We all know android has content provider, and we can access these data with content resolver,

 

1) add permission,

2) getContentResolver

ContentResolver cr = getContentResolver();        Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI,

3) Enumerate and Query

For other data, for example, sms,etc,  it‘s similar, the only different is the uri, have fun! Reference:   1)  2)