基于Javaclass对象说明、Java静态变量声明和赋值说明(详解)-创新互联

先看下JDK中的说明：

java.lang.Object
  java.lang.Class
  
Instances of the class Class represent classes and interfaces in a running Java application. An enum is a kind of class and an annotation is a kind of interface. Every array also belongs to a class that is reflected as a Class object that is shared by all arrays with the same element type and number of dimensions. The primitive Java types (boolean, byte, char, short, int, long, float, and double), and the keyword void are also represented as Class objects.

Class has no public constructor. Instead Class objects are constructed automatically by the Java Virtual Machine as classes are loaded and by calls to the defineClass method in the class loader.

The following example uses a Class object to print the class name of an object:

   void printClassName(Object obj) {
     System.out.println("The class of " + obj +
              " is " + obj.getClass().getName());
   }
 
It is also possible to get the Class object for a named type (or for void) using a class literal.

  System.out.println("The name of class Foo is: "+Foo.class.getName());

在一个运行着的JAVA应用中，类的任何实例都可以用Class对象来指代，Class可以指代所有的类和接口。枚举属于类，注解属于接口，均可以用Class指代。每个数组均属于反射的Class对象，数组中的每个元素和维度也同样拥有Class对象。Java基本类型（boolean, byte, char, short, int, long, float, and double）以及关键字void也都可以用Class指代。

Class类不存在构造函数，当类被加载过程中由JVM通过调用类加载器中的defineClass方法自动构造。

下面的例子是将一个对象通过Class对象打印出类名。
   void printClassName(Object obj) {
     System.out.println("The class of " + obj +
              " is " + obj.getClass().getName());
   }
通过class关键字指定类型也是可以得到Class对象的
  System.out.println("The name of class Foo is: "+Foo.class.getName());