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 the user enters the username and password in android app, then it needs to check the user table using PHP and Mysql and it needs to send only the status code like 1 or 0 using json.

If username and password matches then the status = 1 needs to send to the android app coding, else 0.

Status checking process need to be done in Android Coding part.

If status = 1 and I need to redirect to another window in android app .

I have seen lots of tuts and but nothing has helped me.

So, please kindly help me how to send the status from PHP to android app and how to get that status and validate in android.

Answer 1

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();
                }
            }
        }
    }
}