像往常一样,这里介绍的所有代码片段都可以在GitHub上找到。 原文链接:https://www.baeldung.com/java-combine-two-lists-into-map
importjava.util.ArrayList;importjava.util.List;publicclassListCombination{publicList<String>combineLists(List<String>listA,List<String>listB){List<String>resultList=newArrayList<>();for(StringitemA:listA){for(StringitemB:listB){StringcombinedItem=itemA+itemB;resultList.add(combinedItem);}}returnresult...
2.3 调用方法拼接list 现在,我们可以在主方法中调用combineLists方法,将多个list拼接成一个实体,并进行操作。如下所示: publicstaticvoidmain(String[]args){List<String>list1=newArrayList<>();list1.add("A");list1.add("B");List<Integer>list2=newArrayList<>();list2.add(1);list2.add(2);Entityent...
TheaddAll()method is the simplest way toappend all of the elements from the given list to the end of another list. Using this method, we cancombine multiple lists into a single list. Merge arraylists example ArrayList<String>listOne=newArrayList<>(Arrays.asList("a","b","c"));ArrayList<...
2. Intersection of Two Lists of Strings Let's create twoLists ofStrings with some intersection — both having some duplicated elements: List<String> list = Arrays.asList("red","blue","blue","green","red"); List<String> otherList = Arrays.asList("red","green","green","yellow"); ...
assertEquals(2, differences.size()); assertThat(differences).containsExactly("Tom", "John"); 6. Handling Duplicate Values Now let’s look at finding the differences when two lists contain duplicated values. To achieve this,we need to remove the duplicate elements from the first list, precisely...
如果采用同步调用的方式,那么以上程序则需要 3 + 2 共 5s 的时间。 使用supplyAsync 创建 CompletableFuture CompletableFuture 提供了更轻巧的工厂方法 View Code 对两个 CompletableFuture 的整合 compose 与 combine compose,在一个 CompletableFuture 执行完毕后,将执行结果通过 Function 传递给下一个 Future 进行处理...
Example 2–1 Looking Up a Connection Factory // Create the environment for constructing the initial JNDI // naming context. Hashtable env = new Hashtable(); // Store the environment attributes that tell JNDI which initial context // factory to use and where to find the provider.// ...
Note:You can combine the two types of customizations. For example, you could include a reference to an external binding customizations file in an inline annotation. However, you cannot declare both an inline and external customization on the same schema element. ...
Item 32: Combine generics and varargs judiciously 可变参数方法和泛型在一起工作时不那么协调,因此需要特别注意。 可变参数方法的设计属于一个抽象泄漏,即当你调用可变参数方法时,将创建一个数组来保存参数;该数组本应是实现细节,却是可见的。因此会出现编译器警告。 下面是一个可变参数和泛型混用,造成类型错误的例...