我正在用 Java 创建 RDF 语句。我有两个 HashSet，并且想将它们都添加到 TreeSet 中。这是我的代码:
Collection<Statement> model = new HashSet<Statement>();
Collection<Statement> model_1 = new HashSet<Statement>();
Collection<Statement> treeSet = new TreeSet<Statement>();
将一些语句存储到这两个哈希集中后，我将它们都添加到 TreeSet 中:这是代码:
treeSet.addAll(model);
treeSet.addAll(model_1);
for (Statement _state : treeSet)
System.out.println(_state);
我认为第一个哈希集“model”将被添加到TreeSet中，然后分别添加第二个哈希集“model_1”。当我循环遍历 TreeSet 时，它们似乎没有排序。任何人都可以帮助我如何对 TreeSet 的元素进行排序，以便我可以分别添加第一个 HashSet 和第二个 HashSet 。
最佳答案
TreeSet 将根据您放入的元素进行排序，而不是按照您放入元素的顺序。如果您不需要，一个简单的 List 可能就足够了散列能力，或者可能是 LinkedHashSet (在迭代时保持插入顺序)
Hash table and linked list implementation of the Set interface, with predictable iteration order. This implementation differs from HashSet in that it maintains a doubly-linked list running through all of its entries. This linked list defines the iteration ordering, which is the order in which elements were inserted into the set (insertion-order). Note that insertion order is not affected if an element is re-inserted into the set. (An element e is reinserted into a set s if s.add(e) is invoked when s.contains(e) would return true immediately prior to the invocation.)
关于java - 如何将两个HashSet分别添加到有序TreeSet中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19836349/