安卓

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

import com.hanqi.test2.R;

/**
 * Created by 吴仪 on 2016/3/16.
 */
public class Activity2 extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.Activity2
        );
        System.out.print("这是第一个");
        Log.d("test", "Log的输出信息");
        Log.w("test", "Log的输出信息");
        Log.e("test", "Log的输出信息");
        Log.i("test", "Log的输出信息");
        Log.v("test", "Log的输出信息");
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="你好"

        />




</LinearLayout>