我进行了搜索,但找不到有关如何对我自己的通用集合类进行排序的任何答案。
我有这四个类:
第二次编辑 简化的代码,应用了 Evgeniy 的建议,但仍然没有排序,有线:\
轨道类:
public class Track {
private Integer id;
private String interpreter;
private String title;
Track(int id,String interpreter,String title) {
this.id=id;
this.interpreter=interpreter;
this.title=title;
}
public String getInterpreter() {
return this.interpreter;
}
public String getTitle() {
return this.title;
}
public int getID() {
return this.id;
}
public String getCompleteName() {
return this.id+"\t"+this.interpreter.toString()+" - "+this.title.toString();
}
}
TrackContainer 类:
import java.util.ArrayList;
import java.util.Iterator;
public class TrackContainer<T> extends ArrayList<T> {
private static final long serialVersionUID = 1L;
ArrayList<T> arraylist;
TrackContainer() {
arraylist = new ArrayList<T>();
}
public boolean insertTrack(T track) {
if(arraylist.add(track))
return true;
return false;
}
public void listAllTracks(java.util.Iterator<T> iterat) {
while(iterat.hasNext()) {
System.out.println(iterat.next());
}
}
public Iterator<T> iterator() {
// TODO Auto-generated method stub
return arraylist.iterator();
}
}
TrackIDComparator 类:
import java.util.Comparator;
public class TrackIDComparator implements Comparator<Track> {
@Override
public int compare(Track t1, Track t2) {
// TODO Auto-generated method stub
Comparable id1 = (Comparable)(t1.getID());
Comparable id2 = (Comparable)(t2.getID());
return id1.compareTo(id2);
}
}
最后是主类:
import java.util.Collections;
import java.util.Iterator;
public class Main {
public static void main(String[] args) {
TrackContainer<Track> ltc = new TrackContainer<Track>();
ltc.insertTrack(new Track(2,"trackname1","tracktitle1"));
ltc.insertTrack(new Track(1,"trackname2","tracktitle2"));
ltc.insertTrack(new Track(3,"trackname3","tracktitle3"));
System.out.println("unsorted:");
Iterator<Track> it = ltc.iterator();
while(it.hasNext()) {
System.out.println(it.next().getCompleteName());
}
System.out.println("sorted:");
Collections.sort(ltc,new TrackIDComparator());
Iterator<Track> it2 = ltc.iterator();
while(it2.hasNext()) {
System.out.println(it2.next().getCompleteName());
}
}
}
输出:
unsorted: 2 trackname1 - tracktitle1 1 trackname2 - tracktitle2 3 trackname3 - tracktitle3 sorted: 2 trackname1 - tracktitle1 1 trackname2 - tracktitle2 3 trackname3 - tracktitle3
最佳答案
只需将 sort() 方法添加到 TrackContainer
public void sort() {
Collections.sort(arraylist, new TrackIDComparator());
}
更新
不清楚为什么Track是通用的,为什么T id; T口译员;标题;应该有相同的类型。我建议修改设计。无论如何,
class TrackIDComparator
public int compare(Track<T> o1, Track<T> o2) {
if(o1.getID().hashCode() > o2.getID().hashCode())
return 1;
...
不正确,改成
public int compare(Track<T> o1, Track<T> o2) {
Comparable id1 = (Comparable)(o1.getId());
Comparable id2 = (Comparable)(o2.getId());
return id1.compareTo(id2);
}
关于java - 对通用集合进行排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13743478/