userdaoimpl_jdbc.java

一个ajax源码

package demo;
import java.sql.*;
public class UserDaoImpl_Jdbc implements UserDaoIf{
 public boolean checkUser(String userName){
Connection con=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
	 try{
		 con=getConnection();
		 String sql="select * from ajax_user where username=?";
		 pstmt=con.prepareStatement(sql);
		 pstmt.setString(1,userName);
		 re=pstmt.executeQuery();
		 if(rs.next())
		 {
			 return true;
		 }else{
			 return false;
		 }
	 }catch(Exception e)
	 {
		 e.printStackTrace();
		 return false;
	 }finally{
		 close(con,pstmt,rs);
	 }
 }
 public User findUserByName(String userName){
   Connection con=null;
   PreparedStatement pstmt=null;
   ResultSet rs=null;
   try{
	   con=getConnection();
	   String sql="select * from ajax_user where username=?";
	   pstmt=con.prepareStatment(sql);
	   pstmt.setString(1,userName);
	   rs = pstmt.executeQuery();
	   if(rs.next()){
		   User user=new User();
		   user.setUserId(rs.getInt(1));
		   user.setUserName(rs.getStrng(2));
		   user.setPassWord(rs.getString(3));
		   user.setGender(rs.getString(4));
		   return user;
	   }else{
		   return null;
	   }
   }catch(Exception e)
	 {
	   e.printStackTrace();
	   return null;
	 }
 }
 public Connection getConnection(){
 Class.forName("com.mysql.jdbc.Driver");
    return 
	 DriverManager.getConnection("jdbc:mysql://localhost:3306/camp","root","root");
 }
 public void close(Connection con,PreparedStatement pstmt,ResultSet rs)
	try{
	 if(con != null)con.close();
	 if(pstmt != null)pstmt.close();
	 if(rs !=null) re.close();
 }catch(Exception e){
 e.printStackTrace();
 }
}