写一条java语句

Question

[code="java"]
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class TestTemp {

/**
 * @param args
 */
public static void main(String[] args) {
    Set<A> set = new HashSet<A>();
    set.add(new A("AAAA"));
    set.add(new A("BBBB"));
    set.add(new A("CCCC"));
    set.add(new A("DDDD"));

    //在此处填入一条语句，实现稳定输出结果：
    /*
     * DDDD
     * CCCC
     * BBBB
     * AAAA
     */
    while(it.hasNext()){
        System.out.println(it.next());
    }
}

}
class A{
String name;
A(String name){
this.name= name;
}
public String toString(){
return name;
}
}
[/code]

Answer 1

[code="java"]java.util.TreeSet ts = new java.util.TreeSet(new java.util.Comparator() {
public int compare(A a, A b) {
return a.toString().compareTo(b.toString());
}
});
ts.addAll(set);
Iterator it = ts.descendingIterator();[/code]
同意 nickkane 的, 觉得一开始不采用 HashSet 才合适