关于集合排序的问题???

[zxycbz]

public static void main(String args[])
{
Map tempMap = new HashMap();
List tempList = new ArrayList();
SunClass a1 = new SunClass("1", "zxy1");
SunClass a6 = new SunClass("6", "zxy6");
SunClass a2 = new SunClass("2", "zxy2");
SunClass a3 = new SunClass("3", "zxy3");

tempList.add(a1);
tempList.add(a2);
tempList.add(a3);
tempList.add(a6);

Collections.sort(tempList);

for (int i = 0; i < tempList.size(); i ++)
{
System.out.println(tempList.get(i));
}
}


排序的时候为什么会出错???

[kissclf]

报的什么错，我估计会出现ClassCastException

[Influence]

SunClass类长什么样啊？有没有实现Comparable接口？

[廊子]

学习

[dreamhunter_lan]

排序有错就是SunClass没有实现Comparable接口，它不晓得怎么给你的对象做比较

[natee]

估计添加a2的时间就出错了，呵呵

[phoenixLotus]

是 要实现comparable接口 因为你list装的是对象。。

[zxycbz]

public class SunClass implements Comparable<SunClass>{

String id ;
String name;


public int compareTo(SunClass o) {
return Integer.valueOf(this.getId()) - Integer.valueOf(o.getId());
}

public String toString() {
return "Cat{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}

public String getId() {
return id;
}

public void setId(String id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public SunClass(String id, String name) {
this.id = id;
this.name = name;
}


搞定了,需要重写Comparable<SunClass> 中的方法

[fuyou001]

SunClass 没实现comparable接口

[时光瞄]

没有实现Comparable接口，支持楼上的

[shenjie1989]

没有实现Comparable接口