反射-copy方法模拟

package com.unit;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class ReflectTester {
	/**   
	     * 在这个类里面存在有copy()方法，根据指定的方法的参数去 构造一个新的对象的拷贝   
	     * 并将他返回   
	 * @throws NoSuchMethodException 
	 * @throws InvocationTargetException 
	 * @throws IllegalAccessException 
	 * @throws InstantiationException 
	 * @throws SecurityException 
	 * @throws IllegalArgumentException */
		@SuppressWarnings({ "rawtypes", "unchecked" })
		public Object copy(Object obj) throws IllegalArgumentException, SecurityException, InstantiationException, 
			IllegalAccessException, InvocationTargetException, NoSuchMethodException{
			//获得对象的类型 
			Class classType=obj.getClass();
			System.out.println("该对象的类型是："+classType.toString());
			//通过默认构造方法去创建一个新的对象，getConstructor的视其参数决定调用哪个构造方法
			Object objectCopy=classType.getConstructor(new Class[]{}).newInstance(new Object[]{});
			//获得对象的所有属性 
			//[private java.lang.Long com.unit.Customer.id, private java.lang.String com.unit.Customer.name, private int com.unit.Customer.age]
			Field[] fields=classType.getDeclaredFields();
			for(int i=0 ; i < fields.length ; i++){
				Field field = fields[i];
				String fieldName = field.getName();
				String stringLetter = fieldName.substring(0,1).toUpperCase();
				//获得相应属性的getXXX和setXXX方法名称
				String getName = "get"+stringLetter+fieldName.substring(1);
				String setName = "set"+stringLetter+fieldName.substring(1);
				//获取相应的方法
				Method getMethod = classType.getMethod(getName,new Class[]{});
				Method setMethod = classType.getMethod(setName, new Class[]{field.getType()});
				//调用源对象的getXXX()方法 
				Object value = getMethod.invoke(obj, new Object[]{});
				System.out.println(fieldName+" :"+value); 
				//调用拷贝对象的setXXX()方法
				setMethod.invoke(objectCopy, new Object[]{value});
			}
			return objectCopy;
		}
		public static void main(String[] args) throws IllegalArgumentException, SecurityException, 
				InstantiationException, IllegalAccessException, InvocationTargetException, NoSuchMethodException {
			Customer customer=new Customer();
			customer.setName("yc");
			customer.setId(new Long(1234));
			customer.setAge(19);
			Customer customer2=null;
			customer2=(Customer)new ReflectTester().copy(customer);
			System.out.println(customer.getName()+" "+customer2.getAge()+" "+customer2.getId());
			System.out.println(customer);
			System.out.println(customer2);
		}
		
}
class Customer{
	private Long	id;
	private String name;
	private int age;
	
	public Customer(){
		
	}
	public Long getId() {
		return id;
	}
	public void setId(Long 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;
	}
}