$log= $_POST['user'];
$pass=$_POST['password'];

...
 print 1;
...

 public static void setAuthorization(String login, String password) throws IOException {
        URL url = null;
        try {
            url = new URL(strURL);
            System.out.println(strURL);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");
        conn.setDoInput(true);
        conn.setDoOutput(true);
        OutputStream os = conn.getOutputStream();
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));
        writer.write("login="+login+"&password="+password);
        writer.flush();
        writer.close();
        os.close();
        conn.connect();
        BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }

    }

<?php
if (empty($_POST['login']) || empty($_POST['password']))  
{
    echo 0;  
} else {
    $log= $_POST['login'];
   $pass=$_POST['password'];
    
	try {
     $dbh = new PDO('mysql:host=localhost;charset=utf8;dbname=db_sales', $log, $pass);
     $response = $dbh->query("SELECT 1");
    print 1;
    
} catch (PDOException $e) {
    echo 0; //print "Error!: " . $e->getMessage();
   // die();
}
}
?>