Java Reflection Learning Notes

Sample class

@SuppressWarnings ("Unused") Public classPerson { PublicString Name; Private intAge ;  PublicGender Gender; Private StaticString species = "human";  PublicPerson () {Name= "Anonymous"; Age=-1; }     PublicPerson (String name) {Name=name; }    PrivatePerson (String name,intAge ) {Name=name; Age=Age ; }        PrivatePerson (Gender g) {Gender=G; }     Public voidRun () {System.out.println (Name+ "Run!"); }     Public voidAttack () {System.out.println (Name+ "Hit!"); }     Public voidAttack (String name) {System.out.println (name+ "hit" +name+ "!"); }    Private voidEat (String food) {System.out.println (Name+ "Eat" +Food ); }     Public voidintroduce () {System.out.println ("My name is" +name+ ", I Am" +age+ "year old. "); }     Public Static voidPlayGame (String gamename) {System.out.println ("Play" +gamename+ "game"); }     Public Static voidMain (string[] args) {System.out.println ("Main");  for(String S:args) System.out.println (s); }}enumgender{Male,female}

Non-parametric constructors for reflection classes:

@Test // non-parametric constructors for reflection classes  Public void throws exception{    = Class.forName ("Pro.shaowei.reflect.Person");    Constructor c=clazz.getconstructor ();     = (person) c.newinstance ();     = (person) clazz.newinstance ();    P.introduce ();    P.run ();    P1. Introduce ();    P1. Run ();}

A parameter constructor for a reflection class:

@Test // parametric constructors for reflection classes  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Constructor c=clazz.getconstructor (String.  Class);    Person P= ((person) c.newinstance ("Zhang San"));    P.introduce ();    P.run ();}

Private constructors for reflection classes:

@Test//private constructors for reflection classes Public voidConstructor3 ()throwsexception{Class clazz=class.forname ("Pro.shaowei.reflect.Person"); //when you reflect a private constructor, you must use the Getdeclaredconstructor methodConstructor C=clazz.getdeclaredconstructor (String.class,int.class); C.setaccessible (true);//violent reflexesPerson p= (person) c.newinstance ("Zhang San", 25));    P.introduce (); P.run ();}

Public non-parametric methods for reflection classes:

@Test // Public non-parametric method of reflection class  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Method=clazz.getmethod ("Run");    Method.invoke (P);}

The public-aware method of the Reflection class:

@Test // Public-owned methods for reflection classes  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Method=clazz.getmethod ("Attack", String.  Class);    Method.invoke (P,"John Doe");}

Private, parameter-aware methods for reflection classes:

@Test // private and parametric methods for reflection classes  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Method=clazz.getdeclaredmethod ("Eat", String.  Class);    Method.setaccessible (true);    Method.invoke (P,"banana");}

Static and parametric methods for reflection classes:

@Test // static and Parametric methods for reflection classes  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Method=clazz.getdeclaredmethod ("PlayGame", String.  Class);    Method.setaccessible (true);    Method.invoke (P,"minesweeper");}

The main method of the Reflection class:

@Test // The main method of the Reflection class  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Method=clazz.getdeclaredmethod ("main", string[].  Class);    Method.setaccessible (true);    Method.invoke (P, (Object)new string[]{"1", "2"});

Reflection Class-Public fields:

@Test // Reflection Class-Public fields  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Field field=clazz.getfield ("Name");    System.out.println (Field.get (P));    " Harry ");    P.introduce ();}

Reflection Class-Private fields:

@Test // Reflection Class-Private fields  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Field field=clazz.getdeclaredfield ("Age");    Field.setaccessible (true);    System.out.println (Field.get (P));     7);    P.introduce ();}

Reflection class private static fields:

@Test // Reflection class private static field  Public void throws exception{    Class clazz=class.forname ("Pro.shaowei.reflect.Person");    Person P=(person) clazz.newinstance ();    Field field=clazz.getdeclaredfield ("species");    Field.setaccessible (true);    System.out.println (Field.get (P));    " Undead ");    System.out.println (Field.get (P));}

Java Reflection Learning Notes