集合sort方法的使用
Collections.sort方法可以对集合进行排序，它有两个参数arg0：要排序的集合；arg1：实现了比较接口的类。下面是具体代码：

import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.List;import org.apache.log4j.Logger;public class LinkSort implements Comparator<LinkSort>{Logger logger=Logger.getLogger(LinkSort.class); public LinkSort(){super();}public LinkSort(String key,String url,int linkCount){this.key=key;this.url=url;this.linkCount=linkCount;}private String key;private String url;private int linkCount;public int getLinkCount() {return linkCount;}public void setLinkCount(int linkCount) {this.linkCount = linkCount;}public String getKey() {return key;}public void setKey(String key) {this.key = key;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}/** * 排序方法 * 根据点击次数进行排序   linkCount * **/@Overridepublic int compare(LinkSort arg0,LinkSort arg1){if(arg0.getLinkCount()>=arg1.getLinkCount()){return 0;}else{return 1;}}/** * 生成json格式 * @return String json 格式  {UserManager=/wmba/user/user_queryUserInfos.action} **/public String linkSortToJSON(List<LinkSort> list){if(list.size()>0){//排序Collections.sort(list, new LinkSort());StringBuffer sb=new StringBuffer();sb.append("{");for(LinkSort ls : list){sb.append(ls.getKey()).append(":").append(ls.getUrl()).append(ls.getLinkCount()).append(",\n");}//去掉最后一个","号   并加上"}"String temp=sb.toString().substring(0,sb.toString().length()-1)+"}";logger.debug(temp);return temp;}return "false";}public static void main(String[] args) {List<LinkSort> list=new ArrayList<LinkSort>();list.add(new LinkSort("en_US_link","/wmba/user/user_addUser2.action",3));list.add(new LinkSort("en_US_link","/wmba/user/user_addUser1.action",6));list.add(new LinkSort("en_US_link","/wmba/user/user_addUser3.action",1));list.add(new LinkSort("en_US_link","/wmba/user/user_addUser4.action",2));list.add(new LinkSort("en_US_link","/wmba/user/user_addUser5.action",5));LinkSort linksort=new LinkSort();System.out.println(linksort.linkSortToJSON(list));}}

最后输出：

{en_US_link:/wmba/user/user_addUser1.action6,
en_US_link:/wmba/user/user_addUser5.action5,
en_US_link:/wmba/user/user_addUser2.action3,
en_US_link:/wmba/user/user_addUser4.action2,
en_US_link:/wmba/user/user_addUser3.action1,}