"); 
        response.setHeader("Cache-Control", "no-cache"); 
      String message2 = "该岗位无此用户名!"; 
          if (passed2) { 
            message2 = "√"; 
        } 
          System.out.println(message2+passed2); 
        out.println(" <response>"); 
        out.println(" <passed2>" + Boolean.toString(passed2) + " </passed2>"); 
        out.println(" <message2>" + message2 + " </message2>"); 
        out.println(" </response>"); 
        out.close();} 
  } 
  
  private boolean validateDate1(String date,String date0) { 
      boolean isValid = true; 
          LoginDao loginDao=new LoginDao(); 
      ArrayList ips=loginDao.getIpByQxfp(date); 
      int size = ips.size(); 
      if(size>0){ 
      for(int i=0;i <size;i++){ 
      String dateIp = (String)ips.get(i); 
      System.out.println(dateIp); 
      if(dateIp.equals(date0)) {                
    isValid = true; 
      break;          } 
      else isValid = false; 
      continue; 
      }} 
      else isValid = false;      
      return isValid; 
  } 
  private boolean validateDate2(String date,String date0) { 
      boolean isValid = true; 
              LoginDao loginDao=new LoginDao(); 
          ArrayList usernames=loginDao.getUsernameByQxfp(date); 
            int size = usernames.size(); 
            if(size>0){ 
            for(int i=0;i <size;i++){ 
          String user = (String)usernames.get(i); 
          System.out.println(user); 
          if(user.equals(date0)) {                
        isValid = true; 
          break;          } 
          else isValid = false; 
          continue; 
          }} 
          else isValid = false; 
            return isValid; 
        } }

Answer 3

放在哪都不对。因为你passed1在第一个if块里定义，passed2在第二个if块里定义。

Answer 4

楼主的思路完全没弄清楚。
首先：
---------------------
这个验证程序用于AJAX 登录验证，此Servlet 输出内容为验证后的 xml 内容，浏览器端javascript 在异步获取xml数据以后根据返回的结果执行相应的功能
所以应该是一个AJAX 登录的实例
此Servlet 只是提供验证的结果，并不存在任何功能性的返回结果
---------------------
正确的操作
javascript:function AJAXResponse(xmlDom){
   try{
   var passed1=xmlDom.selectSingleNode("//passed1").nodeValue.replace(/^\d+|\d+$/g,"");
   var passed2=xmlDom.selectSingleNode("//passed2").nodeValue.replace(/^\d+|\d+$/g,"");;
   if((passed1=="true" || passed1==true) && (passed2=="true" || passed2==true) )){
        window.location="login.jsp";
   }
   catch(e){
       alert(e);
   }
}

Answer 5

 public class Validaction extends HttpServlet {
   public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
   response.setCharacterEncoding("UTF-8");
     PrintWriter out = response.getWriter();
     String qxfp =request.getParameter("qxfp");
        String username =request.getParameter("username");
        System.out.println(qxfp+username);
        boolean passed1 = validateDate1(qxfp,request.getRemoteAddr());
        boolean passed2 = validateDate2(qxfp,username);
        if(qxfp!=null&&username==null){
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
       String message1 = "此岗位未授权予本机!";
        if (passed1) {
            message1 = "√";
       }
        System.out.println(message1+passed1);
        out.println("<response>");
        out.println("<passed1>" + Boolean.toString(passed1) + "</passed1>");
        out.println("<message1>" + message1 + "</message1>");
        out.println("</response>");
        out.close();
         }
        
       if(qxfp!=null&&username!=null){
       
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
       String message2 = "该岗位无此用户名!";
           if (passed2) {
            message2 = "√";
        }
           System.out.println(message2+passed2);
        out.println("<response>");
        out.println("<passed2>" + Boolean.toString(passed2) + "</passed2>");
        out.println("<message2>" + message2 + "</message2>");
        out.println("</response>");
        out.close();}
       if(passed1&&passed2){response.sendRedirect("index.jsp");//这一行
       return;}
      
  }
     
   
   private boolean validateDate1(String date,String date0) {
       boolean isValid = true;
           LoginDao loginDao=new LoginDao();
        ArrayList ips=loginDao.getIpByQxfp(date);
        int size = ips.size();
         if(size>0){
        for(int i=0;i<size;i++){
         String dateIp = (String)ips.get(i);
          System.out.println(dateIp);
         if(dateIp.equals(date0)) {                 
        isValid = true;
         break;          }
         else isValid = false;
         continue; 
         }}
        else isValid = false;       
         return isValid;
   }
   private boolean validateDate2(String date,String date0) {
       boolean isValid = true;
                LoginDao loginDao=new LoginDao();
             ArrayList usernames=loginDao.getUsernameByQxfp(date);
               int size = usernames.size();
               if(size>0){
               for(int i=0;i<size;i++){
             String user = (String)usernames.get(i);
              System.out.println(user);
             if(user.equals(date0)) {                 
            isValid = true;
             break;          }
             else isValid = false;
             continue; 
             }}
            else isValid = false;
               return isValid;
         }
   
 }
 Servlet.service() for servlet Validaction threw exception
java.lang.IllegalStateException
at org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFacade.java:432)
at com.yourcompany.struts.action.Validaction.doGet(Validaction.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)

Answer 6

你已经调用了out=response.getWriter()输出信息到页面上，当out关闭的时候，这个response就应该结束了。不能再用response.sendRedirect方法跳到另一个页面。