servlet+mysql

package com.hw;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class LinkDB {private static final String DRIVERNAME="com.mysql.jdbc.Driver";private static final String URL="jdbc:mysql://localhost:3306/newdb?useUnicode=true&characterEncoding=utf-8";private static final String USERNAME="root";private static final String PASSWORD="123123";public static Connection getConnection(){Connection conn=null;try {Class.forName(DRIVERNAME);conn=DriverManager.getConnection(URL,USERNAME,PASSWORD);System.out.print(conn.toString());} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}return conn;}//Connectionpublic void insert(){Connection conn=getConnection();String sql="INSERT INTO t_group (id,name) VALUES (13,'123456')";try {PreparedStatement psmt = conn.prepareStatement(sql);int i = psmt.executeUpdate();System.out.print(i);} catch (SQLException e) {e.printStackTrace();}finally{try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}//insertpublic void query(){Connection conn=getConnection();String sql="SELECT id,name FROM t_group";try {PreparedStatement psmt = conn.prepareStatement(sql);ResultSet rs= psmt.executeQuery();while(rs.next()){System.out.println(rs.getString(1));System.out.println(rs.getString("name"));}} catch (SQLException e) {e.printStackTrace();} finally{try {conn.close();conn=null;} catch (SQLException e) {e.printStackTrace();}}}//querypublic static void main(String[] args) {LinkDB linkDB =new LinkDB();linkDB.insert();//linkDB.getConnection();//.query();}//main}//linkDB