DAO模式数据库操作源代码

      package cn.mldn.lxh.Dao.Impl;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import cn.mldn.lxh.Dao.userDAO;
import cn.mldn.lxh.Dao.dbcon.User;
import cn.mldn.lxh.Dao.dbcon.dbConnection;


public class userDAOImpl implements userDAO{
	public void insert(User user) throws Exception {
		System.out.println("-----insert----");
		dbConnection conn=new dbConnection();
		PreparedStatement pstmt=null;
		String sql="insert into user_information(name,password,age,email) values(?,?,?,?)";
		System.out.println(sql);
		System.out.println(user.getUserName());
		try{
			System.out.println("start insert");
			pstmt=conn.getConnection().prepareStatement(sql);
			System.out.println(sql);
			pstmt.setString(1, user.getUserName());
			
			System.out.println("insert beginning");
			pstmt.setString(2, user.getPassword());
			pstmt.setInt(3, user.getAge());
			pstmt.setString(4, user.getEmail());
			pstmt.executeUpdate();
			System.out.println("insert implement....");
			pstmt.close();
			
		}
		
		catch(Exception e)
		{
			System.out.println("insert fail");
			e.printStackTrace();
			throw new Exception("操作中出现错误");
			
		}

		finally{
			conn.close();
		}
	}
	public void update(User user) throws Exception {
		dbConnection conn=null;
		PreparedStatement pstmt=null;
		String sql="update user_information set name=?,password=?,age=?,email=? where id=?";
		try{
			pstmt=conn.getConnection().prepareStatement(sql);
			pstmt.setString(1, user.getUserName());
			pstmt.setString(2, user.getPassword());
			pstmt.setInt(3, user.getAge());
			pstmt.setString(4, user.getEmail());
			pstmt.setInt(5, user.getId());
			pstmt.executeUpdate();
			pstmt.close();
		}
		
		catch(Exception e)
		{
			throw new Exception("操作中出现错误");
			
		}
		finally{
			conn.close();
		}
	}
	public void delete(int id)    throws Exception {	
		dbConnection conn=null;
	PreparedStatement pstmt=null;
	String sql="delete from user_information where id=?";
	try{
		pstmt=conn.getConnection().prepareStatement(sql);
		pstmt.setInt(1, id);
		pstmt.executeUpdate();
		pstmt.close();
	}
	
	catch(Exception e)
	{
		throw new Exception("操作中出现错误");
		
	}
	finally{
		conn.close();
	}
	}
	public User queryById(int id) throws Exception {
		dbConnection conn=null;
		User user=null;
		PreparedStatement pstmt=null;
		String sql="select * from user_information where id=?";
		try{
			pstmt=conn.getConnection().prepareStatement(sql);
			pstmt.setInt(1, id);
			ResultSet rs=pstmt.executeQuery();
			if(rs.next())
			{
				user=new User();
				user.setUserName(rs.getString("name"));
				user.setPassword(rs.getString("password"));
				user.setAge(rs.getInt("age"));
				user.setEmail(rs.getString("email"));
			}
			pstmt.close();
		}
		
		catch(Exception e)
		{
			throw new Exception("操作中出现错误");
			
		}
		finally{
			conn.close();
		}
		return user;
	}
	public List queryAll()        throws Exception {
		List all=null;
		dbConnection conn=null;
		String sql="select * from user_information";
		PreparedStatement pstmt=null;
		try{
			conn=new dbConnection();
			pstmt=conn.getConnection().prepareStatement(sql);
			ResultSet rs=pstmt.executeQuery();
			while(rs.next())
			{
				User user=new User();
				user.setId(rs.getInt("id"));
				user.setUserName(rs.getString("name"));
				user.setPassword(rs.getString("password"));
				user.setAge(rs.getInt("age"));
				user.setEmail(rs.getString("email"));
				all.add(user);
			}
		}catch(Exception e){}
		finally{conn.close();}
		return all;
	}
	public List queryByLike(String cond) throws Exception {
		List all=new ArrayList();
		dbConnection conn=null;
		PreparedStatement pstmt=null;
		String sql="select * from user_information where name like ? or remark like ?";
		try{
			conn=new dbConnection();
			pstmt=conn.getConnection().prepareStatement(sql);
			pstmt.setString(1, cond);
			pstmt.setString(2, cond);
			ResultSet rs=pstmt.executeQuery();
			while(rs.next())
			{
				User user=new User();
				user.setId(rs.getInt("id"));
				user.setUserName(rs.getString("username"));
				user.setPassword(rs.getString("password"));
				user.setAge(rs.getInt("age"));
				user.setEmail(rs.getString("email"));
				all.add(user);
			}
		}catch(Exception e){}
		finally{conn.close();}
		return all;
	}
}