usermanager.java

精品课程的java源码

package com.zzx.manager;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.zzx.bean.News;
import com.zzx.bean.Users;
import com.zzx.util.DataConn;

public class UserManager{
  
	 Connection conn = null;
	 PreparedStatement psmt = null;
	
	public List queryUser() {

		String sql = "select * from users where flag=1";
		List all = new ArrayList();
		ResultSet rs = null;
		try {
			conn = new DataConn().getConn();
			psmt = conn.prepareStatement(sql);
			rs = psmt.executeQuery();

			while (rs.next()) {
				Users user = new Users();
				user.setFlag(rs.getInt(1));
				user.setUsername(rs.getString(2));
				user.setPassword(rs.getString(3));
				
				all.add(user);
			}
			rs.close();
			psmt.close();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return all;

	}
	
	// 对用户插入的操作
	public void insert(Users user) {
		String sql = "insert into users(username,password,flag) values(?,?,?);";
		
		try {
			conn = new DataConn().getConn();
			psmt = conn.prepareStatement(sql);
			psmt.setString(1, user.getUsername());
			psmt.setString(2, user.getPassword());
			psmt.setInt(3, user.getFlag());
			psmt.executeUpdate();
			psmt.close();
			System.out.println("user insert successfully!");
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

	}
	public Users queryByUsername(String username) {
		
		String sql = "SELECT id,username,password,flag FROM users WHERE username=? and flag =1";	
		ResultSet rs = null;
		Users user = new Users();
		try {
			conn = new DataConn().getConn();
			psmt = conn.prepareStatement(sql);
			psmt.setString(1, username);
			rs = psmt.executeQuery();
			
			if(rs.next()){
				user.setId(rs.getInt(1));
				user.setUsername(rs.getString(2));
				user.setPassword(rs.getString(3));
				user.setFlag(rs.getInt(4));
				}
			rs.close();
			psmt.close();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return user;
	}
	// 对消息进行更新的操作
    public void updateUser(Users user){
   	     
    	String sql = "UPDATE users SET username=?,password=?,flag=? WHERE id=?" ;		 	 
		 try {
			    conn = new DataConn().getConn();
				psmt = conn.prepareStatement(sql);					
				psmt.setString(1, user.getUsername());
				psmt.setString(2, user.getPassword());
				psmt.setInt(3, user.getFlag());
				psmt.setInt(4, user.getId());		
				psmt.executeUpdate();
				psmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally{
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}			 
    }
	
    
    
    
	public static void main(String[] args){
		
		UserManager um =new UserManager();
//		List users = um.queryUser();
//		Iterator itor = users.iterator();
//		while(itor.hasNext()){
//			Users user=(Users)itor.next();
//			System.out.println(user.getUsername());
//			System.out.println(user.getPassword());
//		}
		
		Users user = new Users();
		user.setId(3);
		user.setFlag(1);
		user.setPassword("test");
		user.setUsername("test");
		um.updateUser(user);
	}
}