我想使用TreeMap实现创建数据集合,其中String为键,TreeSet为值,并使用自己的Mycomparator实例进行排序。它不能包含重复值,因此不能包含TreeMap。
private TreeMap<String, TreeSet<String>> tree_map = null;
public constructorTreeMap() {
tree_map = new TreeSet<String>()new MyComparator();
我无法正确地实例化,该怎么办?
然后如何将多个字符串添加到TreeSet中?
感谢任何帮助,=)
我希望下面的示例可以使您的工作变得简单:
TreeMap<String, TreeSet<String>> treeMap = null;
// First you instantiate your TreeMap
treeMap = new TreeMap<String, TreeSet<String>>();
// Next you create your TreeSet value which you can instantiate with your comparator
TreeSet<String> value = new TreeSet<String>(myComparator);
value.add("FOO");
value.add("BAR");
// Then you can insert that TreeSet as value in your TreeMap
treeMap.put("your-string-key", value);
尽管您可能在实例化treeMap时考虑使用Set<String>
接口类,这使其更通用:
TreeMap<String, Set<String>> treeMap = new TreeMap<String, Set<String>>();
您的代码的语法有误。应该是这样的:
private TreeMap<String, TreeSet<String>> tree_map = null;
public SynoniemenBeheer() {
tree_map = new TreeMap<>();
TreeSet<String> tree_set = new TreeSet<>(new MyComparator());
tree_map.put("foo", tree_set);
}
并将一些元素添加到已经存在的TreeSet <>中,您可以执行以下操作:
if (tree_map.get("foo") == null) { //null check and fill only if necessary
tree_map.put("foo", new TreeSet<>());
}
tree_map.get("foo").add("foo-foo");
首先实例化树形图:
TreeMap<String, TreeSet<String>> map = new TreeMap<>();
然后实例化要放入地图中的树集:
TreeSet set = new TreeSet<String>(comparator);
然后将要添加的值添加到集合中:
Collections.addAll(set, "value1","value2","value3");
然后将集合放入地图中:
map.put("key", set);