该IF-ELSE语句的内容是什么？

Question

I'm really stuck here and it simply doesn't make any sense to me. Here's what's going on: I have an AsyncTask sending data to a server and retrieving a String response back. The String response can be two things: it can be a message telling the user that he/she is logged in if the credentials entered are correct or it can be a "FALSE" string which I use to display a notification toast to the user and take him/her back to the main activity to retry logging in.

Here is the code snippet:

button.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {    
        String cr = "Placeholder";
        Credential cred = new Credential();

        try { cr = cred.execute().get(); } 
        catch (InterruptedException e) { e.printStackTrace(); } 
        catch (ExecutionException e) { e.printStackTrace(); }
        //tv.setText(cr);

        if (cr == "FALSE") {
            Log.d("Checking in false", cr);
            Toast.makeText(Credentials.this, "Cannot log in: wrong username or password", Toast.LENGTH_LONG).show();
            startActivity(new Intent(Credentials.this, MainActivity.class));
        } else if (cr != "FALSE") {
            Log.d("Checking in true", cr);
            Intent intent = new Intent(Credentials.this, ProfileActivity.class);
            intent.putExtra(INTENT_DATA, cr);
            startActivity(intent);
        }
    }
});

By using the Log.d() static method and looking at the LogCat, I'm sure that the returned value is indeed FALSE if the credentials are wrong (again, it's not a boolean value, just String in all Caps). The funny thing is that the code that gets executed is the "else if" part of the snippet I have posted but it actually logs that the returned string value is FALSE ! Which means (at least to me) that it should have executed the first "if" condition (that is, if (cr == "FALSE") { } ). But no, it keeps executing the "else if" part.

Any ideas?

Answer 1

Use equals for string comparisons.

IE:

WRONG:

if (cr == "FALSE") {

CORRECT:

if (cr.equals("FALSE")) {

Answer 2

Use

if (cr.contentEquals("false") {
    //your code     
} else {
    //your code
}