反射の簡単な使用

        //        
        Class > cls =Class.forName("test.reflect.OperationAdd"); //   Class  
        Constructor> cons [] = cls.getConstructors() ; //       
        for(int x = 0; x < cons.length; x++) {
            System.out.println(cons[x]);
        }

       //         
            Constructor> con=cls.getConstructor(double.class,double.class);
            Object ob=con.newInstance(1,2);
            System.out.println(ob);
            //      
            con=cls.getConstructor();
            ob=con.newInstance();
        System.out.println(ob);


        //      
        Method setMet = cls.getMethod("method");
        Method method2=cls.getMethod("method2",String.class,int.class);


        setMet.invoke(ob);
        method2.invoke(ob,"lance",666);




        //       
        Field field [] = cls.getDeclaredFields() ;
        for(int x = 0; x < field.length; x++) {
            System.out.println(field[x]);
        }


        Field nameField = cls.getDeclaredField("name") ; //   name  
        nameField.setAccessible(true) ; //      ,     public
        nameField.set(ob, "  ") ; // Person  .name = "  "
        System.out.println(nameField.get(ob)); // Person  .name

public class OperationAdd implements Operation {
    private String name;
    private int num;
    @Override
    public double getResult(double a, double b) {
        return a+b;
    }

    public OperationAdd(){
        System.out.println("        ");
    }
    public OperationAdd(double a,double b){
        System.out.println("a:"+a+",b"+b);
    }

    public void method(){
        System.out.println("      ");
    }

    public void method2(String a,int b){
        System.out.println(a+" "+b);
    }
}