Android Activity回收与操作超时处理

public class ActivityCollector {
  private static List<Activity> activityList = new ArrayList<Activity>();
  public static void addActivity(Activity activity){
    activityList.add(activity);
  }
  public static void removeActivity(Activity activity){
    activityList.remove(activity);
  }

  public static void finishAllButLast(){
    Activity activity = activityList.get(activityList.size()-1);
    removeActivity(activity);

    for (Activity activityItem: activityList){
      if (!activityItem.isFinishing()){
        activityItem.finish();
      }
    }

    activityList.clear();
    activityList.add(activity);
  }

  public static void finishAll(){
    for (Activity activity: activityList){
      if (!activity.isFinishing()){
        activity.finish();
      }
    }

    activityList.clear();
  }
}

public class BaseActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActivityCollector.addActivity(this);
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    ActivityCollector.removeActivity(this);
  }
}

abstract public class TimeOutCheckActivity extends BaseActivity {
  private boolean isLeave = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    pref = getSharedPreferences(Constant.CONFIG_NAME, Context.MODE_PRIVATE);
  }

  /**
   * 回调函数，方便测试
   * @return
  */
  abstract protected String getTag();

  ......省略号......

  /***
   * 当用户使程序恢复为前台显示时执行onResume()方法,在其中判断是否超时.
   */
  @Override
  protected void onResume() {
//    Log.i("Back",getTag() + "，onResume，是否在前台：" + isOnForeground());
    super.onResume();
    if (isLeave) {
      isLeave = false;
      timeOutCheck();
    }
  }

  @Override 
  protected void onStop() {
    super.onStop();
    if (!isOnForeground()){
      if (!isLeave && isOpenALP()) {
        isLeave = true;
        saveStartTime();
      }
    }
  }

  public void timeOutCheck() {
    long endtime = System.currentTimeMillis();
    if (endtime - getStartTime() >= Constant.TIMEOUT_ALP * 1000) {
      Util.toast(this, "超时了,请重新验证");
      String alp = pref.getString(Constant.ALP, null);
      if (alp == null || alp == "") {
      } else {
        Intent intent = new Intent(this, UnlockGesturePasswordActivity.class);
        intent.putExtra("pattern", alp);
        intent.putExtra("login",false); //手势验证，不进行登录验证
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        // 打开新的Activity
        startActivityForResult(intent, Constant.REQ_COMPARE_PATTERN_TIMEOUT_CHECK);
      }
    }
  }

  public void saveStartTime() {
    pref.edit().putLong(Constant.START_TIME, System.currentTimeMillis()).commit();
  }

  public long getStartTime() {
    long startTime = 0;
    try {
      startTime = pref.getLong(Constant.START_TIME, 0);
    }catch (Exception e){
      startTime = 0;
    }
    return startTime;
  }

  /**
   * 程序是否在前端运行,通过枚举运行的app实现。防止重复超时检测多次,保证只有一个activity进入超时检测
   *当用户按home键时，程序进入后端运行，此时会返回false，其他情况引起activity的stop函数的调用，会返回true
   * @return
  */
  public boolean isOnForeground() {
    ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
    String packageName = getApplicationContext().getPackageName();

    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
    if (appProcesses == null)
      return false;

    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
      if (appProcess.processName.equals(packageName)
          && appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) { 
        return true;
      }
    }

    return false;
  }
}

public static final int IMPORTANCE_BACKGROUND = 400//后台 
public static final int IMPORTANCE_EMPTY = 500//空进程 
public static final int IMPORTANCE_FOREGROUND = 100//在屏幕最前端、可获取到焦点 可理解为Activity生命周期的OnResume(); 
public static final int IMPORTANCE_SERVICE = 300//在服务中 
public static final int IMPORTANCE_VISIBLE = 200//在屏幕前端、获取不到焦点可理解为Activity生命周期的OnStart();