mocking multipart mime request with mockito

java, junit, mime-message, mockito, web-services

Solution

I think this should work:

final ByteArrayOutputStream os = new ByteArrayOutputStream ();
multiPartResponse.writeTo (os);
final ByteArrayInputStream is = new ByteArrayInputStream (os.toByteArray ());
when(request.getInputStream()).thenReturn(new ServletInputStream() {
        @Override
        public int read() throws IOException {
            return is.read();
        }
    });

Problem

I'm pretty new to Mockito and mocking out servlets for testing. I'm having problems mocking out an HttpServletRequest which sends some form data to my servlet as a MimeMultiPart. In my servlet I call `request.getInputStream()` as follows: ``` mimeMultiPart = new MimeMultipart(new ByteArrayDataSource( request.getInputStream(), Constants.MULTI_PART_FORM_DATA)); ``` When I mock out my input stream I create an entire MimeMultiPart message and then I try to return a ServletInputStream from it in the code below ``` //Helper function to create ServletInputStream private ServletInputStream createServletInputStream(Object object) throws Exception { //create output stream ByteArrayOutputStream byteOut = new ByteArrayOutputStream(); ObjectOutputStream outStream = new ObjectOutputStream(byteOut); //this part no workey outStream.writeObject(object); //create input stream final InputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray()); //create a new ServletInputStream and return it return new ServletInputStream() { @Override public int read() throws IOException { return byteIn.read(); } }; } @Test public void testDoPost() throws Exception { PrintWriter writer; writer = new PrintWriter("testSendMultiPartBatchResponse.txt"); when(response.getWriter()).thenReturn(writer); //this is the mocked request when(request.getInputStream()).thenReturn( createServletInputStream(multiPartResponse)); . . . ``` now when I run this test I receive the following error on `outStream.writeObject(object)`: ``` java.io.NotSerializableException: javax.mail.internet.MimeMultipart at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.writeObject(Unknown Source) . . . ``` it's not necessary to post the rest of the stack trace, I'm pretty sure the problem is that MimeMultiPart is not serializable, but I don't know how to rectify this. Is there another way to mock out the request? I am at a loss :(

Original source