Question

I am using spring 3.0 org.springframework.web.multipart.commons.CommonsMultipartFile for file uploading. i want write down unit test case for file upload using Mockito.

Following is my controller class

private RegistrationService registrationService;

@RequestMapping(method = RequestMethod.POST)
    public String create(Registration registration, BindingResult result,ModelMap model)
            throws NumberFormatException, Exception {
        
        File uploadedFile = uploadFile(registration);
        List<Registration> userDetails = new ArrayList<Registration>();
        processUploadedFile(uploadedFile,userDetails);
        
        model.addAttribute("userDetails", userDetails);
        
        return "Registration";
    }
    
    private File uploadFile(Registration registration) {
        
        Date dt = new Date();
        SimpleDateFormat format = new SimpleDateFormat("MM_dd_yyyy_HH_mm_ss");
        File uploadedFile = new File(uploadFileLocation
                + registration.getFileData().getOriginalFilename() + "."
                + format.format(dt));
         
        try {
            registration.getFileData().transferTo(uploadedFile);
            
        } catch (IllegalStateException e) {
            logger.error("Error occurred while uploading file", e);  
        } catch (IOException e) {
            logger.error("Error occurred while uploading file", e);
        }   
        
        return uploadedFile;
    }

    private void processUploadedFile(File uploadedFile, List<Registration> userDetails)
            throws NumberFormatException, Exception {

        registrationService.processFile(uploadedFile, userDetails);
    }

Registration class

public class Registration {
    private String name;
    private CommonsMultipartFile fileData;
    
    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public CommonsMultipartFile getFileData() {
        return fileData;
    }

    public void setFileData(CommonsMultipartFile fileData) {
        this.fileData = fileData;
    }
}

My Service class method

public void processFile(File uploadedFile,
            List<Registration> userDetails) throws NumberFormatException,
            Exception {     

        String record = "";

        try {

            FileWriter fstream = new FileWriter(outputFileLocation
                    + uploadedFile.getName());
            BufferedWriter out = new BufferedWriter(fstream);

            BufferedReader br = new BufferedReader(new FileReader(
                    uploadedFile.getAbsolutePath()));

            while ((record = br.readLine()) != null) {
                String[] requesterUser = record.split(",");

                if (insertUserToDB(requesterUser, userDetails) > 0)
                    out.write(record + ", Yes");
                else
                    out.write(record + ", No");

                out.newLine();

            }
            out.flush();
            out.close();

        } catch (FileNotFoundException e) {
            logger.error("Error occured while processing file",  e);
        } catch (IOException e) {
            
            logger.error("Error occured while processing file",  e);
        }

        
    }

How to Unit Test it?I am new to Mockito.

Edit

I have write down Test method for testing above code, but it return null for multipartFile. How should I test above service class processFile method?

@Test
       public void testProcessFile() {
        private static final String TEST_FILE = "c:\\user.csv";
        MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
        MockMultipartHttpServletRequest mockMultipartHttpServletRequest = (MockMultipartHttpServletRequest)request;
        MultipartFile multipartFile = (MultipartFile) mockMultipartHttpServletRequest.getFile(TEST_FILE);

        Registration registration=new Registration();
        registration.setFileData(multipartFile);
        RegistrationService.processFile(uploadedFile, userDetails);
        }

I am new to JUnit and mockito. Any help or pointer really appreciated.

Answer 1

You might want to consider using Spring’s Mock implementation (org.springframework.mock.web.MockMultipartFile) rather than creating a mock using Mockito.