JDBC學習筆記（3）之jdbc簡單封裝

Jdbc封裝，程序結束連接自動關閉，不用手工關閉連接；

</pre><p></p><p></p><p><pre name="code" class="java">package JDBC1208;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Jdbcdao {
	private static String url="jdbc:mysql://127.0.0.1:3306/work2";
	private static String user="**";
	private static String password="**";
	private static JdbcTemplate obj =null;
	public static JdbcTemplate getJdbcTemplate() {
		if(obj==null)
		{
			obj=new JdbcTemplate();
			try {
				Class.forName("com.mysql.jdbc.Driver");//要導入jar包!!!
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			Connection conn=null;
			try {
				conn=DriverManager.getConnection(url, user, password);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			obj.setConnection(conn);
		}
		return obj;
	}
}

package JDBC1208;


import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class JdbcTemplate {
	private static ResultSet rs=null;
	private static Connection conn;
	private static Statement st=null;
	public void setConnection(Connection connection)
	{
		conn=connection;
	}
	public ResultSet excuteQuery(String sql)
	{
		if(st!=null)
		{
			try {
				st.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			st=null;
			return null;
		}
		if(conn==null)
		{
			return null;
		}
			try {
				st=conn.createStatement();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			try {
				rs=st.executeQuery(sql);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
		}
			return rs;
	}
	/*public static Connection getConn() {
		return conn;
	}
	public static void setConn(Connection conn) {
		JdbcTemplate.conn = conn;
	}*/
	


}

executeQuery返回ResultSet；

executeUpdate返回int；即數據被改變的rows；