java -> MYSQL 连接 通过 JDBC

先从 http://dev.mysql.com/downloads/connector/j/ 下载 然后把根目录的  mysql-connector-java-5.1.39-bin.jar 导入JAVA 工程

DB.java 用于连接 数据库

package main;


import java.sql.Connection;  
import java.sql.DriverManager;  
import java.sql.PreparedStatement;  
import java.sql.SQLException;  
  
public class DB {  
	//其中HOST / 后面 是 数据库名称
    public static final String url = "jdbc:mysql://127.0.0.1/wl";  
    public static final String name = "com.mysql.jdbc.Driver";  
    public static final String user = "root";  
    public static final String password = "";  
  
    public Connection conn = null;  
    public PreparedStatement pst = null;  
  
    public DB(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();  
        }  
    }  
}  

DbDo.java 用于 操作 数据库

package main;

import java.sql.ResultSet;
import java.sql.SQLException;

public class DbDo {

    static String sql = null;  
    static DB db1 = null;  
    static ResultSet ret = null;  
  
    public static void main(String[] args) {  
        sql = "select * from stuinfo";//SQL语句  
        db1 = new DB(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  
            ret.close();  
            db1.close();//关闭连接  
        } catch (SQLException e) {  
            e.printStackTrace();  
        } 
	}

}