Does calling .body() from response Retrofit in try body might returns null?

Question

I have simple snippet code as below:

Sub sub = null;

try {
    Response<Sub> response = MyRestApi.getInstance().getSub().execute();
    sub = response.body(); // Does variable response is always non null?
} catch (IOException e) {
    e.printStackTrace();
}

//
// ... further operations on sub
// 

All that I want to know is, can I call safely .body() on response in try body?

I've tried to preview my method information .getSub() by calling CTRL-Q in Android Studio but I got the only line

Inferred annotations: @org.jetbrains.annotations.NotNull

I believe it should be enough to convince me about that but I had to ask and be 100% sure.

Answer 1

如果响应不成功，则它可以为null。

Answer 2

It might be null, even when request is successful, as described on w3c:

"Response data Additional information may follow, in the format of a MIME message body. The significance of the data depends on the status code.

The Content-Type used for the data may be any Content-Type which the client has expressed its ability to accept, or text/plain, or text/html. That is, one can always assume that the client can handle text/plain and text/html."

reference: https://www.w3.org/Protocols/HTTP/Response.html

In Retrofit, the body method is defined as Nullable

@Nullable public T body() The deserialized response body of a successful response.

https://square.github.io/retrofit/2.x/retrofit/retrofit2/Response.html