Question

如果我有Set的集合。我必须在Collection中找到相同的对，即：

收集：

设置{Object_A，Object_B，Object_C}
设置{Object_A，Object_B，Object_F}

如何在Collection＆gt;中找到pair：Object_A-Object_B？？什么Java库可以用于此目的？

Answer 1

Set<String> setA = new HashSet<>(Arrays.asList("one", "two", "three"));
Set<String> setB = new HashSet<>(Arrays.asList("one", "two", "four"));

Set<String> intersection = new HashSet<>(setA);
intersection.retainAll(setB);
System.out.println("intersection: " + intersection);

Answer 2

以下示例将有所帮助。

import java.util.Collection;
import java.util.HashSet;
import java.util.Arrays;

class Identical {
      public static void main( String  [] args ) {

          Collection<String> listOne = Arrays.asList("Object_A","Object_B",
                                                    "Object_C");

          Collection<String> listTwo = Arrays.asList("Object_A","Object_B",
                                                    "Object_F");

          Collection<String> similar = new HashSet<String>( listOne );
          Collection<String> different = new HashSet<String>();
          different.addAll( listOne );
          different.addAll( listTwo );

          similar.retainAll( listTwo );
          different.removeAll( similar );

      }
}

Answer 3

如果您想使用lib，可以使用 Google Guava ，只需调用：

Sets.intersection(setOne, setTwo);

请参阅Sets . intersection()。

例如：

Sets.SetView<String> intersectionView = Sets.intersection(
    ImmutableSet.of("Object_A", "Object_B", "Object_C"),
    ImmutableSet.of("Object_A", "Object_B", "Object_D"));
Set<String> intersectionSet = intersectionView.immutableCopy();

intersectionView将仅作为"Object_A"和"Object_B"视图作为元素，由两个原始集支持。 intersectionSet将是一个不可变的交集。

根据您的需求（可变性等），请参阅Guava文档以获取更多详细信息和替代方案。

如何在Collection中找到相同的对？

3 个答案: