帮看下这个action的execute方法中的else

Question

public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)throws Exception 
{
          //解析用户请求参数
          String username=request.getParameter("username");
          String pass=request.getParameter("pass");
          //出错提示
          String errMsg=" ";
          //进行服务器端的数据校验
          if(username!=null||username.equals(""))
          {
              errMsg+="你的用户名丢失或没有输入,请重新输入";
            
          }
         
          else if(pass==null||pass.equals(" "));
          {
           errMsg+="你的密码丢失或没有输入，请重新输入";
           
          }
          else
          {   try
           {
          DbDao dd=DbDao.instance("com.microsoft.jdbc.sqlserver.SQLServerDriver","jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=Bus_DataBase","sqq4290","sqq8221620");
          ResultSet rs=dd.query("select password from user_table where username='"+username+"'");
          if(rs.next())
          {
          if(rs.getString("password").equals(pass))
          {
          HttpSession session=request.getSession(true);
          session.setAttribute("name",username);
          return mapping.findForward("welcome");
          }
          else
          {
          errMsg+="你的用户名不存在，请先注册";
          
          }
          }
          
           }
           catch(Exception e)
           {
           request.setAttribute("exception", "业务异常");
           return mapping.findForward("error");
    
           }
          }  
  
          if(errMsg!=null&&!errMsg.equals(""))
          {
           request.setAttribute("err",errMsg);
           return mapping.findForward("input");
          }
          else
          {
           return mapping.findForward("welcome");
          }

        }
上面这个方法里面的else有什么问题？
我的eclispse3.2老对这个地方报错

Answer 1

else
                             {
                                 errMsg+="你的用户名不存在，请先注册";
                                 
                             }
这里面没有return Mapping 

Answer 2

就是里面有try...catch的else,总提示标记：“else”上有语法错误，删除此标记

Answer 3

额。貌似你有过着样的问题了吧。。public ActionForward execute。。方法声明的必须有返回直，为什么你总不返回？？
没仔细看，你加个return null;看看

Answer 4

程序有错
1.String username=request.getParameter("username");应该用trim修饰，pass一样
2.if(username!=null||username.equals(""))；username==null
3.else if(pass==null||pass.equals(" "));equals（“ ”）出空格了
4.mapping没跳转就不看了，在方法里面定义一个公共的jumpTo变量就Ok了，最后做mapping.forward()就可以了

Answer 5

public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)throws Exception 
            {
                  //解析用户请求参数
                  String username=request.getParameter("username");
                  String pass=request.getParameter("pass");
                  //出错提示
                  String errMsg=" ";
                  //进行服务器端的数据校验
                  if(username!=null||username.equals(""))
                  {
                      errMsg+="你的用户名丢失或没有输入,请重新输入";
                        
                  }
                 
                  else if(pass==null||pass.equals(" "));这里多个分号
                  {
                      errMsg+="你的密码丢失或没有输入，请重新输入";
                      
                  }
                  else
                  {      try
                      {
                         DbDao dd=DbDao.instance("com.microsoft.jdbc.sqlserver.SQLServerDriver","jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=Bus_DataBase","sqq4290","sqq8221620");
                         ResultSet rs=dd.query("select password from user_table where username='"+username+"'");
                         if(rs.next())
                         {
                             if(rs.getString("password").equals(pass))
                             {
                                 HttpSession session=request.getSession(true);
                                 session.setAttribute("name",username);
                                 return mapping.findForward("welcome");
                             }
                             else
                             {
                                 errMsg+="你的用户名不存在，请先注册";
                                 
                             }
                         }
                         
                      }
                      catch(Exception e)
                      {
                          request.setAttribute("exception", "业务异常");
                          return mapping.findForward("error");
            
                      }
                  }  
          
                  if(errMsg!=null&&!errMsg.equals(""))
                  {
                      request.setAttribute("err",errMsg);
                      return mapping.findForward("input");
                  }
                  else
                  {
                      return mapping.findForward("welcome");
                  }
        
            }

Answer 6

谢谢各位热心的回答，自己太粗心了
ee4456老兄这次不用在里面添return null 了，因为里面有else