userdao.java

笔者试图用最简单易懂的应用为初学者演示spring DAO

package com.ligx.DAO;

import java.util.*;
import java.sql.*;

import com.ligx.Model.UserModel;

public class UserDao {
	
	UserModel model = new UserModel();
	List list = new ArrayList();
	
	public Connection con;
	public Statement stmt;
	public ResultSet rs;
	
	public void openConn() throws Exception
	{
		Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
		String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=Logon";
		con = DriverManager.getConnection(url,"sa","");
		stmt = con.createStatement();
	}
	public void closeConn()
	{
		try{
			
			if(rs!=null)
			{
				rs.close();
			}
			if(stmt!=null)
			{
				stmt.close();
			}
			if(con != null)
			{
				con.close();
			}
		}
		catch(Exception e)
		{
			System.out.println("DBCloseError reason = "+e.toString());
		}
	}
	public List query(String sql)
	{
		list.clear();
		try{
			rs = stmt.executeQuery(sql);
			if(rs !=null)
			{
				while(rs.next())
				{
					Integer id = new Integer(rs.getInt("id"));
					String name = rs.getString("name");
					Integer sex = new Integer(rs.getInt("sex"));
					list.add(new UserModel(id,name,sex));
				}
			}
			
		}
		catch(Exception e){
			System.out.println("sqlError reason = "+e.toString());
		}
		return list;
	}
}