//驅動程式名
		String driverName = "com.mysql.jdbc.Driver";
		//資料庫使用者名稱 
		String userName = "root";
		//密碼 
		String userPasswd = "12345678";
		//資料庫名 
		String dbName = "testweb";
		//表名 
		String tableName = "person";
		//聯結字串 
		String url = "jdbc:mysql://localhost:3306/" + dbName + "?user="
				+ userName + "&password=" + userPasswd;
		//需要try-catch，註冊資料庫
		Class.forName("com.mysql.jdbc.Driver");
		//獲取資料庫連線，也可以Connection connection = DriverManager.getConnection( "jdbc:mysql://localhost:3306/testWeb" ，“root”，“12345678”);
		Connection connection = DriverManager.getConnection(url);
		//獲取statement
		Statement statement = connection.createStatement();
		String sql = "select * from " + tableName;
		//String sql = "insert into person (name,age,sex) values ('孫悟空','55','猴')";
		//String sql = "delete from person where name='孫悟空'";
		//String sql = "update person set name='陽陽' where description='女神'";
		//執行查詢語句
		ResultSet rs = statement.executeQuery(sql);
		//執行新增刪除修改語句
		//statement.executeUpdate(sql);
		...
		//查詢的時候用re.next()遍歷，out列印rs，注意getString（1）是從1開始而不是0
		<%
			while (rs.next()) {
			out.print(rs.getString(1));
			out.print(rs.getString(2));
				%>
		//前面通過ResultSet使用了Query後面的rs就要close（），statement和connection要記得關閉
		rs.close();
		statement.close();
		connection.close();
		
 

注意connection一定要關閉，否則會一直佔用連線池

然後，記得新建專案的時候要匯入相關jar包：Apache的，jdbc的（mysql-connector-java-5.1.47.jar）。