How to validate the user login credentials in android using PHP, MySql with the help of json

Question

I am new to android development. I want to do the login verification, using php mysql and json.

I am only taking care of the PHP, MySql and json part.

If t

Answer 1

just follow this code i think its work fine...

$email = isset($_REQUEST['email'])?urldecode($_REQUEST['email']):"";
$passwd= isset($_REQUEST['passwd'])?urldecode($_REQUEST['passwd']):"";
if($email==""||$passwd=="" )
{
$return_data['status'] = 0;

}
else
{
  $user_info="select id from table name WHERE email=$emailAND passwd=$passwd";
    if($user_info)
      {
       $return_data['status'] = 1;
      }
     else
    {
     $return_data['status'] = 0;
    }
}
echo json_encode($return_data);

Answer 2

Your android client must do a Http post to your PHP script, which returns the status code. Your script sees that request as any other post requests. The client receives the result from server, and makes the computation it needs.

Answer 3

I have done this code for my project. and it works fine. Give it a try.

Login2.php

<?php
$un=$_POST['username'];
$pw=$_POST['password'];
//connect to the db

$host="localhost"; // Host name 
$user="root"; // Mysql username 
$pswd=""; // Mysql password 
$db="database_name"; // Database name 
$tbl_name="user_info"; // Table name

$conn = mysql_connect($host, $user, $pswd);
mysql_select_db($db, $conn);
//run the query to search for the username and password the match
//$query = "SELECT * FROM $tbl_name WHERE first_name = '$un' AND password = '$pw'";
$query = "SELECT emp_id FROM $tbl_name WHERE first_name = '$un' AND password = '$pw'";
$result = mysql_query($query) or die("Unable to verify user because : " . mysql_error());
//this is where the actual verification happens
if(mysql_num_rows($result) > 0)
echo mysql_result($result,0);  // for correct login response
else
echo 0; // for incorrect login response
?>

Java Code for Android login.java

take two edittext and button and on button click put this code. delete saveperference method it you dont want to save username , emp_id to entire application.

    @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
                    postParameters.add(new BasicNameValuePair("username", username
                            .getText().toString()));
                    postParameters.add(new BasicNameValuePair("password", password
                            .getText().toString()));
                    // String valid = "1";
                    String response = null;
                    try {
                        // "http://10.0.2.2//Mobile/login2.php"
                        response = CustomHttpClient
                                .executeHttpPost(
                                        "http://10.0.2.2//Mobile/login2.php",
                                        postParameters);
// now in result you will have the response from php file either 0 or 1.                        
result = response.toString();
                        // res = res.trim();
                        result = result.replaceAll("\\s+", "");
                        // error.setText(res);

                        if (!result.equals("0")) {
                            SavePreferences("name", "pass", "emp_id", username
                                    .getText().toString(), password.getText()
                                    .toString());
                            Intent in = new Intent(Login.this, MainScreen.class);

                            // LoadPreferences();
                            error.setText("");

                            startActivity(in);
                        }

                        else
                            error.setText("Incorrect Username or Password");

                    } catch (Exception e) {
                        // un.setText(e.toString());
                    }

                }

CustumHttpClient.java

public class CustomHttpClient {
    /** The time it takes for our client to timeout */
    public static final int HTTP_TIMEOUT = 30 * 1000; // milliseconds

    /** Single instance of our HttpClient */
    private static HttpClient mHttpClient;

    /**
     * Get our single instance of our HttpClient object.
     *
     * @return an HttpClient object with connection parameters set
     */
    private static HttpClient getHttpClient() {
        if (mHttpClient == null) {
            mHttpClient = new DefaultHttpClient();
            final HttpParams params = mHttpClient.getParams();
            HttpConnectionParams.setConnectionTimeout(params, HTTP_TIMEOUT);
            HttpConnectionParams.setSoTimeout(params, HTTP_TIMEOUT);
            ConnManagerParams.setTimeout(params, HTTP_TIMEOUT);
        }
        return mHttpClient;
    }

    /**
     * Performs an HTTP Post request to the specified url with the
     * specified parameters.
     *
     * @param url The web address to post the request to
     * @param postParameters The parameters to send via the request
     * @return The result of the request
     * @throws Exception
     */
    public static String executeHttpPost(String url, ArrayList<NameValuePair> postParameters) throws Exception {
        BufferedReader in = null;
        try {
            HttpClient client = getHttpClient();
            HttpPost request = new HttpPost(url);
            UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters);
            request.setEntity(formEntity);
            HttpResponse response = client.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

            StringBuffer sb = new StringBuffer("");
            String line = "";
            String NL = System.getProperty("line.separator");
            while ((line = in.readLine()) != null) {
                sb.append(line + NL);
            }
            in.close();

            String result = sb.toString();
            return result;
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * Performs an HTTP GET request to the specified url.
     *
     * @param url The web address to post the request to
     * @return The result of the request
     * @throws Exception
     */
    public static String executeHttpGet(String url) throws Exception {
        BufferedReader in = null;
        try {
            HttpClient client = getHttpClient();
            HttpGet request = new HttpGet();
            request.setURI(new URI(url));
            HttpResponse response = client.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

            StringBuffer sb = new StringBuffer("");
            String line = "";
            String NL = System.getProperty("line.separator");
            while ((line = in.readLine()) != null) {
                sb.append(line + NL);
            }
            in.close();

            String result = sb.toString();
            return result;
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}