LogCat - Does not appear [closed]

I'm doing Example5 of cap 3 of the Google Android 3rd book (Ricardo R.Lecheta), where applying a filter to display in the logcat. but it's not coming back to me.

package br.livro.android.cap3;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;


public class Exemplo5 extends Activity {
    private static final String CATEGORIA = "livro";

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        setContentView(R.layout.main);

        // Verbose
        Log.v(CATEGORIA, "log de verbose");

        // Debug
        Log.d(CATEGORIA, "log de debug");

        // Info
        Log.i(CATEGORIA, "log de info");

        // Warn
        Log.w(CATEGORIA, "log de alerta");

        // Error
        Log.e(CATEGORIA, "log de erro", new RuntimeException("teste de erro"));
    }
}