setEnabled() function is not working in if condition

I have some weird case:

package com.example.android.circles_2907;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class SkipActivity extends AppCompatActivity  {
    Button likebtn,dislike;

    @Override
    protected void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.after_skip_scr);


        likebtn=(Button) findViewById(R.id.likebtn) ;
        dislike=(Button) findViewById(R.id.dislike);
        int  i=0;

        TextView counter=(TextView) findViewById(R.id.counter);
        if(counter.getText()=="0") {
            dislike.setEnabled(false);
        } else dislike.setEnabled(true);
}}

In the code - dislike.setEnabled(false); is not working. If i just remove the if condition, the button just disappeared as i need, but why it's don't work in if condition?