dst product trace prepare except out system dstat exe

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Date;

import org.junit.Test;

public class test {@Test
br/>@Test
PreparedStatement prepareStatement = null;
Connection connection = null;
try {
//1.加載驅動

Class.forName("com.mysql.jdbc.Driver");
//2.獲得鏈接
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
//3.編寫sql語句
String sql ="insert into product values (null,?,?,?)";
//4.預編譯
prepareStatement = connection.prepareStatement(sql);
//5.設置參數
prepareStatement.setString(1, "蘋果");
prepareStatement.setDouble(2, 3.5);
prepareStatement.setObject(3, new Date());
//6.執行
prepareStatement.executeUpdate();

    } catch (ClassNotFoundException | SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally {
        //7.關閉資
        try {
            if(prepareStatement!=null){
                prepareStatement.close();
            }
            if(connection!=null){
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}
@Test
public void testJdbcSelect(){
    PreparedStatement prepareStatement = null;
    Connection connection = null;
    ResultSet executeQuery = null;
    try {
        //1.加載驅動
        Class.forName("com.mysql.jdbc.Driver");
        //2.獲得鏈接
        connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
        //3.編寫sql語句
        String sql ="select * from product where pid=?";
        //4.預編譯
        prepareStatement = connection.prepareStatement(sql);
        //5.設置參數
        prepareStatement.setInt(1, 1);
        //6.執行
        executeQuery = prepareStatement.executeQuery();

        while(executeQuery.next()){
            System.out.println(executeQuery.getInt(1));
            System.out.println(executeQuery.getString(2));
            System.out.println(executeQuery.getDouble(3));
            System.out.println(executeQuery.getDate(4));
        }
    } catch (ClassNotFoundException | SQLException e) {
        e.printStackTrace();
    }finally {
        //7.關閉資
        try {
            if(executeQuery!=null){
                executeQuery.close();
            }
            if(prepareStatement!=null){
                prepareStatement.close();
            }
            if(connection!=null){
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}
 

}
/*
註意jdbc的修改 刪除 添加都除了sql語句都差不多，所以這裏就只寫了一個添加

預編譯不僅能提高性能還能防止sql註入
*/

jdbc鏈接mysql