java 反射List_JAVA_编程开发_程序员俱乐部

class="java" name="code">
package com.enhance.reflect;

import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.lang.ArrayUtils;

public class ReflectTest {
	public static void main(String[] args) throws Exception{
        //反射List 集合
		reflectCollection();
       } 



/**
	 * 反射获取集合属性 和 集合中的 泛型 
	 * @throws Exception 
	 */
	public static void reflectCollection() throws Exception{
		List<Integer> nums=new ArrayList<Integer>();
		nums.add(1);
		
		Person p =new Person();
		p.setAge(18);
		p.setName("luck");
		
		List<Person> list=new LinkedList<Person>();
		list.add(p);
		
		List<Address> address = new ArrayList<Address>();
		Address addr=new Address();
		addr.setAddName("上海人民广场");
		addr.setAddNo("add001");
		address.add(addr);
		
		p.setAddress(address);
		
		TestA a=new TestA();
		a.setNums(nums);
		a.setP(p);
		a.setAge(16);
		a.setBig(55);
		a.setData(list);
		
		TestB b=new TestB();
		copyProperties(a,b);
		//BeanUtils.copyProperties(b,a); //只能copy 类型相同的,
		System.out.println("基本类型:"+b.getBig());
		System.out.println("包装类型:"+b.getAge());
		System.out.println("自定义类"+b.getP().getAge());
		System.out.println("List<包装类型>:"+b.getNums().get(0));
		System.out.println("List<自定义类>:"+b.getData().get(0).getAge());
		System.out.println("List<自定义类.List>:"+b.getData().get(0).getAddress().get(0).getAddName());
		
	}

/**
	 * 能 复制 相同类型的属性
	 * 也能复制 "属性名相同,类型不同" 的属性
	 * @param src 原对象
	 * @param dest 目标对象
	 * @throws Exception
	 * Person ==> People
	 * 注意:本程序省略 NoSuchMethodException 的判断
	 *    每获取 Method 都需要判断  NoSuchMethodException 后在 invoke 
	 */
	public static void copyProperties(Object src,Object dest) throws Exception{
		Class sclazz =src.getClass();
		Class dclazz =dest.getClass();
		//Object.class 为 stopClass  不反射的 Class
		PropertyDescriptor[] ps=Introspector.getBeanInfo(dclazz,Object.class).getPropertyDescriptors();
		for (PropertyDescriptor prop : ps) {
			System.out.println(prop.getPropertyType());
			if(prop.getPropertyType() == Class.class){ //Class 不反射
				continue;
			}else if(prop.getPropertyType().isPrimitive()){ //基本数据类型
				prop.getWriteMethod().invoke(dest, sclazz.getMethod(prop.getReadMethod().getName()).invoke(src));
			}else if(isWarpType(prop.getPropertyType().getName())){ //包装类型
				prop.getWriteMethod().invoke(dest, sclazz.getMethod(prop.getReadMethod().getName()).invoke(src));
			}else if(prop.getPropertyType() == List.class){ //List 集合类型
				Object obj=sclazz.getMethod(prop.getReadMethod().getName()).invoke(src);
				System.out.println("class:"+obj.getClass());
				if(obj !=null){
					List srcList=(List)obj;
					Class listClazz=obj.getClass();
					ParameterizedType pt= (ParameterizedType)prop.getReadMethod().getGenericReturnType();
					Class type = (Class)pt.getActualTypeArguments()[0]; 
					Object destList=listClazz.newInstance();
					Method addMethod=listClazz.getMethod("add",Object.class);
					Integer i=new Integer(1);
					for (Object object : srcList) {
						Object item=null;
						if(isWarpType(type.getName())){
							item=type.getConstructor((Class)object.getClass().getField("TYPE").get(object)).newInstance(object);
						}else{
							item=type.newInstance();
							copyProperties(object,item);
						}
						addMethod.invoke(destList, item);
					}
					prop.getWriteMethod().invoke(dest, destList);
				}
			}else{//自定义类型  Class
				Object d=prop.getPropertyType().newInstance();
				copyProperties(sclazz.getMethod(prop.getReadMethod().getName()).invoke(src),d);
				prop.getWriteMethod().invoke(dest, d);
			}
		}
	}
	
	/**
	 * 是否是包装类型
	 * @param typeName
	 * @return
	 */
	public static boolean isWarpType(String typeName){
		 String[] types = {"java.lang.Integer",  
			        "java.lang.Double",  
			        "java.lang.Float",  
			        "java.lang.Long",  
			        "java.lang.Short",  
			        "java.lang.Byte",  
			        "java.lang.Boolean",  
			        "java.lang.Character",  
			        "java.lang.String"};  
		return ArrayUtils.contains(types, typeName);
	}

}

public class TestA {
	private List<Integer> nums;
	private Person p;
	private Integer age;
	private int big;
	
	private List<Person> data;
}

public class TestB {
	private List<Integer> nums;

	private Integer age;
	private People p;
	private int big;
	
	private List<People> data;
}

public class People {
	private String name;
	private int age;
	
	List<Address> address;
}

public class Person {

	private String name;
	private int age;
	
	List<Address> address;
}

public class Address {

	private String addNo;
	private String addName;
}

• 
• 大小: 26.7 KB

• 查看图片附件