A Java generic class will miss generic info on all fields if this class is used in non-generic way?

Question

There is a generic class:

class Test<T> {
    T genericTypeField;
    List<String> list;
}

void method1(Test test) {
    for (String value : test.list) { // Compiler error

    }

    // Correct
    for (Object value : test.list) {

    }
}

void method2(Test<?> test) {
    // Correct
    for (String value : test.list) {

    }
}

It seems that if use a generic class in non-generic way, all generic fields in this class will lose the generic info.

Does the Java specification has any description about this?

Answer 1

Type of test in method1(Test test) is a raw type.

This is the normal behaviour of Raw types in Java. It's well declared here and there. The important note for your case is:

The type of a constructor (§8.8), instance method (§8.4, §9.4), or non-static field (§8.3) M of a raw type C that is not inherited from its superclasses or superinterfaces is the raw type that corresponds to the erasure of its type in the generic declaration corresponding to C.

Answer 2

If you not provide generic type it always take as object

if you want to use string use like

   void method1(Test<String> test) {
     for (String value : test.list) { // This Compiler 
     }
   }