Indexoutofbounds：访问另一个类变量 [英] Indexoutofbounds: accessing another class variable

问题描述

我的MainActivity.class上的代码出现了IndexOutOfBounds异常。



索引：0大小：0



我试图打印出我收到的坐标，它显示了我需要的实际坐标。当我从另一个类访问变量时，我什么都没得到。似乎有什么问题？



我尝试过的事情：

I get IndexOutOfBounds exception on my code on my MainActivity.class.

Index: 0 Size: 0

I tried to print out the coordinates I am receiving and it shows the actual coordinates I need. When I access the variable from another class, I am getting nothing. What seems to be the problem?

What I have tried:

I was trying to access coordinates from my ArrayList from Sample.class using:

This is my MainActivity.class

    public void onMapReady(GoogleMap googleMap) {

        mMap = googleMap;
        mMap.setMinZoomPreference(15.0f);
        mMap.setMaxZoomPreference(20.0f);
        mMap.setOnMapClickListener(this);;

        LatLng latLng = new LatLng(14.397420, 121.033051);
        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));


        double lat = smsReceiver.locationcoords.get(0);
        double lon = smsReceiver.locationcoords.get(1);


            LatLng geofencePos = new LatLng(lat,lon);
            geofenceMarker = mMap.addMarker(new MarkerOptions()
                .position(geofencePos));

    }
This is my SmsReceiver.class where I am getting the coordinates. I printed the coordinates and it displays the coordinates I am receiving.

ArrayList locationcoords = new ArrayList(); //variable set on public

public void sendDataToFirebase(SmsMessage sms, Context context) {

FirebaseApp.initializeApp(context);
databaseLocation = FirebaseDatabase.getInstance().getReference("smsdata");

String senderNumber = sms.getOriginatingAddress();
String mydate = java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
String message = sms.getMessageBody();
String[] separatedSMS = message.split("\\s+");
String needHelp = "I NEED HELP";


    DatabaseReference mRef = databaseLocation.push();
    Double latitudedb = Double.parseDouble(separatedSMS[1]);
    Double longitudedb = Double.parseDouble(separatedSMS[3]);


    HashMap<String, Double> coordinates = new HashMap<String, Double>();
    coordinates.put("latitude", latitudedb);
    coordinates.put("longitude", longitudedb);
    mRef.setValue(coordinates);

    locationcoords.add(latitudedb);
    locationcoords.add(longitudedb);

    double lat = locationcoords.get(0);
    double lon = locationcoords.get(1);
    System.out.println(lat);
    System.out.println(lon);




}

推荐答案

我们无法帮助你有 - 我们无法访问你的数据。

索引越界意味着：提供访问数组的值超出了该数组的范围 - 无论是负数还是更高大于或等于数组中元素的数量。

但是我们不知道哪个方法会抛出错误，或者你传递给它的参数值是什么。



所以，这取决于你。

幸运的是，你有一个工具可以帮助你找到正在发生的事情：调试器。你如何使用它取决于你的编译器系统，但是一个快速的谷歌用于你的IDE名称和调试器应该给你你需要的信息。



放一个断点在函数的第一行，并通过调试器运行代码。然后查看您的代码，并查看您的数据并找出手动应该发生的事情。然后单步执行每一行检查您预期发生的情况正是如此。如果不是，那就是当你遇到问题时，你可以回溯（或者再次运行并仔细观察）以找出原因。


对不起，但我们不能为你做到这一点 - 时间让你学习一门新的（非常非常有用的）技能：调试！

We can't help you with that - we have no access to your data.
"Index out of bounds" means just that: the value supplied to access an array is outside the bounds of that array - either negative, or greater than or equal to the number of elements in the array.
But we have no idea which method is throwing the error, or what the parameter values you are passing to it are.

So, it's going to be up to you.
Fortunately, you have a tool available to you which will help you find out what is going on: the debugger. How you use it depends on your compiler system, but a quick Google for the name of your IDE and "debugger" should give you the info you need.

Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn't, that's when you have a problem, and you can back-track (or run it again and look more closely) to find out why.

Sorry, but we can't do that for you - time for you to learn a new (and very, very useful) skill: debugging!

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