read and write data with GSON

Question

I am struggling to find a good example on how to read and write data in my android app using GSON. Could someone please show me or point me to a good example? I am using thi

Answer 1

You can also do this entirely with streams and avoid an intermediate object:

Vector v;

// This should be reused, so private static final
Gson gson = new GsonBuilder().create();

// Read from file:
try (InputStream fileIn = context.openFileInput("myfile.txt", Context.MODE_PRIVATE);
     BufferedInputStream bufferedIn = new BufferedInputStream(fileIn, 65536);
     Reader reader = new InputStreamReader(bufferedIn, StandardCharsets.UTF_8)) {
    gson.fromJson(reader, Vector.class);
}

v = new Vector(10.0f, 20.0f);

// Write to file
try (OutputStream fileOut = context.openFileOutput(filename, Context.MODE_PRIVATE);
     OutputStream bufferedOut = new BufferedOutputStream(fileOut, 65536);
     Writer writer = new OutputStreamWriter(bufferedOut)) {
    gson.toJson(v, writer);
}

Choose buffer sizes appropriately. 64k is flash-friendly, but silly if you only have 1k of data. try-with-resources might also not be supported by some versions of Android.