根据id获取它的子id

/**
* 获取子级主题域
*/
List<String> list2 = new ArrayList<String>();
public List<String> getAll(String id,List<ScanSubjectArea> list){
Iterator iter = list.iterator();
while(iter.hasNext()){
ScanSubjectArea subjectArea = (ScanSubjectArea)iter.next();
if(id.equals(subjectArea.getParentId())){
list2.add(subjectArea.getId());
getAll(subjectArea.getId(),list);
}
}
return list2;
}