Java – how do I send messages from my android app to specific contacts via WhatsApp?

I'm developing an Android application. I need to send messages to specific contacts of WhatsApp. I've tried this Code:

Uri mUri = Uri.parse("smsto:+999999999");
Intent mIntent = new Intent(Intent.ACTION_SENDTO, mUri);
mIntent.setPackage("com.whatsapp");
mIntent.putExtra("sms_body", "The text goes here");
mIntent.putExtra("chat",true);
startActivity(mIntent);

The problem is that although the contact is selected, the parameter "sms_body" is not received on WhatsApp

resolvent:

Try using intent.extra_ Text instead of SMS_ Body as an additional key. According to WhatsApp's documentation, this is what you must use

An example of their website:

Intent sendIntent = new Intent();
sendIntent.setAction(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send.");
sendIntent.setType("text/plain");
startActivity(sendIntent);

Their example uses intent. Action_ Send instead of intent.action_ SendTo, so I'm not sure whether WhatsApp supports sending directly to contacts through the intention system. Some quick tests should let you determine