一段值得回味的代码 博客分类： 开源jar包学习 经典

这个代码应该是每一个开源框架的ClassUtils都有的吧！本人觉得这段代码和经典，但又说不出哪里好，只可意会，不可言谈。

 

public class ClassUtils{

/**
	 * Map with primitive wrapper type as key and corresponding primitive
	 * type as value, for example: Integer.class -> int.class.
	 */
	private static final Map primitiveWrapperTypeMap = new HashMap(8);

	/**
	 * Map with primitive type name as key and corresponding primitive
	 * type as value, for example: "int" -> "int.class".
	 */
	private static final Map primitiveTypeNameMap = new HashMap(16);


	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);

		Set primitiveTypeNames = new HashSet(16);
		primitiveTypeNames.addAll(primitiveWrapperTypeMap.values());
		primitiveTypeNames.addAll(Arrays.asList(new Class[] {
				boolean[].class, byte[].class, char[].class, double[].class,
				float[].class, int[].class, long[].class, short[].class}));
		for (Iterator it = primitiveTypeNames.iterator(); it.hasNext();) {
			Class primitiveClass = (Class) it.next();
			primitiveTypeNameMap.put(primitiveClass.getName(), primitiveClass);
		}
	}

}