2015-06-28 71 views
1

我正在嘗試使用org.hamcrest.Matchers.contains(java.util.List<Matcher<? super E>>),但編譯器告訴我它無法解析該方法。Hamcrest Matchers包含與匹配器列表

我甚至試圖通過Hamcrest here給出的例子,但我得到相同的編譯錯誤:

assertThat(Arrays.asList("foo", "bar"), contains(Arrays.asList(equalTo("foo"), equalTo("bar")))); 

Error:(13, 9) java: no suitable method found for assertThat(java.util.List<java.lang.String>,org.hamcrest.Matcher<java.lang.Iterable<? extends java.util.List<org.hamcrest.Matcher<java.lang.String>>>>) 
method org.hamcrest.MatcherAssert.<T>assertThat(T,org.hamcrest.Matcher<? super T>) is not applicable 
    (actual argument org.hamcrest.Matcher<java.lang.Iterable<? extends java.util.List<org.hamcrest.Matcher<java.lang.String>>>> cannot be converted to org.hamcrest.Matcher<? super java.util.List<java.lang.String>> by method invocation conversion) 
method org.hamcrest.MatcherAssert.<T>assertThat(java.lang.String,T,org.hamcrest.Matcher<? super T>) is not applicable 
    (cannot instantiate from arguments because actual and formal argument lists differ in length) 
method org.hamcrest.MatcherAssert.assertThat(java.lang.String,boolean) is not applicable 
    (actual argument java.util.List<java.lang.String> cannot be converted to java.lang.String by method invocation conversion) 

我試着投的第二個參數匹配器<?超級列表<字符串> >

assertThat(Arrays.asList("foo", "bar"), (Matcher<? super List<String>>)contains(Arrays.asList(equalTo("foo"), equalTo("bar")))); 

但後來我得到另一個編譯錯誤:

Error:(16, 88) java: inconvertible types 
required: org.hamcrest.Matcher<? super java.util.List<java.lang.String>> 
found: org.hamcrest.Matcher<java.lang.Iterable<? extends java.util.List<org.hamcrest.Matcher<java.lang.String>>>> 

有沒有辦法正確地使用這種方法嗎?

+0

該匹配器會檢查列表是否包含某個元素,但是您傳遞的是匹配器列表。 'Arrays.asList(「foo,」bar「)''是一個'List ',所以它不會包含'asList(equalTo(」foo「),equalTo(」bar「))'。測試? – yshavit

+0

請閱讀該方法的Javadoc(參見提供的鏈接) Matchers.contains(列表)應該驗證第一個參數中的每個項目是否滿足第二個參數中相應的匹配器 –

+0

'assertThat(Arrays .asList(「foo」,「bar」),contains(Arrays.asList(equalTo(「foo」),equalTo(「bar」)));'工作;你有一些奇怪的靜態導入包含或equalTo? – beresfordt

回答

2

問題是Arrays.asList(equalTo("foo"), equalTo("bar"));會給你List<Matcher<String>>的類型,但你真的想要List<Matcher<? super String>>。您必須明確指定類型:

assertThat(str, 
    contains(Arrays.<Matcher<? super String>>asList(
     equalTo("foo"), 
     equalTo("bar")))); 
+0

That did it。謝謝Kai。 –

+0

Your're welcome –