Is an Enum Constant-Specific Class Body Static or Non-Static?

Are enum constant-specific class bodies in Java static or non-static?

public enum MyEnum {
    CONSTANT_ONE {
        // Specific class body for CONSTANT_ONE
    },

    CONSTANT_TWO {
        // Specific class body for CONSTANT_TWO
    };
}

In Java, enum constant-specific class bodies define behavior for each constant, and they can be thought of either as static or non-static depending on context.

public enum Action {
    START {
        @Override
        public void perform() {
            System.out.println("Starting...");
        }
    },

    STOP {
        @Override
        public void perform() {
            System.out.println("Stopping...");
        }
    };

    public abstract void perform();
}

Causes

• Enum constants in Java are singleton instances.

Solutions

• The class bodies of enum constants are treated as anonymous inner classes, leading to instance members being non-static.

Mistake: Assuming that enum constant-specific bodies can directly access static variables of the enum.

Solution: Use instance variables or methods for accessing non-static members.

Mistake: Not overriding abstract methods properly in enum constant-specific classes.

Solution: Ensure that each constant properly implements the required abstract methods.