android，输入100后，点击"确认"就崩了

Question

 public class MainActivity extends Activity implements OnClickListener {
    EditText editText;
    Button bt;
    TextView textView,textView1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText=(EditText)findViewById(R.id.edittext);
        bt=(Button)findViewById(R.id.button);
        textView=(TextView)findViewById(R.id.tv1);
        textView1=(TextView)findViewById(R.id.tv2);
        bt.setOnClickListener(this);
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.button:

            String str=editText.getText().toString();
            textView.setText(str+"以内的质数有:");
            textView1.setText("2,3");
            int n=Integer.parseInt(str);
            int i=5;
            int j=2;
            while(i<=n)
            {
                while(j<i)
                {
                    j=2;
                    if(i%j==0)
                        break;
                    if(i-1==j)
                        textView1.append(","+i);
                    j++;
                }
                i++;
            }

            break;
       default:break;
        }
    }
}

Answer 1

anr了，这代码一直循环，还是还主线程。。