java - 通过Gson将对象转换为Json时出现OutOfMemory异常

Question

我得到

java.lang.OutOfMemoryError

对于某些用户(并非总是)，当我使用 Gson 将对象列表转换为 JSON 时。请告诉我如何解决这个问题。

@Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if(myList != null && !myList.isEmpty()) {
            //exception at this line
            String myJson = new Gson().toJson(myList, myList.getClass());
            outState.putString(MY_LIST, myJson);
        }
        outState.putInt(NEXT_PAGE, getNextPage());
    }

myList 是我的自定义对象的列表，列表大小为 400kb 到 600kb

Answer 1

这将取决于您的列表的大小。为什么不使用流API https://sites.google.com/site/gson/streaming

更具体一些，例如

public String writeListToJson(List myList) throws IOException {
    ByteArrayOutputStream byteStream =new ByteArrayOutputStream();
    OutputStreamWriter outputStreamWriter=new OutputStreamWriter(byteStream ,"UTF-8");
    JsonWriter writer = new JsonWriter(outputStreamWriter);
    writer.setIndent("  ");
    writer.beginArray();
    Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting().create();
    for (Object o : myList) {
        gson.toJson(o, o.class, writer);
    }
    writer.endArray();
    writer.close();
    return byteStream.toString("UTF-8");
}