JAVA：JDBC连接MySQL数据库-蒲公英云

JAVA：JDBC连接MySQL数据库

一、下载mysql连接包,放到项目中

a) 首先要到mysql官网下载Connector/J地址是：

http://www.mysql.com/downloads/connector/j/

Center

Center 1

b) 解压后的文件夹是：

Center 2

c) 拷贝到工程中：

Center 3

d) 鼠标右键：Add to Build Path

Center 4

二、新建一个DBHelper类用来打开或关闭数据库：

package com.db;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class DBHelper {
    public static final String url = "jdbc:mysql://127.0.0.1/xxxxx";
    public static final String name = "com.mysql.jdbc.Driver";
    public static final String user = "root";
    public static final String password = "123456";
    public Connection conn = null;
    public PreparedStatement pst = null;
    public DBHelper(String sql) {
        try {
            Class.forName(name);// 指定连接类型
            conn = DriverManager.getConnection(url, user, password);// 获取连接
            pst = conn.prepareStatement(sql);// 准备执行语句
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public void close() {
        try {
            this.conn.close();
            this.pst.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

三、新建一个HelloJDBC类用来执行查询操作：

package com.db;
import java.sql.ResultSet;
import java.sql.SQLException;
public class HelloJDBC {
    static String sql = null;  
    static DBHelper db1 = null;  
    static ResultSet ret = null;  
    public void query() {
         sql = " select * from zduser ";//SQL语句  
         db1 = new DBHelper(sql);//创建DBHelper对象  
         try {  
             ret = db1.pst.executeQuery();//执行语句，得到结果集  
             while (ret.next()) {  
                 String uid = ret.getString(1);  
                 String ufname = ret.getString(2);  
                 String ulname = ret.getString(3);  
                 String udate = ret.getString(4);  
                 System.out.println(uid + "\t" + ufname + "\t" + ulname + "\t" + udate );  
             }//显示数据  
         } catch (SQLException e) {  
             e.printStackTrace();  
         } finally {
             try {
                ret.close();
                db1.close();//关闭连接  
            } catch (SQLException e) {
                e.printStackTrace();
            }  
         }
    }
}