Java Reflection 概述

public class TestReflection {
	public static void main(String[] args) throws Exception {
		// 通过"类名.class"创建 Class 类（运行时类）的对象
		Class<Person> clazz = Person.class;
		// 1.创建 clazz 对应的运行时类 Person 的对象并赋给 Person 类对象的引用 p
		Person p = clazz.newInstance();
		// 2.通过反射，调用运行时类的属性
		Field f1 = clazz.getField("age");// 调 public 修饰的属性并赋给 Field 类对象的引用 f1
		f1.set(p, 16);
		Field f2 = clazz.getDeclaredField("name");// 调非 public 修饰的属性并赋给 Field
													// 类对象的引用 f2
		f2.setAccessible(true);
		f2.set(p, "chen");
		System.out.println(p);// Person [age=16, name=chen]
		// 3.通过反射，调用运行时类的
		Method m1 = clazz.getMethod("custom");
		m1.invoke(p);// custom method
		Method m2 = clazz.getMethod("custom", String.class);
		m2.invoke(p, "arg");// custom method arg
		// 说明唯一性
		System.out.println(clazz == new Person().getClass());// true
	}
}
class Person {
	public int age;
	private String name;
	public Person() {
		super();
	}
	public Person(int age, String name) {
		super();
		this.age = age;
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public String toString() {
		return "Person [age=" + age + ", name=" + name + "]";
	}
	public void custom() {
		System.out.println("custom method");
	}
	public void custom(String s) {
		System.out.println("custom method " + s);
	}
}