Avoid duplicate addition of void.class in ClassUtils static initialization

[cherishsince]

static {
		primitiveWrapperTypeMap.put(Boolean.class, boolean.class);
		primitiveWrapperTypeMap.put(Byte.class, byte.class);
		// ...
               // Add 'void.class' repeatedly
		primitiveTypes.add(void.class);
		// ...
	}

[bclozel]

I don’t understand the goal of this issue.
Is there a bug somewhere, in this case do you have a sample showing the problem?
Is this an improvement proposal - in this case could you send a PR to the project or give more context about the improvement?

Thanks

[cherishsince]

	static {
		primitiveWrapperTypeMap.put(Boolean.class, boolean.class);
		primitiveWrapperTypeMap.put(Byte.class, byte.class);
		primitiveWrapperTypeMap.put(Character.class, char.class);
		primitiveWrapperTypeMap.put(Double.class, double.class);
		primitiveWrapperTypeMap.put(Float.class, float.class);
		primitiveWrapperTypeMap.put(Integer.class, int.class);
		primitiveWrapperTypeMap.put(Long.class, long.class);
		primitiveWrapperTypeMap.put(Short.class, short.class);
		primitiveWrapperTypeMap.put(Void.class, void.class);

		// Map entry iteration is less expensive to initialize than forEach with lambdas
		for (Map.Entry<Class<?>, Class<?>> entry : primitiveWrapperTypeMap.entrySet()) {
			primitiveTypeToWrapperMap.put(entry.getValue(), entry.getKey());
			registerCommonClasses(entry.getKey());
		}

		Set<Class<?>> primitiveTypes = new HashSet<>(32);
		primitiveTypes.addAll(primitiveWrapperTypeMap.values());
		Collections.addAll(primitiveTypes, boolean[].class, byte[].class, char[].class,
				double[].class, float[].class, int[].class, long[].class, short[].class);
		primitiveTypes.add(void.class);
		for (Class<?> primitiveType : primitiveTypes) {
			primitiveTypeNameMap.put(primitiveType.getName(), primitiveType);
		}

		registerCommonClasses(Boolean[].class, Byte[].class, Character[].class, Double[].class,
				Float[].class, Integer[].class, Long[].class, Short[].class);
		registerCommonClasses(Number.class, Number[].class, String.class, String[].class,
				Class.class, Class[].class, Object.class, Object[].class);
		registerCommonClasses(Throwable.class, Exception.class, RuntimeException.class,
				Error.class, StackTraceElement.class, StackTraceElement[].class);
		registerCommonClasses(Enum.class, Iterable.class, Iterator.class, Enumeration.class,
				Collection.class, List.class, Set.class, Map.class, Map.Entry.class, Optional.class);

		Class<?>[] javaLanguageInterfaceArray = {Serializable.class, Externalizable.class,
				Closeable.class, AutoCloseable.class, Cloneable.class, Comparable.class};
		registerCommonClasses(javaLanguageInterfaceArray);
		javaLanguageInterfaces = new HashSet<>(Arrays.asList(javaLanguageInterfaceArray));
	}

Optimization suggestions

'primitiveWrapperTypeMap' has been added void.class So primitiveTypes.add(void.class) is a redundant operation.

[sbrannen]

Thanks for pointing this out.

I'll tidy it up.