OutOfMemory Error in ArrayList. Android

问题

I am working on http get request on android.

I receive a huge amount of json data from server, a string is unable to handle or store that data and getting OutOfMemory Exception.

Then I tried to save it in arrayList which can store a maximum of Integer.Maximum value. but it is getting OutOfMemory exception while storing at ~8970 location.

Here is my link which has json data.

http://ec2-50-19-105-251.compute-1.amazonaws.com/ad/Upload/getitemlist10122013035042.txt

here is my code:

ArrayList<String> newarr = new ArrayList<String>();
    try {

        URL url = new URL(urlFilePath);
        HttpURLConnection urlConnection = (HttpURLConnection) url
                .openConnection();

        urlConnection.setRequestMethod("GET");
        // urlConnection.setDoOutput(true);

        // connect
        urlConnection.connect();

        // Stream used for reading the data from the internet
        InputStream inputStream = urlConnection.getInputStream();

        // create a buffer...
        byte[] buffer = new byte[1024];
        int bufferLength = 0;
        int check;
        while ((bufferLength = inputStream.read(buffer)) > 0) {
            String decoded = new String(buffer, 0, bufferLength);
            newarr.add(decoded);    // OutOfMemory Exception.   
        }

        fileOutput.close();
        buffer = null;
        inputStream.close();
        String path = file.getAbsolutePath();
        return path;
    } catch (final MalformedURLException e) {
        e.printStackTrace();
        return "";
    } catch (final IOException e) {
        e.printStackTrace();
        return "";
    } catch (final Exception e) {
        System.out.println("EXCEPTION:: " + e.getMessage());
        e.printStackTrace();
        return "";
    }

回答1:

You need to process the stream directly instead of storing it as a String. Look at the Gson Stream Reader as an example:

public List<Message> readJsonStream(InputStream in) throws IOException {
    JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8"));
    List<Message> messages = new ArrayList<Message>();
    reader.beginArray();
    while (reader.hasNext()) {
        Message message = gson.fromJson(reader, Message.class);
        messages.add(message);
    }
    reader.endArray();
    reader.close();
    return messages;
}

You can think of the List here as the parsed result. You could also use the list from whatever ListAdapter you are using if you want to display it.

回答2:

the maximum capacity of an ArrayList (or any kind of list whatsoever) is limited only by the amount of memory the JVM has available.

U can use BufferedReader, or maybe a Scanner instead of String.

Else if u still want to use String then try to increase the JVM.As far as i know there is no way of controlling the heap size at runtime.

It may not be necessary though: you can provide a minimum and maximum heap size with the -Xms and -Xmx switches respectively. (eg -Xms128m -Xmx512m) The jvm will manage the actual heap size within these bounds.

Try to set the limit according to your usage

For more refference try to get some idea from

http://www.coderanch.com/t/614644/Performance/java/Arraylist-heapsize-memory-error

来源：https://stackoverflow.com/questions/20519858/outofmemory-error-in-arraylist-android

标签

android