代码记录(需求：根据店铺等级和店铺到某个点的距离进行排序，其中店铺等级由高到低，距离由近及远)
需要排序的对象Store,Store.java
package com.zhipengs.work.test; import java.io.Serializable; /**
* 实体类或DTO
*
* @author zhipengs
*/
public class Store implements Serializable { private static final long serialVersionUID = -1947476757586351017L; private double distance;// 店铺到某个经纬度(点)的距离--距离某个固定的点越近,排序优先级越高
private int sgrade;// 店铺等级--等级越高,排序优先级越高 public Store(double distance, int sgrade) {
super();
this.distance = distance;
this.sgrade = sgrade;
} public double getDistance() {
return distance;
} public void setDistance(double distance) {
this.distance = distance;
} public int getSgrade() {
return sgrade;
} public void setSgrade(int sgrade) {
this.sgrade = sgrade;
} @Override
public int hashCode() {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(distance);
result = prime * result + (int) (temp ^ (temp >>> 32));
result = prime * result + sgrade;
return result;
} @Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Store other = (Store) obj;
if (Double.doubleToLongBits(distance) != Double
.doubleToLongBits(other.distance))
return false;
if (sgrade != other.sgrade)
return false;
return true;
} @Override
public String toString() {
return "Store [distance=" + distance + ", sgrade=" + sgrade + "]";
} }
自定义Comparator,StoreComparator.java
package com.zhipengs.work.test; import java.util.Comparator; /**
* 自定义StoreComparator,实现Comparator接口,重写compare方法
*
* @author zhipengs
*/
public class StoreComparator implements Comparator<Store> { @Override
public int compare(Store o1, Store o2) {
int ret = 0;
// 店铺等级由高到低
int sg = o2.getSgrade() - o1.getSgrade();
if (sg != 0) {
ret = sg > 0 ? 1 : -1;
} else {
// 店铺距离由近及远
sg = (o1.getDistance() - o2.getDistance()) > 0 ? 1 : -1;
if (sg != 0) {
ret = sg > 0 ? 1 : -1;
}
}
return ret;
} }
测试类Main.java
package com.zhipengs.work.test; import java.util.Set;
import java.util.TreeSet; /**
* 测试多条件排序TreeSet--Comparator
*
* @author zhipengs
*/
public class Main { public static void main(String[] args) {
// 先用TreeSet按自定义排序规则排序并控制size大小,再转为有序List遍历进行其它操作或处理
Set<Store> storeSet = new TreeSet<Store>(new StoreComparator());
storeSet.add(new Store(1, 0));
storeSet.add(new Store(2, 1));
storeSet.add(new Store(5, 1));
storeSet.add(new Store(9, 2));
storeSet.add(new Store(3, 0));
storeSet.add(new Store(6, 0));
storeSet.add(new Store(4, 1));
storeSet.add(new Store(7, 2));
storeSet.add(new Store(0, 0));
storeSet.add(new Store(8, 1));
int sgrade = -1;
// 打印排序后的结果
for (Store s : storeSet) {
if (sgrade != s.getSgrade() && -1 != sgrade) {
System.out.println("------------------------------");
}
System.out.println(s);
sgrade = s.getSgrade();
}
}
}
测试结果：
Store [distance=7.0, sgrade=2]
Store [distance=9.0, sgrade=2]
------------------------------
Store [distance=2.0, sgrade=1]
Store [distance=4.0, sgrade=1]
Store [distance=5.0, sgrade=1]
Store [distance=8.0, sgrade=1]
------------------------------
Store [distance=0.0, sgrade=0]
Store [distance=1.0, sgrade=0]
Store [distance=3.0, sgrade=0]
Store [distance=6.0, sgrade=0]