This helper class allow to fetch the list of all contact in android phone. It allow user to searh list of contact from name (query) as input.

ContactHelper.java

package com.beatme.app.util;

import android.content.Context;
import android.database.Cursor;
import android.provider.ContactsContract;

import com.beatme.app.service.model.ContactModel;

import java.util.ArrayList;
import java.util.List;

public final class ContactHelper {

    private static List<ContactModel> contactList = new ArrayList<>();

    //If no query is provided, all the contacts will be fetched
    public static List<ContactModel> readContacts(Context context, String query) {
        contactList.clear();
        String[] projection = {ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME, ContactsContract.CommonDataKinds.Phone.NUMBER, ContactsContract.CommonDataKinds.Email.ADDRESS};
        Cursor cursor;
        if (query == null || query.equals("")) {

            cursor = context.getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, projection, null, null, ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " ASC ");
        } else {

            String[] mQuery = {"%"+ query + "%"};

            cursor = context.getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, projection, ContactsContract.Contacts.DISPLAY_NAME + " LIKE ? OR " + ContactsContract.CommonDataKinds.Phone.NUMBER + " LIKE ? ", mQuery, ContactsContract.Contacts.DISPLAY_NAME + " ASC ");
        }

        if (cursor != null && cursor.getCount() > 0) {
            while (cursor.moveToNext()) {
                String name = cursor.getString(0);
                String phone = cursor.getString(1);
                String email = cursor.getString(2);
                if (!(phone == null || phone.equals(""))) {
                    contactList.add(new ContactModel(name,email,phone));
                }
            }
            cursor.close();
        }
        return contactList;
    }

    public static String formatPhone(String phone){
        phone = phone.replaceAll("\\s","");
        if(phone.length()==10){
            phone = "+91"+phone;
        }else if(phone.length()==11){
            phone = "+91"+phone.substring(1);
        }
        return phone;
    }

}