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();
}
}

}