Class,Method

• public final class Class<T>
  extends Object
  implements Serializable, GenericDeclaration, Type, AnnotatedElement

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

  Class has no public constructor构造方法. Instead加载Class objects are constructed automatically自动by the Java Virtual Machine as classes are loaded and by calls to thedefineClass method in the class loader加载.

  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指定type (or for void) using a class literal类字面值. See Section 15.8.2 ofThe Java™ Language Specification. For example:

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

  Since:
  JDK1.0
  See Also:
  
  
  ClassLoader.defineClass(byte[], int, int), Serialized Form
  
  
  
  
  
  

  • public final class Method
    extends AccessibleObject
    implements GenericDeclaration, Member

    A Method provides information about, and access to, a single method on a class or interface. The reflected反映 method may be a class method or an instance method (including an abstract method).

    A Method permits允许widening扩展conversions to occur when matching the actual parameters实参 to invoke调用 with the underlying method's formal parameters, but it throws anIllegalArgumentException if a narrowing缩小 conversion would occur.

    See Also:
    Member, Class, Class.getMethods(), Class.getMethod(String, Class[]), Class.getDeclaredMethods(),Class.getDeclaredMethod(String, Class[])