Android跟踪函数消耗时间

public class TimeMonitorManager {
    private static final String TAG = "TimeMonitorManager";

    private HashMap<String, Long> mTimeTagMap = new HashMap<>();
    private long mStartTime = 0;
    private static volatile TimeMonitorManager mMonitorManager;
    
    private TimeMonitorManager() {

    }

    public static TimeMonitorManager getInstance() {
        if (mMonitorManager == null) {
            synchronized (TimeMonitorManager.class) {
                if (mMonitorManager == null) {
                    mMonitorManager = new TimeMonitorManager();
                }
            }
        }
        return mMonitorManager;
    }

    /**
     * 开始监听.
     */
    public void startMonitor() {
        if (mTimeTagMap.size() > 0) {
            mTimeTagMap.clear();
        }

        mStartTime = System.currentTimeMillis();

    }


    /**
     * 结束监听.
     * @param tag 所要打印的tag.
     */
    public void endMonitor(String tag) {
        if (mTimeTagMap.get(tag) != null) {
            mTimeTagMap.remove(tag);
        }

        long time = System.currentTimeMillis() - mStartTime;
        mTimeTagMap.put(tag, time);
        showData();
    }

    private void showData() {
        if (mTimeTagMap.size() <= 0) {
            return;
        }

        for (String tag: mTimeTagMap.keySet()
             ) {
            long time = mTimeTagMap.get(tag);
            Log.d(TAG, tag + ": " + time);
        }
    }

}

用法举例

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TimeMonitorManager.getInstance().startMonitor();
        setContentView(R.layout.activity_main);
        TimeMonitorManager.getInstance().endMonitor(TAG + " onCreate setContentView");
    }