我最感兴趣的是对集合中Bean属性的断言，相信这也是最具实用的断言，可见hamcrest偏偏在这方面做得很弱啊，以下是我的一断测试代码：
@Test
public void testNotSeniorQuery() throws Exception {
List<ParsedQueryParam> parsedQueryParams = queryParamParser.parse(request);
assertThat(parsedQueryParams, notNullValue());
assertThat(parsedQueryParams, hasSize(6));
assertThat(parsedQueryParams,
hasItem(hasProperty("aaa",is("a"))));
}
以上代码直接通不过编译，具体解决方法参见：
https://weblogs.java.net/blog/johnsmart/archive/2008/04/on_the_subtle_u.html
也即，以上测试代码必须改成：
@Test
public void testNotSeniorQuery() throws Exception {
List parsedQueryParams = queryParamParser.parse(request);//这儿直接用List
assertThat(parsedQueryParams, notNullValue());
assertThat(parsedQueryParams, hasSize(6));
assertThat((List<Object>)parsedQueryParams, //这儿将List cast 为List<Object>
hasItem(hasProperty("aaa",is("a"))));
}
虽然这样可以通过编译了，但是我还有更多类似于以下的断言集合中Bean级联属性的需求：
即ParsedQueryParam类包含了一个QueryParam,QueryParam中拥有paramName及paramValue属性，我希望hamcrest能够支持以下的代码：
@Test
public void testNotSeniorQuery() throws Exception {
List parsedQueryParams = queryParamParser.parse(request);
assertThat(parsedQueryParams, notNullValue());
assertThat(parsedQueryParams, hasSize(6));
assertThat((List<Object>)parsedQueryParams,
hasItem(hasProperty("queryParam.paramName",is("userId1"))));//失败，无法正确断言！！
}
可是这样无法成功运行，报如下错误：
引用
java.lang.NoSuchMethodError: org.hamcrest.Matcher.describeMismatch(Ljava/lang/Object;Lorg/hamcrest/Description;)V
at org.hamcrest.core.IsCollectionContaining.matchesSafely(IsCollectionContaining.java:31)
at org.hamcrest.core.IsCollectionContaining.matchesSafely(IsCollectionContaining.java:14)
at org.hamcrest.TypeSafeDiagnosingMatcher.matches(TypeSafeDiagnosingMatcher.java:55)
at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:12)
at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:8)
at com.hsit.euler.eqengine.query.parser.impl.QueryParamParserImplTest.testNotSeniorQuery(QueryParamParserImplTest.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
at org.testng.internal.MethodInvocationHelper$1.runTestMethod(MethodInvocationHelper.java:200)
at org.unitils.UnitilsTestNG.run(UnitilsTestNG.java:103)
此路不通，我就试着换成如下方式：
@Test
public void testNotSeniorQuery() throws Exception {
List parsedQueryParams = queryParamParser.parse(request);
assertThat(parsedQueryParams, notNullValue());
assertThat(parsedQueryParams, hasSize(6));
assertThat((List<Object>)parsedQueryParams,
hasItem(hasProperty("queryParam",hasProperty("paramName"))));//这样可以成功断言！
}
但是以上断言只是断言属性的存在性，如果我断言属性值，即又歇菜了！
@Test
public void testNotSeniorQuery() throws Exception {
List parsedQueryParams = queryParamParser.parse(request);
assertThat(parsedQueryParams, notNullValue());
assertThat(parsedQueryParams, hasSize(6));
assertThat((List<Object>)parsedQueryParams,
hasItem(hasProperty("queryParam",hasProperty("paramName",is("userId1")))));//NND 这样不行！
}
一直想找一个可以很好对集合中Bean进行存在性断言或Bean属性值断言的框架，发现hamcrest很让人失望啊。不知列位有没有好的建议，非常感谢！