Maximum number of enum elements in Java

Question

What is the maximum number of elements allowed in an enum in Java?

I wanted to find out the maximum number of cases in a switch statement. Since the largest primitive type allowed in switch is int, we have cases from -2,147,483,648 to 2,147,483,647 and one default case. However enums are also allowed... so the question..

Answer 1

From the class file format spec:

The per-class or per-interface constant pool is limited to 65535 entries by the 16-bit constant_pool_count field of the ClassFile structure (§4.1). This acts as an internal limit on the total complexity of a single class or interface.

I believe that this implies that you cannot have more then 65535 named "things" in a single class, which would also limit the number of enum constants.

If a see a switch with 2 billion cases, I'll probably kill anyone that has touched that code.

Fortunately, that cannot happen:

The amount of code per non-native, non-abstract method is limited to 65536 bytes by the sizes of the indices in the exception_table of the Code attribute (§4.7.3), in the LineNumberTable attribute (§4.7.8), and in the LocalVariableTable attribute (§4.7.9).