Get list of accounts in android

I'm developing an application where I need to see the list of accounts in a user's phone. I have go this code and it seems to work perfectly. The only problem I'm facing is I want to get list of accounts and not just one so how will this be achieved? I'm quite sure that a listview is required but I didn't get any clue as to how can I use that in here.

The code:

package com.example.root.accountspermission;

import android.Manifest;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Patterns;
import android.widget.TextView;
import android.widget.Toast;

import java.util.regex.Pattern;

public class MainActivity extends AppCompatActivity {

    public static final int PERMS_REQUEST_CODE = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.GET_ACCOUNTS) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.GET_ACCOUNTS)) {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            }
        } else {
            //do some stuff
            String email = null;

            Pattern gmailPattern = Patterns.EMAIL_ADDRESS;
            Account[] accounts = AccountManager.get(this).getAccounts();
            for (Account account : accounts) {
                if (gmailPattern.matcher(account.name).matches()) {
                    email = account.name;
                }
            }

            TextView viewEmail = (TextView) findViewById(R.id.email_address_view);
            viewEmail.setText("Email From Device: " + email);
            Toast.makeText(this, "Android Device Registered Email Address: " + email, Toast.LENGTH_LONG).show();
        }

    }
}

Any kind of help would be appreciated.

UPDATE:

Thank you for your answer 'AndiGeeky'. I was able to modify the code a bit, have a look:

import android.Manifest;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Patterns;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;

public class MainActivity extends AppCompatActivity {

    private ListView lv;
    public static final int PERMS_REQUEST_CODE = 1;

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

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.GET_ACCOUNTS) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.GET_ACCOUNTS)) {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            }
        } else {
            //do some stuff
            lv = (ListView) findViewById(R.id.accountsList);
            List<String> emails = new ArrayList<String>();

            Pattern gmailPattern = Patterns.EMAIL_ADDRESS;
            Account[] accounts = AccountManager.get(this).getAccounts();
            for (Account account : accounts) {
                if (gmailPattern.matcher(account.name).matches()) {
                    emails.add(account.name);
                }
            }

            ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,android.R.id.text1,emails);
            lv.setAdapter(adapter);
            //TextView viewEmail = (TextView) findViewById(R.id.email_address_view);
            //viewEmail.setText("Email From Device: " + emails.size());
            Toast.makeText(this, "Android Device Registered Email Address: " + emails.size(), Toast.LENGTH_LONG).show();
        }
    }
}

I was able to print all the accounts in a listview.

Code for XML:

<ListView
        android:id="@+id/accountsList"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintRight_toRightOf="parent" />

Solution

Change your implementation as below:

public class MainActivity extends AppCompatActivity {

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

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.GET_ACCOUNTS) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.GET_ACCOUNTS)) {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.GET_ACCOUNTS}, PERMS_REQUEST_CODE);
            }
        } else {
            //do some stuff
            ArrayList<String> emails = new ArrayList<>();

            Pattern gmailPattern = Patterns.EMAIL_ADDRESS;
            Account[] accounts = AccountManager.get(this).getAccounts();
            for (Account account : accounts) {
                if (gmailPattern.matcher(account.name).matches()) {
                    emails.add(account.name);
                }
            }

            TextView viewEmail = (TextView) findViewById(R.id.email_address_view);
            viewEmail.setText("Email From Device: " + emails.size());
            Toast.makeText(this, "Android Device Registered Email Address: " + emails.get(0), Toast
                    .LENGTH_LONG).show();
        }
    }
}

Your Code:

Here your code just looping through the user accounts and when it follows pattern mentioned just store that account to string and leave other accounts!

Edited Code

I have just stored all user accounts which follows pattern mentioned in code in a list.

Thanks!