lyubomyr-shaydariv
commented
4 years ago Despite it looks like Gson 2.8.2 seems to have changed the way it interprets numbers, you should not serialize/deserialize classes you don't control. See these for more information: #1573, #1613, #1660.
What you should do is:
private static final Gson gson = new GsonBuilder()
.registerTypeAdapterFactory(new TypeAdapterFactory() {
@Override
@Nullable
public <T> TypeAdapter<T> create(final Gson gson, final TypeToken<T> typeToken) {
if ( !Range.class.isAssignableFrom(typeToken.getRawType()) ) {
return null;
}
final Type typeArgument = ((ParameterizedType) typeToken.getType()).getActualTypeArguments()[0];
@SuppressWarnings("unchecked")
final TypeAdapter<Comparable<?>> elementTypeAdapter = (TypeAdapter<Comparable<?>>) gson.getDelegateAdapter(this, TypeToken.get(typeArgument));
final TypeAdapter<Range<? extends Comparable<?>>> rangeTypeAdapter = new TypeAdapter<Range<? extends Comparable<?>>>() {
@Override
public void write(final JsonWriter jsonWriter, final Range<? extends Comparable<?>> range)
throws IOException {
// TODO add from/to support?
jsonWriter.beginObject();
jsonWriter.name("v1");
elementTypeAdapter.write(jsonWriter, range.v1);
jsonWriter.name("v2");
elementTypeAdapter.write(jsonWriter, range.v2);
jsonWriter.endObject();
}
@Override
public Range<? extends Comparable<?>> read(final JsonReader jsonReader)
throws IOException {
// TODO add from/to support?
jsonReader.beginObject();
@Nullable
Comparable<?> v1 = null;
@Nullable
Comparable<?> v2 = null;
while ( jsonReader.hasNext() ) {
switch ( jsonReader.nextName() ) {
case "v1":
v1 = elementTypeAdapter.read(jsonReader);
break;
case "v2":
v2 = elementTypeAdapter.read(jsonReader);
break;
default:
// ignore the rest
jsonReader.skipValue();
break;
}
}
if ( v1 == null || v2 == null ) {
throw new IllegalArgumentException("Insufficient range: " + v1 + ", " + v2);
}
@SuppressWarnings({ "unchecked", "rawtypes" })
final Range<? extends Comparable<?>> range = new Range(v1, v2);
return range;
}
}
.nullSafe();
@SuppressWarnings("unchecked")
final TypeAdapter<T> castRangeTypeAdapter = (TypeAdapter<T>) rangeTypeAdapter;
return castRangeTypeAdapter;
}
})
.create();The type adapter will pass the following test:
final JsonElement el = JsonParser.parseString("{\"from\":1,\"to\":50,\"v1\":1,\"v2\":50}");
System.out.println("el: " + el);
final Range<Integer> range = gson.fromJson(el, rangeOfIntegerType);
System.out.println("Range: " + range);
Assertions.assertEquals(new Range<>(1, 50), range);
System.out.println(gson.toJson(new Range<>(1, 50), rangeOfIntegerType));
Aladdill
sindilevich
Marcono1234
Hi, My company used till recently version 2.1, while working on a certain feature, we found, that one of bugs in 2.1 prevent from us creating the feature, so we upgraded to version 2.8.6. after upgrade feature worked well, but one of our POJOs was parsed differently. After some investigation we found, that parsing still works fine in version 2.7. Attached a test that will pass on 2.7 and fail on 2.8.6. Thanks.
JsonParsingTest.zip