java反射

之前写过一篇Java反射的博客，发现有的地方错了，所以删了那篇，重新写mark一下，以便以后复习，东西很久没用就容易忘记。
1.主要类：Class,Constructor,Method,Field。现在的pojo类一般会把属性声明成private所以Field也不怎么用，一般通过截取Method来获取属性
2.每个类、类的实例都可以理解成Class的实例，甚至Class可以看成它自己本身的实例***
3.Class类中以getDeclared开头的，一般只能获取自己声明的
    Class.getFields(...)//获取public修饰的属性(包括父类声明的public属性)
    Class.getDeclaredFields(...)//获取自己声明的属性(包括private修饰的)
    Class.getMethods(...)//获取public修饰的方法(包括父类声明的public方法)
    Class.getDeclaredMethods(...)//获取自己声明的方法(包括private修饰的)
4.eg:通过反射复制对象，

public class TestClass {
	public static void main(String[] args) throws Exception
	{
		Person p = new Person(1, "root", 12, "430981", "[e-mail]", "12312312312");
		System.out.println(p);
		Person pCopy = (Person) new TestClass().copy(p);
		System.out.println(pCopy);
	}
	//复制方法，拷贝属性
	public Object copy(Object obj) throws Exception
	{
		//1.获取obj类型
		Class<?> classType = obj.getClass();
		//2.调用无参构造器
		Object objCopy = classType.getConstructor(null).newInstance(null);
		/*
		 * 3.给所有属性赋值，pojo类属性一般为private的，
		 * classType.getDeclaredFields();只能获取自己声明的属性(包含private修饰的)
		 * classType.getFields();只能获取public修饰的属性(包含父类的)
		 * 所有一般通过截取method来获取属性
		 */
		Method[] methods = classType.getMethods();
		for (Method method : methods)
		{
			String mname = method.getName();//方法名
			Class<?> returnType = method.getReturnType();//方法返回类型
			String fname =null;
			if (mname.startsWith("get") //get开头的方法
					&& !mname.equals("getClass")//排除getclass方法
					&& !returnType.equals(Void.TYPE))//排除返回值为空的方法
			{
				fname = mname.substring(3);
			} else if (mname.startsWith("is") //
					&& (returnType.equals(Boolean.TYPE)//boolean
                    || returnType.equals(Boolean.class)))// Boolean
			{
				fname = mname.substring(2);
			}
			if(null != fname)
			{
				//调用get方法获取属性值
				Object value = method.invoke(obj, null);
				//利用set方法给属性赋值
				Method setMethod = classType.getMethod("set"+fname, returnType);
				setMethod.invoke(objCopy, value);
			}
		}
		return objCopy;
	}
}

返回结果：
{id=1;name=root;age=12;sex=女;identity=123;email=[e-mail];phone=021-1234567;address=[中国-上海省-上海市-紫薇路1弄1号]}
{id=1;name=root;age=12;sex=女;identity=123;email=[e-mail];phone=021-1234567;address=[中国-上海省-上海市-紫薇路1弄1号]}

其中person类如下：Animal是一个基类，person继承Animal，并带有Address属性。

public class Animal {
	private int id;//唯一编号
	private String name;//名称
	private boolean sex;//性别
	private int age;//年纪
	public Animal() {
	}
	public Animal(int id, String name, int age) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
	}
	public boolean isSex()
	{
		return sex;
	}
	public void setSex(boolean sex)
	{
		this.sex = sex;
	}
	public int getId()
	{
		return id;
	}
	public void setId(int id)
	{
		this.id = id;
	}
	public String getName()
	{
		return name;
	}
	public void setName(String name)
	{
		this.name = name;
	}
	public int getAge()
	{
		return age;
	}
	public void setAge(int age)
	{
		this.age = age;
	}
	
	@Override
	public String toString()
	{
		return "[id="+id+";name="+name+";age="+age+";sex=(sex==true?"男":"女")+"]";
	}
}

public class Person extends Animal{

	private String identity;
	private String email;
	private String phone;
	private Address address;
	public Person() {
	}
	
	public Person(int id,String name,int age,String identity, String email, String phone) {
		super(id,name,age);
		this.identity = identity;
		this.email = email;
		this.phone = phone;
		this.address = new Address("1弄1号");
	}

	public String getIdentity()
	{
		return identity;
	}
	
	public void setIdentity(String identity)
	{
		this.identity = identity;
	}
	
	public String getEmail()
	{
		return email;
	}

	public void setEmail(String email)
	{
		this.email = email;
	}

	public String getPhone()
	{
		return phone;
	}

	public void setPhone(String phone)
	{
		this.phone = phone;
	}

	public Address getAddress()
	{
		return address;
	}

	public void setAddress(Address address)
	{
		this.address = address;
	}
	
	@Override
	public String toString()
	{
		return "{id="+getId()+";name="+getName()+";age="+getAge()
				+";sex="+(isSex()==true?"男":"女")
				+";identity="+identity+";email="+email+";phone="+phone
				+";address="+address+"}";
	}
}

class Address{
	private String country;//国家
	private String province;//省份
	private String city;//城市
	private String street;//街道
	private String local;//详细地方
	public Address() {
	}
	public Address(String local) {
		this.country = "中国";
		this.province = "上海";
		this.city = "上海";
		this.street = "紫薇路";
		this.local = local;
	}

	public String getCountry()
	{
		return country;
	}
	public void setCountry(String country)
	{
		this.country = country;
	}
	public String getProvince()
	{
		return province;
	}
	public void setProvince(String province)
	{
		this.province = province;
	}
	public String getCity()
	{
		return city;
	}
	public void setCity(String city)
	{
		this.city = city;
	}
	public String getStreet()
	{
		return street;
	}
	public void setStreet(String street)
	{
		this.street = street;
	}
	public String getLocal()
	{
		return local;
	}
	public void setLocal(String local)
	{
		this.local = local;
	}
	@Override
	public String toString()
	{
		return "["+country+"-"+province+"省-"+city+"市-"+street+local+"]";
	}
	
}