Upgrading incompatible issue

[SElab2019]

Hi,

The following code snippets throw an incompatible issue when I try to upgrade Gson from 2.2.2 to 2.8.5.

public class TestGson {
	
    public static <T> String convertObjectToString(T t, Class<T> clazz) {
        Gson gson = new GsonBuilder().create();
        try {
            return gson.getAdapter(clazz).toJson(t);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }
}

It works well before, but It throws an error after upgrading:

exception java.io.IOException is never thrown in body of corresponding try statement

Thanks a lot!

[Marcono1234]

In case this is still relevant, could you please test this with the latest Gson version and also provide a complete code example?

[jvirtanen]

This actually looks like an improvement in Gson between 2.2.2 and 2.8.5: in Gson 2.8.5, TypeAdapter<T>#toJson(T value) is no longer declared as throwing IOException. This was implemented in 0328479 and released in Gson 2.4.

[Marcono1234]

Ah thank you for the clarification, I thought the author of this issue meant the error message occurred during runtime, but it was actually a compiler error.

I guess adding back throws IOException now would not be very useful and would also again break source compatibility. Though the assumption that no IOException can occur is actually incorrect (#2172).

Also, let's better not look at the signature of TypeAdapter.fromJson(String) (fromJson(String) throws IOException) from a consistency perspective 🙈