[javaEE] JDBC快速入門，javaeejdbc快速入門

[javaEE] JDBC快速入門，javaeejdbc快速入門

JDBC：Java Data Base Connectivity java數據庫連接

1.組成JDBC的兩個包：主要是接口

java.sql javax.sql

2.相應JDBC的數據庫實現

在tomcat的目錄下面添加mysql-connector-java-5.0.8-bin.jar這個數據庫驅動包

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 {
            // 注冊數據庫驅動
            //DriverManager.registerDriver(new Driver());
            //使用反射的方式
            Class.forName("com.mysql.jdbc.Driver");
            //獲取數據庫連接，導包的時候，注意要導java.sql下的，面向接口編程
            Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/java","root","root");
            //獲取傳輸器對象
            Statement statement=conn.createStatement();
            //獲取結果集對象
            ResultSet resultSet=statement.executeQuery("select * from user");
            //遍歷
            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 {
    }

}