给出电子邮件地址查询Android联系人的快速有效方法

Question

I am looking for a fast & efficient way to query the Android contacts given an email address (basically, given an email address I want to find the matching contact if it exists). Currently I have a double While loop and it's probably the most inefficient way to accomplish this.

I imagine that I have to do a custom SQLite join query, but I am unfamiliar with how to do this. Any help or pointers from other users would be appreciated!

Answer 1

There is a way to get the needed details without querying the second cursor. Since the ContentProvider knows how to join the tables, using the projection parameter you can request columns from join tables as well.

So the code might look like this:

Cursor cursor = null;
try {
    //Filter by email address first.
    final String[] projection = new String[] { 
                ContactsContract.CommonDataKinds.Email.CONTACT_ID, 
                ContactsContract.CommonDataKinds.Email.DATA,
                ContactsContract.CommonDataKinds.Email.DISPLAY_NAME_PRIMARY,
                ContactsContract.CommonDataKinds.Email.IS_PRIMARY };

    final String selection = ContactsContract.CommonDataKinds.Email.DATA + "=? and "
                + ContactsContract.CommonDataKinds.Email.IS_PRIMARY+"=1";

    final String[] selectionArgs = new String[] { email };

    cursor = context.getContentResolver().query(ContactsContract.CommonDataKinds.Email.CONTENT_URI, projection, selection, selectionArgs, null);

    if (cursor.moveToFirst()) {
        long contactId = cursor.getLong(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.CONTACT_ID));
        String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.DISPLAY_NAME_PRIMARY));

        // Do something with contactId and displayName
    }
} finally {
    if (cursor!=null) cursor.close();
}

So DISPLAY_NAME_PRIMARY is a column that is joined automatically by the ContentProvider. Not the use of IS_PRIMARY to make sure we get a primary contact raw data and not all data.

Answer 2

After a little bit more research, there is no contract that handles this type of request and you can't do any custom SQL query on any DB that you don't own. I have come up with the best solution that I could. Please comment on this and let me know if there is a way to make this perform any better/faster/efficient.

String incomingEmail = [EMAIL_WE_ARE_SEARCHING_FOR]...
long contactID = -1;
//Filter by email address first.
final String[] emailProjection = new String[]{ContactsContract.CommonDataKinds.Email.CONTACT_ID, 
    ContactsContract.CommonDataKinds.Email.DATA};
final String emailSelection = ContactsContract.CommonDataKinds.Email.DATA + "=?";
final String[] emailSelectionArgs = new String[]{incomingEmail};
final String emailSortOrder = null;
Cursor emailCursor = context.getContentResolver().query(
        ContactsContract.CommonDataKinds.Email.CONTENT_URI, 
        emailProjection,
        emailSelection, 
        emailSelectionArgs, 
        emailSortOrder);
if(emailCursor.moveToFirst()){
    contactID = emailCursor.getLong(emailCursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.CONTACT_ID)); 
    //Query the specific contact if found.
    final String[] projection = new String[]{ContactsContract.Contacts._ID, 
        ContactsContract.Contacts.DISPLAY_NAME, 
        ContactsContract.Contacts.PHOTO_ID, 
        ContactsContract.Contacts.LOOKUP_KEY};
    final String selection = ContactsContract.Contacts._ID + "=?";
    final String[] selectionArgs = new String[]{String.valueOf(contactID)};
    final String sortOrder = null;
    Cursor contactCursor = context.getContentResolver().query(
            ContactsContract.Contacts.CONTENT_URI,
            projection, 
            selection, 
            selectionArgs, 
            sortOrder);             
    if(contactCursor.moveToFirst()){
        contactName = contactCursor.getString(contactCursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
        String photoIDTmp = contactCursor.getString(contactCursor.getColumnIndex(ContactsContract.Contacts.PHOTO_ID)); 
        if(photoIDTmp != null){
            photoID = Long.parseLong(photoIDTmp);
        }
        lookupKey = contactCursor.getString(contactCursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
    }
    contactCursor.close();      
}else{
    emailCursor.close();
    return null;                
}
emailCursor.close();
//Return Contact ID, Contact Name, Contact Photo, Etc.

Thanks!