java - 使用 MockMultipartHttpServletRequest 进行单元测试(在 ItemInputStream.makeAvailable 中抛出 NullPointerException)

Question

我编写了一个转换器类，它采用 HttpServletRequest 并将其转换为另一种类型，该类型包含指向来自 servlet 请求的 InputStream 的指针。 (这个想法是从请求处理中抽象传入的传输协议(protocol)，因此我也可以从 FTP 编写一个类似的转换器，例如。)

现在我正在尝试为此编写单元测试，但遇到了问题。我已经设法找出正确的样板来创建有效的多部分 HTTP 请求(使用 Spring 类 MockMultipartHttpServletRequest 和 MockMultipartFile)，但现在我在 initialize() 中得到一个 NullPointerException。我的方法UploadRequest类(class)。我猜问题是 MockMultipartHttpServletRequest 中的流以某种方式没有正确初始化，但我不知道我应该做些什么。

我们将不胜感激地接受任何建议!

这是堆栈跟踪:

java.lang.NullPointerException
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:976)
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:886)
    at java.io.InputStream.read(InputStream.java:82)
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:96)
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:66)
    at org.apache.commons.fileupload.MultipartStream.readBodyData(MultipartStream.java:592)
    at org.apache.commons.fileupload.MultipartStream.discardBodyData(MultipartStream.java:618)
    at org.apache.commons.fileupload.MultipartStream.skipPreamble(MultipartStream.java:637)
    at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.findNextItem(FileUploadBase.java:984)
    at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:965)
    at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)
    at org.apache.commons.fileupload.servlet.ServletFileUpload.getItemIterator(ServletFileUpload.java:148)
    at com.ooyala.UploadRequest.initialize(UploadRequest.java:51)
    at com.ooyala.UploadRequestTest.testCreateFromServletRequest(UploadRequestTest.java:57)

这是我的转换器类的简化版本:

public class UploadRequest {
  private Map<String, String> params;
  private InputStream strIn;
  private Logger Log = Logger.getLogger(UploadRequest.class.getName());

  public UploadRequest()
  {
    params = new HashMap<String, String>();
  }

  public void initialize(HttpServletRequest sRequest, 
                         ServletFileUpload upload)
    throws IOException, FileUploadException
  {
    Enumeration<String> paramNames = sRequest.getParameterNames();
    while (paramNames.hasMoreElements()) {
      String pName = paramNames.nextElement();
      params.put(pName, sRequest.getParameter(pName));
    }
    params.put("request_uri", sRequest.getRequestURI());

    FileItemIterator iter = upload.getItemIterator(sRequest);
    while (iter.hasNext()) {
      FileItemStream item = iter.next();
      try {
        if (!item.isFormField()) {
          // Skip form fields
          params.put("original_file_name", item.getName());
          strIn = item.openStream();
        } 
      } catch (IOException ex) {
        Log.severe("File uploading exception: " + ex.getMessage());
        throw ex;
      }
    }
  }

这是单元测试:

import org.springframework.mock.web.MockMultipartHttpServletRequest;
import org.springframework.mock.web.MockMultipartFile;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
// etc.... other imports

@RunWith(JMock.class)
public class UploadRequestTest {
  private UploadRequest upRequest;

  @Before
    public void setUp()
    {
      context.setImposteriser(ClassImposteriser.INSTANCE);
      upRequest = new UploadRequest();
    }

  @Test
    public void testCreateFromServletRequest()
      throws IOException, FileUploadException
    {
      String text_contents = "hello world";

      MockMultipartHttpServletRequest sRequest = 
        new MockMultipartHttpServletRequest();
      sRequest.setMethod("POST");
      String boundary = generateBoundary();
      String contentType = "multipart/form-data; boundary="+boundary;
      sRequest.setContentType(contentType);
      sRequest.setRequestURI("/foo");
      sRequest.addParameter("test_param","test_value");
      sRequest.addFile(
        new MockMultipartFile("file1","test_upload.txt","text/plain",
          text_contents.getBytes()));

      ServletFileUpload upload = new ServletFileUpload();
      assertTrue(upload.isMultipartContent(sRequest));

      upRequest.initialize(sRequest, upload);
    }
}

Answer 1

我有同样的问题，我用谷歌搜索但没有答案。我插入了库中的源代码，你需要发送内容，随便什么。库可能需要在 skip 方法中检查它是否为 null

MockMultipartHttpServletRequest request
request.setContent("whatever".getBytes());

为其他人张贴在这里