PowerMockito - 如何使用带有类型列表的whenNew（）？ [英] PowerMockito - How do I use whenNew() with a typed List?

问题描述

当 new ArrayList< Foo>（）时，我希望PowerMockito返回我的空数组列表 Foo 被称为，但我不知道如何构建声明。具体来说，我希望新的ArrayList< AnyOtherType>（）来创建一个新的列表，如同正常情况一样。

 的ArrayList<富> fooList = new ArrayList< Foo>（）; 
 PowerMockito.whenNew（ArrayList.class）.withParameterTypes（Foo.class）.thenReturn（fooList）; 
  

^这里基本上是我的，但 .withParameterTypes（Foo.class） 不允许我关注 .thenReturn（）。我唯一的选择是 withArguments（firstArgument，additionalArguments）。

这是PowerMock的可能吗？如果是这样，我是否构造它？

编辑：

好的，底层的问题是我需要得到我试图测试的方法，但我不得不嘲笑请求，并且在我试图测试的方法结束时将列表放在请求中。

  inspectionAction.viewInspectionDetailsAjax（mapping，form，request，response）; 
  

这个方法从请求中抽取了一些参数，这个参数是被模拟的（ Mockito.mock（HttpServletRequest.class）; ）。通常在我们的应用程序中，我们将数据放置在会话级变量中。但是由于这个方法被一次调用多次，并且结果会被写入页面，所以每个数据片段都会被存储在请求中：

  request.setAttribute（inspectionAjaxDetails，详情）; 
  

所以我需要一些方法来获取详情 ，这是一个类型化的ArrayList，当 request 被模拟时。

解决方案

简短的回答是：你不能。正如Matt Lachman在评论中指出的那样，你不能捕获类型的泛型，所以你不能得到 List< Foo> c> List< Bar> 和 List< AnyOtherType> 。因为集合的使用太多了，所以尝试使用PowerMock捕获它们几乎总是一个坏主意。

在我的情况下，我需要获得一个给定的List在我试图测试的方法中作为一个属性（映射为< String，Object> ）来模拟 HttpServletRequest 。我必须找到一个不同的解决方案。在我的例子中，它创建了一个非匿名的 Answer 实现，可以在方法运行后从中检索值。我的Mockito调用如下所示：

  RequestAnswer requestAnswer = new RequestAnswer（）; 
 
 Mockito.doAnswer（requestAnswer）.when（request）.setAttribute（Matchers.anyString（），Matchers.anyObject（））; 
 
 ArrayList< Foo> details =（ArrayList< Foo>）requestAnswer.getAttribute（foo）; 
  

我的RequestAnswer类实现答案< Object> ，其最重要的方法如下所示：

  @Override 
 public Object answer（InvocationOnMock invocation）throws Throwable { 
 Object [] args = invocation.getArguments（）; 
 String methodName = invocation.getMethod（）。getName（）; 
 if（setAttribute.equals（methodName））{
 String key =（String）args [0]; 
 Object value = args [1]; 
 attributes.put（key，value）; 
} else if（getAttribute.equals（methodName））{
 String key =（String）args [0]; 
返回attributes.get（key）; 
} else if（getParameter.equals（methodName））{
 String key =（String）args [0]; 
返回parameters.get（key）; 
} 
返回null; 
} 
  

剩下的只是几个Maps和getters和setters。

I want PowerMockito to return my empty array-list of Foos when new ArrayList<Foo>() is called, but I am not sure how to construct the statement. Specifically, I want new ArrayList<AnyOtherType>() to create a new list as normal.

ArrayList<Foo> fooList = new ArrayList<Foo>();
PowerMockito.whenNew(ArrayList.class).withParameterTypes(Foo.class).thenReturn(fooList);

^ Here's basically what I have, but .withParameterTypes(Foo.class) does not allow me to follow with a .thenReturn(). My only option is withArguments(firstArgument, additionalArguments).

Is this possible with PowerMock, and if so, how do I construct it?

EDIT:

Ok, the underlying problem is I need to get the result of the method I'm trying to test, but I had to mock the request, and the list is placed in the request at the end of the method I'm trying to test.

inspectionAction.viewInspectionDetailsAjax(mapping, form, request, response);

This method pulls a couple of parameters from the request, which is mocked (Mockito.mock(HttpServletRequest.class);). Usually in our app we place data on a session-level variable. But since this method is called several times at once and the results ajax'd into the page, each piece of data is stored in the request instead:

request.setAttribute("inspectionAjaxDetails", details);

So I need some way to get details, which is a typed ArrayList, when request is mocked.

解决方案

The short answer is: You can't. As Matt Lachman pointed out in the comments, you can't capture the generics of a type, so you can't get List<Foo> without also getting List<Bar> and List<AnyOtherType>. Because collections are used so heavily, it is almost always a bad idea to try to capture them with PowerMock.

In my case, I needed to get a List that was given to a mocked HttpServletRequest as an attribute (mapped <String, Object>) in the method I was trying to test. I had to find a different solution. In my case, it was to create a non-anonymous implementation of Answer that I could retrieve values from after the method was run. My Mockito call looked like this:

RequestAnswer requestAnswer = new RequestAnswer();

Mockito.doAnswer(requestAnswer).when(request).setAttribute(Matchers.anyString(), Matchers.anyObject());

ArrayList<Foo> details = (ArrayList<Foo>) requestAnswer.getAttribute("foo");

My RequestAnswer class implements Answer<Object>, and its most important method looks like this:

@Override
public Object answer(InvocationOnMock invocation) throws Throwable {
    Object[] args = invocation.getArguments();
    String methodName = invocation.getMethod().getName();
    if ("setAttribute".equals(methodName)) {
        String key = (String) args[0];
        Object value = args[1];
        attributes.put(key, value);
    } else if ("getAttribute".equals(methodName)) {
        String key = (String) args[0];
        return attributes.get(key);
    } else if ("getParameter".equals(methodName)) {
        String key = (String) args[0];
        return parameters.get(key);
    }
    return null;
}

The rest was just a couple of Maps and getters and setters.

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