急，在线等！！！关于resultset.next()

下面是源码，麻烦楼上的几位大哥帮忙看看
Register:package com.migo2008.servlet;import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.migo2008.javabean.*;public class Register extends HttpServlet { private Operater op;
private User user;
public void destroy() {
super.destroy();
} public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
} //注册新用户
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("uname");
String password=request.getParameter("upassword");
user=new User();
user.setUname(name);
user.setUpassword(password);
if(!user.isExist()){
op.exeuteInsert(user);
RequestDispatcher req=request.getRequestDispatcher("forward.jsp");
req.forward(request, response);
}else{
RequestDispatcher req=request.getRequestDispatcher("error.jsp");
req.forward(request, response);
}
} public void init() throws ServletException {
op=OperaterFactory.getOperater();
}}
Operaterpackage com.migo2008.javabean;import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;/*
* 完成对IOperater的实现，对表进行操作
*/
public class Operater implements IOperater{
private String sql =null;
private DBConnection con =null;
private PreparedStatement ps =null;
private ResultSet rs =null;

//实现删除
public void executeDelete(User user) {

}
//实现按ID查询
public ResultSet executeSelecte(String id) {
con=new DBConnection();
sql="select [user_id] from [user] where [user_id]=?";
try {
ps=con.getConnect().prepareStatement(sql);
ps.setString(1, id);
rs=ps.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
//实现添加
public void exeuteInsert(User user) {
con= new DBConnection();
sql="insert into [user] values(?,?)";
try {
ps=con.getConnect().prepareStatement(sql);
ps.setString(1,user.getUname());
ps.setString(2, user.getUpassword());
ps.executeUpdate();
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

//实现修改
public void executeUpdate(User user) {

}}User:
[code=Java]
package com.migo2008.javabean;import java.sql.ResultSet;
import java.sql.SQLException;
public class User {
private String uname;
private String upassword;
private boolean exist;
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getUpassword() {
return upassword;
}
public void setUpassword(String upassword) {
this.upassword = upassword;
}

//判断用户是否存在

public boolean isExist(){
Operater op=OperaterFactory.getOperater();
try {
ResultSet rs=op.executeSelecte(uname);
System.out.print(rs.next());
if(rs.next())
{
exist=true;
}
else{
exist=false;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return exist;
}
}[/code]

sql="select [user_id] from [user] where [user_id]=?";
你是要根据用户ID去查找这个用户是否存在还是想这样
sql="select [user_id] from [user] where [user_name]=?";
根据用户名uname查ID是否存在?
如果是第一种,参数应该是要查找的用户ID.

user表中只有两个字段：user_id,user_password.
sql="select [user_id] from [user] where [user_id]=?";
作用是要根据用户输入查询表中是否存在这个用户

可能是rs的指针位置问题用下面的代码覆盖下你的方法，看看//判断用户是否存在
public boolean isExist(){
        Operater op=OperaterFactory.getOperater();
        try {
            ResultSet rs=op.executeSelect(uname);
            rs.beforeFirst();
            if(rs.next())
            {
                exist=true;
            }
            else{
                exist=false;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return exist;
    }

的确是什么也没改啊！！！
这用的是myeclipse的内置tomcat，这算不算bug？？？

o ! 那个给我发消息的就是你啊！！呵呵！我从来不建议用eclipse内置的Tomcat,原因很简单，因为正式的运行环境不适那样的。Tomcat还是单独运行比较好
1 用控制台运行，可以很清楚的看到各种输出
2 用服务运行，需要配合第三方的日志工具，在我的CSDN下载资源里面有。类似lunix的 tail 工具

调试易

急，在线等！！！关于resultset.next()

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