<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/images"
android:orientation="vertical"
tools:context="com.altavista.dc.serviceprovider.MainActivity"
android:weightSum="1"
>
    <TextView
        android:layout_width="wrap_content"
        android:text="Username"
        android:textSize="18dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="125dp" />
    <EditText
        android:id="@+id/etUsername"
        android:layout_width="match_parent"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:layout_height="wrap_content" />

    <TextView
        android:layout_width="wrap_content"
        android:text="Password"
        android:textSize="18dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"/>
    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:inputType="textPassword"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/bLogin"
        android:layout_width="match_parent"
        android:text="Login"
        android:textSize="18dp"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="10dp"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
    <TextView
        android:id="@+id/tvForgotlink"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Forgot password?"
        android:textStyle="bold"
        android:layout_marginStart="50dp"
        />
    <TextView
        android:id="@+id/tvRegisterlink"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Register here"
        android:textStyle="bold"
        android:layout_marginStart="50dp"/>

    </LinearLayout>

import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;


import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements
View.OnClickListener{

Button bLogin;
EditText etUsername,etPassword;
TextView tvRegisterlink,tvForgotlink;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    etUsername=(EditText)findViewById(R.id.etUsername);
    etPassword=(EditText)findViewById(R.id.etPassword);

    bLogin=(Button)findViewById(R.id.bLogin);


    bLogin.setOnClickListener(this);
    tvRegisterlink.setOnClickListener(this);

}


@Override
public void onClick(View v) {

    String u=etUsername.getText().toString();
    String p=etPassword.getText().toString();
    String url="http://";

    JSONObject obj2=new JSONObject();
    try {
        obj2.put("email",u);
        obj2.put("saltedPassword",p);

    } catch (JSONException e) {
        e.printStackTrace();
    }


    switch (v.getId()) {

        case R.id.bLogin:


            try {
                JSONObject returnVal=new JSONObject(ConnectionHelper.post(obj2, url));
                Boolean val= returnVal.getBoolean("response_bool");

                if(val){
                   startActivity(new Intent(this,Home.class));
                }else{
                    Toast.makeText(getApplicationContext(), "Username or password incorrect", Toast.LENGTH_SHORT).show();
                }

            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }

            break;
        case R.id.tvRegisterlink:
            startActivity(new Intent(this,Register.class));
            break;


    }

}

package com.altavista.dc.serviceprovider;

import android.app.Activity;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;


public class ConnectionHelper {

public static String post(JSONObject json, String url) throws IOException, JSONException {

    URL obj = new URL(url);
    HttpURLConnection con = (HttpURLConnection) obj.openConnection();

    //add request header
    con.setRequestMethod("POST");
    con.setRequestProperty("Content-Type", "application/json");



    // Send post request
    con.setDoOutput(true);
    DataOutputStream wr = new DataOutputStream(con.getOutputStream());
    wr.writeBytes(json.toString());
    wr.flush();
    wr.close();

    if (con.getResponseCode() == 200) {

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        return response.toString();

    } else {

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("response", con.getResponseCode());
        jsonObject.put("message", "error");


        return jsonObject.toString();
    }


}