第零种方式: package com.yshx.ss; import java.sql.*; public class conn { public static void main(String[] args) throws SQLException { connection(); } static void connection() throws SQLException { String url="jdbc:mysql://localhost:3306/student"; String user="root"; String pwd="5822323"; String sql="select * from users"; //注册驱动 DriverManager.registerDriver(new com.mysql.jdbc.Driver()); //建立连接 Connection connection=DriverManager.getConnection(url, user, pwd); //创建语句 Statement stmt=connection.createStatement(); //执行语句 ResultSet rs=stmt.executeQuery(sql); //处理结果 while(rs.next()){ System.out.println(rs.getString(2)); } //释放资源 rs.close(); stmt.close(); connection.close(); } } 第一种方式: import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; public class connect { public static void main(String[] args) throws Exception{ Connection conn = null; Statement stmt = null; ResultSet rs=null; // Student rs=null ; //ArrayList<Student> list1=new ArrayList<Student>(); String url="jdbc:mysql://127.0.0.1/student?useUnicode=true&characterEncoding=GB2312"; String user = "root"; String passwd = "5822323"; try { Class.forName("org.gjt.mm.mysql.Driver"); conn = DriverManager.getConnection(url, user,passwd); stmt =conn.createStatement(); //list1=conn.r System.out.println("22222555555555555522222222"); String sql="select * from users"; rs= (ResultSet) stmt.executeQuery(sql); System.out.println("3231231232131313"); while(rs.next()) { System.out.println("name is:"+rs.getInt(1)); } System.out.println("22222222231231232131313"); stmt.close(); conn.close(); }catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } 第二种方式: import java.sql.*; public class Test { public static void main(String[] args) throws Exception{ //Class.forName("com.imaginary.sql.msql.MsqlDriver"); Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/student","root","5822323"); Statement stmt=conn.createStatement(); ResultSet rs=stmt.executeQuery("select * from users"); while(rs.next()){ System.out.println(rs.getString(1)+" 's name is:"+rs.getString(2)); } rs.close(); stmt.close(); conn.close(); } } 第三种方式:(最规范) import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class Connection_perfect { public static void main(String[] agrs){ ResultSet rs=null; Statement stmt=null; Connection conn=null; try{ conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/student","root","5822323"); stmt=conn.createStatement(); rs=stmt.executeQuery("select * from users"); while(rs.next()){ System.out.println(rs.getString(2)); } }catch (SQLException e) { e.printStackTrace(); }finally{ try{ if(rs!=null) rs.close(); if(stmt!=null) stmt.close(); if(conn!=null) conn.close(); }catch (SQLException e) { e.printStackTrace(); } } } } 第四种:jsp页面连接数据库 <%@ page language="java" import="java.util.*" pageEncoding="utf-8" import="java.sql.*"%> <% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css"> --> </head> <body> hello:<br/> <% Class.forName("org.gjt.mm.mysql.Driver").newInstance(); String url = "jdbc:mysql://localhost/student"; String user = "root"; String pwd = "5822323"; Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/student","root","5822323"); String sql="select * from users"; Statement stmt=conn.createStatement(); ResultSet rs=stmt.executeQuery(sql); while(rs.next()) { out.println("name is:"+rs.getString(2)); } %> </body> </html>