Java Learning--reflection constructor operations

1 @Test2      Public voidtest1 () throws exception{3String ClassName ="Com.atguigu.java.Person";4Class Clazz =Class.forName (className);5         //creates an object for the corresponding run-time class. Using Newinstance () is actually the constructor that invokes the null parameter of the runtime class. 6         //To be able to create a success: ① requires the corresponding runtime class to have a constructor with null parameters. The permissions of the ② constructor are sufficient. 7Object obj =clazz.newinstance ();8Person p =(person) obj;9System. out. println (p);Ten}

1 @Test2      Public voidtest2 () throws classnotfoundexception{3String ClassName ="Com.atguigu.java.Person";4Class Clazz =Class.forName (className);5         6Constructor[] Cons =clazz.getdeclaredconstructors ();7          for(Constructor c:cons) {8System. out. println (c);9         }Ten}

1 //invokes the specified constructor to create an object of the run-time class2 @Test3      Public voidTest3 () throws exception{4String ClassName ="Com.atguigu.java.Person";5Class Clazz =Class.forName (className);6         7Constructor cons = Clazz.getdeclaredconstructor (String.class,int.class);8Cons.setaccessible (true);9Person P = (person) cons.newinstance ("Luo Wei", -);TenSystem. out. println (p); One}

1  classPerson extends creature<string>implements comparable,myinterface{2      PublicString name;3     Private intAge ;4     intID;5     //When you create a class, try to keep an empty parameter constructor. 6      PublicPerson () {7 super ();8 //System.out.println ("The weather is very sultry today");9     }Ten      PublicPerson (String name) { One super (); A          This. Name =name; -     } -     PrivatePerson (String name,intAge ) { the super (); -          This. Name =name; -          This. Age =Age ; -     } +      PublicString GetName () { -         returnname; +     } A      Public voidsetName (String name) { at          This. Name =name; -     } -      Public intGetage () { -         returnAge ; -     } -      Public voidSetage (intAge ) { in          This. Age =Age ; -     } to      +      Public intgetId () { -         returnID; the     } *      Public voidSetId (intID) { $          This. ID =ID;Panax Notoginseng     } -@MyAnnotation (value ="abc123") the      Public voidShow () { +System. out. println ("I am a person! "); A     } the      +     PrivateInteger Display (String Nation,integer i) throws exception{ -System. out. println ("My nationality is:"+nation); $         returni; $     } - @Override -      PublicString toString () { the         return "Person [Name="+ name +", age="+ Age +"]"; -     }Wuyi @Override the      Public intcompareTo (Object o) { -         //TODO auto-generated Method Stub Wu         return 0; -     } About      $      Public Static voidinfo () { -System. out. println ("The Chinese! "); -     } -      A     classbird{ +          the     } -      $}

1ImportStaticJava.lang.annotation.ElementType.CONSTRUCTOR;2ImportStaticJava.lang.annotation.ElementType.FIELD;3ImportStaticJava.lang.annotation.ElementType.LOCAL_VARIABLE;4ImportStaticJava.lang.annotation.ElementType.METHOD;5ImportStaticJava.lang.annotation.ElementType.PARAMETER;6ImportStaticJava.lang.annotation.ElementType.TYPE;7 8 import java.lang.annotation.Retention;9 import Java.lang.annotation.RetentionPolicy;Ten import Java.lang.annotation.Target; One  A @Target ({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, local_variable}) - @Retention (retentionpolicy.runtime) -  Public@interface myannotation { the String value (); -}

 1  public  class  Creature<t>{ public  double   weight;  3   Public  void   breath () { 5  System. out . println ( "  breathe!   );  6   7  }

1 import java.io.Serializable; 2 3 public interface MyInterface extends serializable{ 4 5 }

Java Learning--reflection constructor operations