在java中,如果要對集合對象或數(shù)組對象進(jìn)行排序,需要實(shí)現(xiàn)Comparator接口以達(dá)到我們想要的目標(biāo)。
接下來我們模擬下在集合對象中對日期屬性進(jìn)行排序
一、實(shí)體類Step
package com.ljq.entity;/** * 運(yùn)號單流程 * * @author Administrator * */public class Step{ /** 處理時(shí)間 */ private String acceptTime = ""; /** 快件所在地點(diǎn) */ private String acceptAddress = ""; public Step() { super(); } public Step(String acceptTime, String acceptAddress) { super(); this.acceptTime = acceptTime; this.acceptAddress = acceptAddress; } public String getAcceptTime() { return acceptTime; } public void setAcceptTime(String acceptTime) { this.acceptTime = acceptTime; } public String getAcceptAddress() { return acceptAddress; } public void setAcceptAddress(String acceptAddress) { this.acceptAddress = acceptAddress; }}
二、實(shí)現(xiàn)Comparator接口
package com.ljq.entity;import java.util.Comparator;import java.util.Date;import com.ljq.util.UtilTool;/** * 對Step類進(jìn)行排序 * * @author Administrator * */public class StepComparator implements Comparator<Step>{ /** * 如果o1小于o2,返回一個(gè)負(fù)數(shù);如果o1大于o2,返回一個(gè)正數(shù);如果他們相等,則返回0; */ @Override public int compare(Step o1, Step o2) { Date acceptTime1=UtilTool.strToDate(o1.getAcceptTime(), null); Date acceptTime2=UtilTool.strToDate(o2.getAcceptTime(), null); //對日期字段進(jìn)行升序,如果欲降序可采用before方法 if(acceptTime1.after(acceptTime2)) return 1; return -1; }}
三、測試
package junit;import java.util.Collection;import java.util.Collections;import java.util.List;import org.junit.Test;public class StepComparatorTest { @Test public void sort() throws Exception{ List<Step> steps=new ArrayList<Step>; //對集合對象進(jìn)行排序 StepComparator comparator=new StepComparator(); Collections.sort(steps, comparator); if(steps!=null&&steps.size()>0){ for(Step step:steps){ System.out.println(step.getAcceptAddress()); System.out.println(step.getAcceptTime()); } } }}
|
新聞熱點(diǎn)
疑難解答
圖片精選