官方文档：https://developer.android.google.cn/reference/android/media/MediaPlayer

运行截图： 

 主布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="新春乐-纯音乐"
        android:textSize="40sp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp">

        <Button
            android:id="@+id/start"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="开始"
            android:textAllCaps="false"
            android:textSize="25sp" />

        <Button
            android:id="@+id/pause"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="暂停"
            android:textAllCaps="false"
            android:textSize="25sp" />
    </LinearLayout>


</LinearLayout>

主类：

/***
 * 该Demo是演示MediaPlayer播放网络音频
 */
public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button start;
    private Button pause;

    private MediaPlayer mediaPlayer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        initMediaPlayer();
    }

    private void initMediaPlayer() {
        try {
            mediaPlayer.setDataSource("http://www.ytmp3.cn/down/57799.mp3");
            mediaPlayer.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void init() {
        start = findViewById(R.id.start);
        pause = findViewById(R.id.pause);
        start.setOnClickListener(this);
        pause.setOnClickListener(this);
        mediaPlayer = new MediaPlayer();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.start:
                if (!mediaPlayer.isPlaying()) {
                    mediaPlayer.start();
                }
                break;
            case R.id.pause:
                if (mediaPlayer.isPlaying()) {
                    mediaPlayer.pause();
                }
                break;
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mediaPlayer != null) {
            mediaPlayer.stop();
            mediaPlayer.release();
        }
    }
}
//音乐地址：http://www.ytmp3.cn/down/57799.mp3

不要忘记在Manifest.xml里添加网络权限：

    <uses-permission android:name="android.permission.INTERNET" />