java:集合的自定义多重排序

问题：

有一个乱序的对象集合，要求先按对象的属性A排序（排序规则由业务确定，非A-Z或0-9的常规顺序），相同A属性的记录，按根据属性B排序（排序规则，同样由业务确定，非常规顺序） -前提：业务规则是明确的

示例：

FSUData对象定义

package acc.test;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.junit.Test;

public class FSUSortTest {

Map<String, Integer> airportDic = new HashMap<String, Integer>();
Map<String, Integer> fsuDic = new HashMap<String, Integer>();

@Test
public void test() {

// 先定义顺序规则
airportDic.put("成都", 1);
airportDic.put("上海", 2);
airportDic.put("法兰克福", 3);

fsuDic.put("RCS", 1);
fsuDic.put("RCF", 2);
fsuDic.put("TFD", 3);
fsuDic.put("DEP", 4);
fsuDic.put("DLV", 5);

// 建一个待排序的目标"数组"
List<FSUData> target = new ArrayList<FSUData>();

target.add(new FSUData("法兰克福", "RCF"));
target.add(new FSUData("法兰克福", "DLV"));

target.add(new FSUData("成都", "DEP"));
target.add(new FSUData("成都", "RCS"));

target.add(new FSUData("上海", "DEP"));
target.add(new FSUData("上海", "RCF"));

System.out.println("排序前：" + target);

// 排序
FsuComparator fsuComparator = new FsuComparator(airportDic, fsuDic);
Collections.sort(target, fsuComparator);

System.out.println("排序后：" + target);
}

private class FsuComparator implements Comparator<FSUData> {

Map<String, Integer> airportMap;
Map<String, Integer> fsuMap;

public FsuComparator(Map<String, Integer> airportMap,
Map<String, Integer> fsuMap) {
this.airportMap = airportMap;
this.fsuMap = fsuMap;
}

public int compare(FSUData s1, FSUData s2) {

// 从顺序规则Map里，取出"排序值"
Integer airportOrder1 = airportMap.get(s1.getAirport());
Integer airportOrder2 = airportMap.get(s2.getAirport());

// 如果Airport相同，则比较FSUCode
if (airportOrder1 == airportOrder2) {
Integer fsuOrder1 = fsuMap.get(s1.getFsuCode());
Integer fsuOrder2 = fsuMap.get(s2.getFsuCode());
return fsuOrder1.compareTo(fsuOrder2);
}

return airportOrder1.compareTo(airportOrder2);
}
}

}

View Code
思路：先将"业务排序规则" 转换成 "常规有序规则"，然后再利用Comparator接口实现比较