java 项目连接mysql 数据库

 1.创建java项目

2. 引入mysql-connection-.jar文件(https://dev.mysql.com/downloads/connector/j/)

3.写DBHelper.java

package com.ccl.dbConnection;

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://192.168.1.231/student";  
    public static final String name = "com.mysql.jdbc.Driver";  
    public static final String user = "aa";  
    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();  
        }  
    }  
}

4.测试类

package com.ccl.test;

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

import com.ccl.dbConnection.DBHelper;

public class ConnectionTest {

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

}