1. Introduction
1.介绍。
This cookbook illustrates how to make use of Hamcrest matchers to work with and test collections.
本手册说明了如何利用Hamcrest匹配器来处理和测试集合。
The format of the cookbook is example focused and practical – no extraneous details and explanations necessary.
烹饪书的格式是以实例为中心的和实用的 – 没有多余的细节和解释。
First, let’s do a quick static import to cover most of the utility APIs we’re going to use next:
首先，让我们做一个快速的静态导入，以涵盖我们接下来要使用的大部分实用API。
import static org.hamcrest.Matchers.*;2. The Cookbook
2.食谱。
check if single element is in a collection
检查单个元素是否在一个集合中
List<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, hasItem("cd"));
assertThat(collection, not(hasItem("zz")));check if multiple elements are in a collection
检查一个集合中是否有多个元素
List<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, hasItems("cd", "ef"));check all elements in a collection
检查一个集合中的所有元素
– with strict order
– 具有严格的秩序。
List<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, contains("ab", "cd", "ef"));– with any order
– 任何订单均可享受。
List<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, containsInAnyOrder("cd", "ab", "ef"));check if collection is empty
检查集合是否为空
List<String> collection = Lists.newArrayList();
assertThat(collection, empty());check if array is empty
检查阵列是否为空
String[] array = new String[] { "ab" };
assertThat(array, not(emptyArray()));check if Map is empty
检查地图是否为空
Map<String, String> collection = Maps.newHashMap();
assertThat(collection, equalTo(Collections.EMPTY_MAP));check if Iterable is empty
检查Iterable是否为空
Iterable<String> collection = Lists.newArrayList();
assertThat(collection, emptyIterable());check size of a collection
检查一个集合的大小
List<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, hasSize(3));checking size of an iterable
检查可迭代的大小
Iterable<String> collection = Lists.newArrayList("ab", "cd", "ef");
assertThat(collection, Matchers.<String> iterableWithSize(3));check condition on every item
每个项目的检查条件
List<Integer> collection = Lists.newArrayList(15, 20, 25, 30);
assertThat(collection, everyItem(greaterThan(10)));3. Conclusion
3.结论。
This format is an experiment – I’m publishing some of my internal development cookbooks on a given topic – Google Guava and now Hamcrest. The goal is to have this information readily available online – and to add to it whenever I run into a new useful example.
这种格式是一种尝试–我正在发布一些关于特定主题的内部开发食谱–Google Guava和现在的Hamcrest。我们的目标是让这些信息可以随时在线获取–并且每当我遇到一个新的有用的例子时，就会对它进行补充。
The implementation of all these examples and code snippets can be found over on GitHub – this is a Maven-based project, so it should be easy to import and run as it is.