usermanager.java

这是尚学堂马士兵老师讲解的网上购物系统

package cn.edu.chu.user;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import cn.edu.chu.util.DB;

public class UserManager {
	public static List<User> getUsers(){ 
		List<User> list=new ArrayList<User>();
		Connection conn=DB.getConn();
		String sql="select * from user";
		ResultSet rs=DB.executeQuery(conn, sql);
		try {
			while(rs.next()){
				User u=new User();
				u.setId(rs.getInt("id"));
				u.setUsername(rs.getString("username"));
				u.setPassword(rs.getString("password"));
				u.setPhone(rs.getString("phone"));
				u.setAddr(rs.getString("addr"));
				u.setRdate(rs.getTimestamp("rdate"));
				list.add(u);
				
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			DB.close(rs);
			DB.close(conn);
		}		
		return list;
		
	}
	
	public static User getUser(int id){ 
		User u=null;
		Connection conn=DB.getConn();
		String sql="select * from user where id="+id;
		ResultSet rs=DB.executeQuery(conn, sql);
		try {
			while(rs.next()){
				u=new User();
				u.setId(rs.getInt("id"));
				u.setUsername(rs.getString("username"));
				u.setPassword(rs.getString("password"));
				u.setPhone(rs.getString("phone"));
				u.setAddr(rs.getString("addr"));
				u.setRdate(rs.getTimestamp("rdate"));						
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			DB.close(rs);
			DB.close(conn);
		}		
		return u;
		
	}
	
	public static boolean foundUser(String username){ 
		Connection conn=DB.getConn();
		String sql="select * from user where username='"+username+"'";
//System.out.println(sql);
		ResultSet rs=DB.executeQuery(conn, sql);
		try {	
			while(rs.next()){
//System.out.println("进来了,呵呵!");
				return true;	
			}						
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			DB.close(rs);
			DB.close(conn);
		}		
		return false;		
	}
	
	public static void deleteUser(int id){
		Connection conn=null;
		Statement stmt=null;
		String sql="delete from user where id="+id;
		try {
			conn=DB.getConn();
			stmt=DB.getStmt(conn);
			stmt.executeUpdate(sql);
			
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			DB.close(stmt);
			DB.close(conn);
		}		
		
	}
}