JDBC学习笔记（3）之jdbc简单封装

来源：互联网发布：龙岗网络推广szaow 编辑：程序博客网时间：2024/06/04 08:28

Jdbc封装，程序结束连接自动关闭，不用手工关闭连接；

</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");//要导入jar包!!!} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}Connection conn=null;try {conn=DriverManager.getConnection(url, user, password);} catch (SQLException e) {// TODO Auto-generated catch blocke.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 blocke.printStackTrace();}st=null;return null;}if(conn==null){return null;}try {st=conn.createStatement();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {rs=st.executeQuery(sql);} catch (SQLException e) {// TODO Auto-generated catch blocke.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；即数据被改变的rows；

0 0