Reflection operations classes, methods, properties, etc.

1. Operation class

Gets the class and gets an instance object through reflection

Class Class1 = Student.class;

Student Student = (Student) class1.newinstance (); Default call no parameter construction method

Student.setname ("heh");

System.out.println (Student.getname ());

2. Operation Construction Method

gets the constructor method for the specified parameter type that creates an instance object of a specific parameter value from this object

Class Class1 = Student.class;

constructor<?> Constructor = Class1.getconstructor (String.class,string.class,int.class);

Student student1= (Student) constructor.newinstance ("123", "456", 12);

System.out.println (Student1.getage ());

3. General method of operation

Class Class1 = Student.class;

Student student= (Student) class1.newinstance ();

Method Method=class1.getmethod ("Setage", Int.class);

Method.invoke (student,10);

System.out.println (Student.getage ());

4. Operation Properties

Class Class1 = Student.class;

Student Student = (Student) class1.newinstance ();

Field Fiel=class1.getdeclaredfield ("Age");

Fiel.setaccessible (TRUE); The member variable in the Accessibletest class is private, so you must do this

Fiel.set (student, 10);

System.out.println (Student.getage ());

5. Modifying the value of an array

Int[] a= {1,2,3,4,5,6,7,8,9};

Class Class1 = A.getclass (). Getcomponenttype (); Returns the Class that represents the array component type. If this class does not represent an array class, this method returns null

System.out.println ("Name of the array data:" +class1.getname ());

System.out.println ("Length of the array:" +array.getlength (a));

System.out.println ("The value of the first element of the data:" +array.get (a,0));

Array.set (A, 0, 12);

System.out.println ("The value of the first element of the data:" +array.get (a,0));

This article is from the "Programmer rookie" blog, be sure to keep this source http://5345468.blog.51cto.com/5335468/1690318

Reflection operations classes, methods, properties, etc.