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();          }      } }