内省（Inrospector）学习总结

一、Introspector介绍

内省主要为了剖析JavaBean；

JavaBean：

(1)一个public的类；

(2)主要用于存储数据；

(3)getter & setter方法；

需要涉及Inrospector,BeanInfo,PropertyDescriptor等类；

二、Introspector开发

package org.xiazdong.introspector;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;

import org.junit.Test;
import org.xiazdong.Person;

public class IntrospectorDemo01 {
	//获得person类的所有bean属性
	@Test
	public void test1() throws Exception{
		BeanInfo info = Introspector.getBeanInfo(Person.class);
		PropertyDescriptor[] pds = info.getPropertyDescriptors();
		for(PropertyDescriptor pd:pds){
			System.out.println(pd.getPropertyType()+" "+pd.getName());
		}
	}
	//获得Person（不包含Object类）的所有bean属性
	@Test
	public void test2() throws Exception{
		BeanInfo info = Introspector.getBeanInfo(Person.class,Object.class);
		PropertyDescriptor[] pds = info.getPropertyDescriptors();
		for(PropertyDescriptor pd:pds){
			System.out.println(pd.getPropertyType()+" "+pd.getName());
		}
	}
	//设置Person的age属性
	@Test
	public void test3() throws Exception{
		Person p = new Person();
		PropertyDescriptor pd = new PropertyDescriptor("age", Person.class);
		Method method = pd.getWriteMethod();
		method.invoke(p, 20);
		System.out.println(p.getAge());
	}
	//调用Person的getAge()
	@Test
	public void test4() throws Exception{
		Person p = new Person("xiazdong",30);
		PropertyDescriptor pd = new PropertyDescriptor("age", Person.class);
		Method method = pd.getReadMethod();
		System.out.println(method.invoke(p, null));
	}
}