DAO测试案例（一）

package com.gyarmy.dao;

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 com.gyarmy.Utils.JdbcUtils;
import com.gyarmy.domain.Users;

public class UserDao {
	
	public void insert(Users user){
		Connection conn = null;
		Statement stmt =null;
		
		try {
			conn = JdbcUtils.getConnection();
			stmt = conn.createStatement();
			//插入操作
			String sql = "insert into users values(null,'"+user.getUsername()+"','"+user.getPassword()+"','"+user.getNickname()+"')";
			System.out.println(sql);
			stmt.executeUpdate(sql);	
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JdbcUtils.releaseRes(null, stmt, conn);
		}
	}
	
	public void update(Users user){
		
		Connection conn = null;
		Statement stmt =null;
		
		try {
			conn = JdbcUtils.getConnection();
			stmt = conn.createStatement();
			//插入操作
			String sql = "update users set username='"+user.getUsername()+"' ,password = '"+user.getPassword()+"' where nickname='"+user.getNickname()+"'";
			System.out.println(sql);
			stmt.executeUpdate(sql);	
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JdbcUtils.releaseRes(null, stmt, conn);
		}
	}
	
	public void delete(Users user){
		Connection conn = null;
		Statement stmt =null;
		
		try {
			conn = JdbcUtils.getConnection();
			stmt = conn.createStatement();
			//插入操作
			String sql = "delete from users where nickname = '"+user.getNickname()+"'";
			System.out.println(sql);
			stmt.executeUpdate(sql);	
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JdbcUtils.releaseRes(null, stmt, conn);
		}
	}
	
	
	public List selectAll(){
		List list = new ArrayList();
		
		Connection conn = null;
		Statement stmt =null;
		ResultSet rs = null;
		
		
		try {
			conn = JdbcUtils.getConnection();
			stmt = conn.createStatement();
			//插入操作
			String sql = "select * from users";
			rs = stmt.executeQuery(sql);
			Users user = null;
			while(rs.next())
			{
				user = new Users();
				String username = rs.getString("username");
				user.setUsername(username);
				
				String password = rs.getString("password");
				user.setUsername(username);
				
				String nickname = rs.getString("nickname");
				user.setUsername(username);
				
				list.add(user);
			}
			return list;
			
			
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}finally{
			JdbcUtils.releaseRes(rs, stmt, conn);
		}
	
	}
}