android - 更新到 GooglePlayServices 26.0.2 后，ActivityDetectionBroadcastReceiver 无法编译

Question

这是我的 onReceive 函数:

    @Override
public void onReceive(Context context, Intent intent) {
    ArrayList<DetectedActivity> updatedActivities =
            intent.getParcelableArrayListExtra(Constants.ACTIVITY_EXTRA);
    int type = 0x0;
    Integer confidence = 0;
    Collections.sort(updatedActivities, new Comparator<DetectedActivity>() {
        @Override
        public int compare(DetectedActivity lhs, DetectedActivity rhs) {
            if(lhs.getConfidence() > rhs.getConfidence()){
                return -1;
            }else if(lhs.getConfidence() > rhs.getConfidence()){
                return 1;
            }
            return 0;
        }
    });
    String rawData = "(";
    for (DetectedActivity detectedActivity : updatedActivities){
        if(detectedActivity.getConfidence() >= 25){
            if(type==PSMotionService.unknown || type==PSMotionService.stationary) {
                rawData += detectedActivity.getType() + ":" + detectedActivity.getConfidence() + ",";
                Log.i("", "autopilot type detected activity: " + detectedActivity);
                if (confidence < detectedActivity.getConfidence()) {
                    confidence = detectedActivity.getConfidence();
                }
                if (detectedActivity.getType() == DetectedActivity.STILL) {
                    type |= PSMotionService.stationary;
                } else if (detectedActivity.getType() == DetectedActivity.IN_VEHICLE) {
                    type |= PSMotionService.automotive;
                } else if (detectedActivity.getType() == DetectedActivity.ON_BICYCLE) {
                    type |= PSMotionService.bicycling;
                } else if (detectedActivity.getType() == DetectedActivity.ON_FOOT || detectedActivity.getType() == DetectedActivity.WALKING) {
                    type |= PSMotionService.walking;
                } else if (detectedActivity.getType() == DetectedActivity.RUNNING) {
                    type |= PSMotionService.running;
                } else if (detectedActivity.getType() == DetectedActivity.UNKNOWN) {
                    type |= PSMotionService.unknown;
                }
            }
        }
    }
    rawData += ")";
    Long timestamp = System.currentTimeMillis()/1000;
    Integer confidenceFlag = 0;
    if(confidence >= 25 && confidence < 75){
        confidenceFlag = 1;
    }else if(confidence >=75){
        confidenceFlag = 2;
    }
    Log.i("", "autopilot type is:" + type + "... timestamp: " + timestamp + "....confidence" + confidence + "...confidenceFlag:" + confidenceFlag);
    Log.i("", "autopilot-----------------------------------------------END");
    Motion activity = new Motion(timestamp, type, confidenceFlag);
    Utils.appendLog("NEW MOTION: [" + activity.getTimestamp() + ", " + activity.getType() + ", " + activity.getConfidence() + "]" + rawData, "D", Constants.TRACKER);
    if(PSTrip.getActiveTrip() != null){
        PSMotionService.getInstance(context).motionsTrip.add(activity);
        Log.i("", "autopilot added to trip: size is:" + PSMotionService.getInstance(context).motionsTrip.size());
        if(PSApplicationClass.getInstance().pref.getGeoEnabled(context)) {
            appendMotionActivity(context, type, activity);
        }
    }else{
        Log.i("", "autopilot test to add to buffer");
        appendMotionActivity(context, type, activity);
    }
    Log.i("", "autopilot-----------------------------------------------END AAAAALLLLLLL");
}

我会像这样从 Intent 中提取 DetectedActivity 列表:

        ArrayList<DetectedActivity> updatedActivities =
            intent.getParcelableArrayListExtra(Constants.ACTIVITY_EXTRA);

但现在我遇到了这个问题:

/Users/alinrosu/Workspace/passenger-android/passenger/src/main/java/nl/hgrams/passenger/listeners/ActivityDetectionBroadcastReceiver.java
Error:(31, 51) error: incompatible types: inferred type does not conform to upper bound(s)
inferred: DetectedActivity
upper bound(s): Parcelable
Error:Execution failed for task ':passenger:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

如何在不出现此问题的情况下提取 DetectedActivity 列表？

Answer 1

问题是您正在使用 Java 8 的语言级别设置，这加强了对自动转换的一些限制，而这些限制在 Java 7 及更低版本中是可以的。参见 Why does this Java 8 program not compile?了解更多详情。

我没有什么东西可以用来测试它，所以我不能确定这是否有效，但你可以先尝试转换它:

ArrayList<DetectedActivity> updatedActivities = 
    (ArrayList<DetectedActivity>)intent.getParcelableArrayListExtra(Constants.ACTIVITY_EXTRA);

如果这不起作用，请这样做:

ArrayList<Parcelable> updatedActivities = intent.getParcelableArrayListExtra(Constants.ACTIVITY_EXTRA);

现在，当您使用数组时，您需要强制转换每个元素，如下所示:

for (Parcelable p : updatedActivities) {
    // cast to correct type
    DetectedActivity detectedActivity = (DetectedActivity)p;
    // do whatever with "detectedActivity"...
}