JavaWeb课程复习资料（二）——idea创建JDBC(FactoryDB)

package com.item.jdbc;
public class FactoryDB {
    private static final String URL = "jdbc:mysql://localhost:3306/test?characterEncoding=utf-8";
    private static final String USE = "root";
    private static final String PASSWORD = "root";
}

package com.item.jdbc;
import java.sql.*;
public class FactoryDB {
    private static final String URL = "jdbc:mysql://localhost:3306/test?characterEncoding=utf-8";
    private static final String USE = "root";
    private static final String PASSWORD = "root";
    /**
     * 初始化链接
     *
     * @return
     */
    public static Connection GetConnection() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(URL, USE, PASSWORD);
            Class.forName("com.mysql.jdbc.Driver");
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return conn;
    }
    /**
     * 关闭数据
     * @param conn
     * @param pre
     * @param res
     */
    public static void Close(Connection conn, PreparedStatement pre, ResultSet res) {
        try {
            if (conn != null) {
                conn.close();
            }
            if(pre!=null){
                pre.close();
            }
            if(res!=null){
                res.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

CREATE TABLE `userinfo` (
  `id` int(8) NOT NULL AUTO_INCREMENT,
  `createDate` datetime NOT NULL,
  `userName` varchar(32) NOT NULL,
  `introduce` varchar(200) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO userinfo VALUES (0,NOW(),'admin','管理员很厉害');
INSERT INTO userinfo VALUES (0,NOW(),'zhangsan','张三不认李四');
INSERT INTO userinfo VALUES (0,NOW(),'lisi','李四都认识');
INSERT INTO userinfo VALUES (0,NOW(),'wangwu','大刀王五');
INSERT INTO userinfo VALUES (0,NOW(),'zhaoliu','赵家老六');
INSERT INTO userinfo VALUES (0,NOW(),'ruanxiaoqi','打鱼的阮小七');
INSERT INTO userinfo VALUES (0,NOW(),'baxianwang','贤王一名');
select * from userinfo;

package com.item.demo;
import com.item.jdbc.FactoryDB;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class Action {
    public static void main(String[] args) {
        Connection conn = FactoryDB.GetConnection();
        try {
            PreparedStatement pre = conn.prepareStatement("select * from userinfo");
            ResultSet res = pre.executeQuery();
            while (res.next()){
                System.out.print("id："+res.getInt(1)+"\t");
                System.out.print("createDate："+res.getTime(2)+"\t");
                System.out.print("userName："+res.getString(3)+"\t");
                System.out.println("introduce："+res.getString(4));
            }
            FactoryDB.Close(conn,pre,res);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}