[javaEE] JDBC快速入门

JDBC：Java Data Base Connectivity java数据库连接

1.组成JDBC的两个包：主要是接口

java.sql javax.sql

2.相应JDBC的数据库实现

在tomcat的目录下面添加mysql-connector-java-5.0.8-bin.jar这个数据库驱动包

package com.tsh.web;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
*/
public class DbServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
*/
public DbServlet() {
super();
// TODO Auto-generated constructor stub
}

/**
*/
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {

try {
// 注册数据库驱动
//DriverManager.registerDriver(new Driver());
//使用反射的方式
Class.forName("com.mysql.jdbc.Driver");
//获取数据库连接，导包的时候，注意要导java.sql下的，面向接口编程
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/java","root","root");
//获取传输器对象
Statement statement=conn.createStatement();
//获取结果集对象
ResultSet resultSet=statement.executeQuery("select * from user");
//遍历
while(resultSet.next()){
String username=resultSet.getString("username");
response.getWriter().write(username);
}
} catch (Exception e) {
e.printStackTrace();
}
}

/**
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
}

}