集合工具类CollectionUtil

 

package com.yung.ppapi.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.fastjson.JSON;
import com.yung.ppapi.integration.dto.SiteDTO;

public class CollectionUtil {
	
	private static final Logger logger = LoggerFactory.getLogger(CollectionUtil.class);
	
	/**
	 * 使用序列化方法，实现深层复制，性能不高
	 * @param srcList
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static <T> List<T> deepCopy(List<T> srcList) {  
	    try {
			ByteArrayOutputStream byteOut = new ByteArrayOutputStream();  
			ObjectOutputStream out = new ObjectOutputStream(byteOut);  
			out.writeObject(srcList);  
			out.close();
			
			ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());  
			ObjectInputStream in = new ObjectInputStream(byteIn);  
			return (List<T>) in.readObject();
		} catch (Exception e) {
			logger.error("deepCopy method error：", e);
		}  
	    return null;
	} 
	
//	public static void main(String[] args) {
//		List<SiteDTO> srcList  = new ArrayList<SiteDTO>();
//		SiteDTO site1 = new SiteDTO();
//		site1.setSiteId("1");
//		srcList.add(site1);
//		SiteDTO site2 = new SiteDTO();
//		site2.setSiteId("2");
//		srcList.add(site2);
//		List<SiteDTO> desList = deepCopy(srcList);
//		List<SiteDTO> subSiteList = srcList.subList(0, 1);
//		System.out.println("srcList=" + JSON.toJSONString(srcList));
//		System.out.println("desList=" + JSON.toJSONString(desList));
//		System.out.println("subSiteList=" + JSON.toJSONString(subSiteList));
//		site1.setSiteName("name1");
//		System.out.println("srcList=" + JSON.toJSONString(srcList));
//		System.out.println("desList=" + JSON.toJSONString(desList));
//		System.out.println("subSiteList=" + JSON.toJSONString(subSiteList));
//		subSiteList.clear();
//		System.out.println("srcList=" + JSON.toJSONString(srcList));
//		System.out.println("desList=" + JSON.toJSONString(desList));
//		System.out.println("subSiteList=" + JSON.toJSONString(subSiteList));
//	}
}