Java tutorial
//package com.java2s; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.provider.ContactsContract.PhoneLookup; public class Main { public static int getContactIdFromPhoneNumber(final Context context, final String number) { final Uri uri = Uri.withAppendedPath(PhoneLookup.CONTENT_FILTER_URI, Uri.encode(number)); final String[] projection = { PhoneLookup._ID }; final Cursor c = context.getContentResolver().query(uri, projection, null, null, null); if (c.getCount() > 0) { c.moveToFirst(); return c.getInt(0); } else { return -1; } } private static int getInt(final Cursor cursor, final String field, final int defValue) { if (cursor.getColumnIndex(field) >= 0) { return cursor.getInt(cursor.getColumnIndex(field)); } else { return defValue; } } }