Comparator 比较器示例
作者:互联网
在java中,如果要对集合对象或数组对象进行排序,需要实现Comparator接口以达到我们想要的目标。
接下来我们模拟下在集合对象中对日期属性进行排序
一、实体类Step
/**
* 运号单流程
*/
public class Step{
/** 处理时间 */
private String acceptTime = "";
/** 快件所在地点 */
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、实现Comparator接口
import java.util.Comparator;
import java.util.Date;
import com.ljq.util.UtilTool;
/**
* 对Step类进行排序
*/
public class StepComparator implements Comparator<Step>{
/**
* 如果o1小于o2,返回一个负数;如果o1大于o2,返回一个正数;如果他们相等,则返回0;
*/
@Override
public int compare(Step o1, Step o2) {
Date acceptTime1=UtilTool.strToDate(o1.getAcceptTime(), null);
Date acceptTime2=UtilTool.strToDate(o2.getAcceptTime(), null);
//对日期字段进行升序,如果欲降序可采用before方法
if(acceptTime1.after(acceptTime2)) return 1;
return -1;
}
}
三、测试
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>;
//对集合对象进行排序
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());
}
}
}
}
标签:String,Comparator,示例,比较,acceptTime,Step,import,public,acceptAddress 来源: https://www.cnblogs.com/hhddd-1024/p/15305032.html