How to interpret “public T readObjectData(… Class type)” in Java?

Question

I have this Java code.

public  T readObjectData(ByteBuffer buffer, Class type) {
...
T retVal = (T) summaries;
return retVal;

Answer 1

The part is declaring a generic type argument T. If you were to omit this part, the compiler would likely complain that the type T doesn't exist.

In this case, T serves as a placeholder for an actual type, which will only be determined when the method is actually called with non-generic type arguments.

public  T readObjectData(...
        ^  ^
        |  + Return type
        + Generic type argument