java反射的四个加载器

加载器是个好东西

public static void main(String[] args) throws SecurityException, NoSuchMethodException, IllegalArgumentException, InstantiationException, IllegalAccessException, InvocationTargetException {
        // 反射String类的所有构造方法
        Class clz = Student.class;

        System.out.println("所有构造方法");
        // Constructor[] cons = clz.getConstructors();
        Constructor[] cons = clz.getDeclaredConstructors();
        for (Constructor con : cons) {
            // System.out.println("访问修饰权限：" +
            // Modifier.toString(con.getModifiers()));
            // System.out.println("方法名：" + con.getName());
            // System.out.println("****************************");
            System.out.println(Modifier.toString(con.getModifiers()) + " "
                    + con.getName());
        }

        
        //找无参的构造方法    Student s = new Student();
        Constructor con = clz.getDeclaredConstructor();
        Object obj = con.newInstance();
        System.out.println(obj);
        
        //找带string,int类型参数的构造方法 Student s = new Student("zhangsan",12)
        con = clz.getDeclaredConstructor(String.class, int.class);
        obj = con.newInstance("zhangsan", 12);
        System.out.println(obj);
        
        con = clz.getDeclaredConstructor(String.class);
        
        }