Class.forName(driver);

Connection con = DriverManager.getConnection(url,username,password);

import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class DBConnection{public static void main(String[] args){String driver = "com.mysql.jdbc.Driver";//localhost指本機，也可以用本地ip地址代替，3306為MySQL數據庫的默認端口號，“user”為要連接的數據庫名String url = "jdbc:mysql://localhost:3306/user";//填入數據庫的用戶名跟密碼String username = "test";String password = "test";String sql = "select * from user";//編寫要執行的sql語句，此處為從user表中查詢所有用戶的信息try{Class.forName(driver);//加載驅動程序，此處運用隱式注冊驅動程序的方法}catch(ClassNotFoundException e){e.printStackTrace();}try{Connection con = DriverManager.getConnection(url,username,password);//創建連接對象Statement st = con.createStatement();//創建sql執行對象ResultSet rs = st.executeQuery(sql);//執行sql語句并返回結果集while(rs.next())//對結果集進行遍歷輸出{System.out.println("username: "+rs.getString(1));//通過列的標號來獲得數據System.out.println("useradd: "+rs.getString("useradd"));//通過列名來獲得數據System.out.println("userage: "+rs.getInt("userage"));}//關閉相關的對象if(rs != null){try{rs.close();}catch(SQLException e){e.printStackTrace();}}if(st != null){try{st.close();}catch(SQLException e){e.printStackTrace();}}if(con !=null){try{con.close();}catch(SQLException e){e.printStackTrace();}}}catch(SQLException e){e.printStackTrace();}}}