Java多列组合排序器一个例子

import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.LinkedList;
/**
* 多列组合排序器
*Title:
*
*Description:
*
*Copyright: Copyright (c) 2005
*
*Company:
*
* @author not attributable
* @version 1.0
*/

public class CompositeComparator implements Comparator{
/** in the condition list, comparators' priority decrease from head to tail */
private List comparators = new LinkedList();

/** get the comparators, you can manipulate it as need.*/
public List getComparators(){
return comparators;
}

/** add a batch of comparators to the condition list */
public void addComparators(Comparator[] comparatorArray){
if(comparatorArray == null){
return;
}

for(int i = 0; i < comparatorArray.length; i++){

comparators.add(comparatorArray[i]);
}
}

/** compare by the priority */
public int compare(Object o1, Object o2){
for(Iterator iterator = comparators.iterator(); iterator.hasNext();){
Comparator comparator = (Comparator)iterator.next();

int result = comparator.compare(o1, o2);

if(result != 0){
return result;
}
}

return 0;
}
}



//多列排序；按镇，终端
CompositeComparator myComparator = new CompositeComparator();
myComparator. addComparators(
new Comparator[]{
new Comparator() {
public int compare(Object a, Object b) {
DisplayForm aObj, bObj;
aObj = (DisplayForm) a;
bObj = (DisplayForm) b;
String aStr = (String) aObj.get("COUNTY_NO");
String bStr = (String) bObj.get("COUNTY_NO");
return aStr.compareTo(bStr);
}
}

, new Comparator(){
public int compare(Object a, Object b) {
DisplayForm aObj, bObj;
aObj = (DisplayForm) a;
bObj = (DisplayForm) b;
String aStr = (String) aObj.get("DDP_ID");
String bStr = (String) bObj.get("DDP_ID");
return aStr.compareTo(bStr);
}
}
});
java.util.Collections.sort(listResult,myComparator);

对java对象集合进行排序