Java connects MySQL database with JDBC

First Class:

Package dina.web.test;

Import java.sql.*;

public class DBHelper {
public static final String DRIVER = "Com.mysql.jdbc.Driver";
public static final String URL = "Jdbc:mysql://58.215.50.62:3307/iov";
public static final String USER = "Iov_user";
public static final String PASSWORD = "2wsx3edc";

public Connection conn = null;
public PreparedStatement PST = NULL;

Public dbhelper (String sql) {
try {
Class.forName (DRIVER);
conn = Drivermanager.getconnection (URL, USER, PASSWORD);
PST = conn.preparestatement (SQL);
} catch (Exception e) {
E.printstacktrace ();
}
}

public void Close () {
try {
if (PST! = null) {
This.pst.close ();
}

} catch (Exception e) {
E.printstacktrace ();
}
try {
IF (conn! = null) {
This.conn.close ();
}
} catch (Exception e) {
E.printstacktrace ();
}

}
}

A second class:

Package dina.web.test;

Import java.sql.Connection;
Import Java.sql.DriverManager;
Import Java.sql.ResultSet;
Import java.sql.SQLException;
Import java.sql.Statement;

public class Sqlexcute {

static DBHelper db = null;
static String sql = NULL;
static ResultSet rs = null;

public static void Main (string[] args) {
sql = "SELECT * from Sys_user where username= ' 15020151106 '";
db = new dbhelper (SQL);
try {
Rs=db.pst.executequery ();
while (Rs.next ()) {

SYSTEM.OUT.PRINTLN ("Account Number:" +rs.getstring (3));
System.out.println ("Name:" +rs.getstring (4));
}
Rs.close ();
Db.close ();

} catch (SQLException e) {
E.printstacktrace ();
}
}

}

Java connects MySQL database with JDBC