java中的反射机制（The reflection mechanism in Java）.docVIP

java中的反射机制（The reflection mechanism in Java） The reflection mechanism in Java Keyword: java reflection mechanism reflection 1) concept: Is in the running state, for any one class, are able to know all the properties and methods of the class; for an arbitrary object can call it any one method; this method of dynamic information and dynamic call object function called reflection mechanism for the Java language. 2) function: At run time, determine the class to which any object belongs; The object that constructs any class at run time; At run time, determine the member variables and methods that any class has; The method of calling any object at run time; Dynamic agent generation. 3) obtain the specific attributes of an object: Class ownerClass = owner.getClass (): get the object owners Class. Field field = ownerClass.getField (fieldName): properties of class declarations are obtained through Class. Object property = field.get (owner): an instance of this property is obtained through an object, and if this property is non-public, it is reported to IllegalAccessException. If you need access to the private property of the object, you need to call first: AccesibleObject.setAccessible (Field name, true); If the static property of the Class is obtained, the third sentence is replaced with the Object property=field.get (Class name) instead of the name of the instance. 4) the method of executing an object: Public, Object, invokeMethod (Object, owner, String, methodName, Object[], args) throws Exception { Class ownerClass = owner.getClass (); Class[] argsClass = new Class[args.length]; For (int, I = 0, j = args.length, I J, i++) { ArgsClass = args.getClass (); } Method method = ownerClass.getMethod (methodName, argsClass); Return method.invoke (owner, args); } If it is the static method for executing a class: method.invoke (null, args); 5) create an instance of an object: Public, Object, newInstance (String, className, Object[], args), throws, Exception { Class newoneClass = C