I have tried to fix this json program but always have problem in this case, this program can't output data to database and i think the problem is in java mainactivity. But until now I still don't know where the problem is.
this is my ShaperedPrefManager
public class SharedPrefManager {
//the constants
private static final String SHARED_PREF_NAME = "simplifiedcodingsharedpref";
private static final String KEY_USERNAME = "keyusername";
private static final String KEY_ID = "keyid";
private static SharedPrefManager mInstance;
private static Context mCtx;
private SharedPrefManager(Context context) {
mCtx = context;
}
public static synchronized SharedPrefManager getInstance(Context context) {
if (mInstance == null) {
mInstance = new SharedPrefManager(context);
}
return mInstance;
}
//method to let the user login
//this method will store the user data in shared preferences
public void userLogin(user user) {
SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt(KEY_ID, user.getId());
editor.putString(KEY_USERNAME, user.getUsername());
editor.apply();
}
//this method will checker whether user is already logged in or not
public boolean isLoggedIn() {
SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
return sharedPreferences.getString(KEY_USERNAME, null) != null;
}
//this method will give the logged in user
public user getUser() {
SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
return new user(
sharedPreferences.getInt(KEY_ID, -1),
sharedPreferences.getString(KEY_USERNAME, null)
);
}
//this method will logout the user
public void logout() {
SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.clear();
editor.apply();
mCtx.startActivity(new Intent(mCtx, LoginActivity.class));
}
}
this activity main
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.apbProject.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:orientation="vertical"
android:padding="10dp">
<EditText
android:id="@+id/editTextUsername"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:hint="Username"
android:inputType="text" />
<EditText
android:id="@+id/editTextPassword"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:fontFamily="sans-serif"
android:hint="Password"
android:inputType="textPassword" />
<Button
android:id="@+id/buttonRegister"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:text="Register" />
<TextView
android:id="@+id/textViewLogin"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:text="Already Registered?\nLogin Here"
android:textAlignment="center"
android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />
</LinearLayout>
<ProgressBar
android:visibility="gone"
android:id="@+id/progressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
</RelativeLayout>
and this my mainactivity java
package com.example.apbProject;
import android.content.Intent;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.example.registeractivity.R;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
EditText editTextUsername, editTextEmail, editTextPassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//if the user is already logged in we will directly start the profile activity
if (SharedPrefManager.getInstance(this).isLoggedIn()) {
finish();
startActivity(new Intent(this, MonitoringActivity.class));
return;
}
editTextUsername = (EditText) findViewById(R.id.editTextUsername);
editTextPassword = (EditText) findViewById(R.id.editTextPassword);
findViewById(R.id.buttonRegister).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//if user pressed on button register
//here we will register the user to server
registerUser();
}
});
findViewById(R.id.textViewLogin).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//if user pressed on login
//we will open the login screen
finish();
startActivity(new Intent(MainActivity.this, LoginActivity.class));
}
});
}
private void registerUser() {
final String username = editTextUsername.getText().toString().trim();
final String password = editTextPassword.getText().toString().trim();
//first we will do the validations
if (TextUtils.isEmpty(username)) {
editTextUsername.setError("Please enter username");
editTextUsername.requestFocus();
return;
}
if (TextUtils.isEmpty(password)) {
editTextPassword.setError("Enter a password");
editTextPassword.requestFocus();
return;
}
//if it passes all the validations
class RegisterUser extends AsyncTask<Void, Void, String> {
private ProgressBar progressBar;
@Override
protected String doInBackground(Void... voids) {
//creating request handler object
RequestHandler requestHandler = new RequestHandler();
//creating request parameters
HashMap<String, String> params = new HashMap<>();
params.put("username", username);
params.put("password", password);
//returing the response
return requestHandler.sendPostRequest(URLs.URL_REGISTER, params);
}
@Override
protected void onPreExecute() {
super.onPreExecute();
//displaying the progress bar while user registers on the server
progressBar = (ProgressBar) findViewById(R.id.progressBar);
progressBar.setVisibility(View.VISIBLE);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
//hiding the progressbar after completion
progressBar.setVisibility(View.GONE);
try {
//converting response to json object
JSONObject obj = new JSONObject(s);
//if no error in response
if (!obj.getBoolean("error")) {
Toast.makeText(getApplicationContext(), obj.getString("message"), Toast.LENGTH_SHORT).show();
//getting the user from the response
JSONObject userJson = obj.getJSONObject("user");
//creating a new user object
user user = new user(
userJson.getInt("id"),
userJson.getString("username")
);
//storing the user in shared preferences
SharedPrefManager.getInstance(getApplicationContext()).userLogin(user);
//starting the profile activity
finish();
startActivity(new Intent(getApplicationContext(), LoginActivity.class));
} else {
Toast.makeText(getApplicationContext(), "Some error occurred", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
//executing the async task
RegisterUser ru = new RegisterUser();
ru.execute();
}
}
and this is my Api.php
lang-php
<?php
require_once 'DbConnect.php';
$response = array();
if(isset($_GET['apicall'])){
switch($_GET['apicall']){
case 'signup':
if(isTheseParametersAvailable(array('username','password',))){
$username = $_POST['username'];
$password = $_POST['password'];
$stmt = $conn->prepare("SELECT id FROM users WHERE username = ?");
$stmt->bind_param("s", $username);
$stmt->execute();
$stmt->store_result();
if($stmt->num_rows > 0){
$response['error'] = true;
$response['message'] = 'User already registered';
$stmt->close();
}else{
$stmt = $conn->prepare("INSERT INTO users (username, password) VALUES (?, ?)");
$stmt->bind_param("ss", $username, $password);
if($stmt->execute()){
$stmt = $conn->prepare("SELECT id, id, username FROM users WHERE username = ?");
$stmt->bind_param("s",$username);
$stmt->execute();
$stmt->bind_result($userid, $id, $username);
$stmt->fetch();
$user = array(
'id'=>$id,
'username'=>$username,
);
$stmt->close();
$response['error'] = false;
$response['message'] = 'User registered successfully';
$response['user'] = $user;
}
}
}else{
$response['error'] = true;
$response['message'] = 'required parameters are not available';
}
break;
case 'login':
if(isTheseParametersAvailable(array('username', 'password'))){
$username = $_POST['username'];
$password = md5($_POST['password']);
$stmt = $conn->prepare("SELECT id, username FROM users WHERE username = ? AND password = ?");
$stmt->bind_param("ssss",$username, $password);
$stmt->execute();
$stmt->store_result();
if($stmt->num_rows > 0){
$stmt->bind_result($id, $username);
$stmt->fetch();
$user = array(
'id'=>$id,
'username'=>$username,
);
$response['error'] = false;
$response['message'] = 'Login successfull';
$response['user'] = $user;
}else{
$response['error'] = false;
$response['message'] = 'Invalid username or password';
}
}
break;
default:
$response['error'] = true;
$response['message'] = 'Invalid Operation Called';
}
}else{
$response['error'] = true;
$response['message'] = 'Invalid API Call';
}
echo json_encode($response);
function isTheseParametersAvailable($params){
foreach($params as $param){
if(!isset($_POST[$param])){
return false;
}
}
return true;
}
?>
This my error message:
