How to get multipartentity from httpservletrequest

Question

I am trying to invoke a webservice from java spring controller. Below is the code

private void storeImages(MultipartHttpServletRequest multipartRequest) {
    DefaultHttpClient httpClient = new DefaultHttpClient();
    HttpPost postRequest = new HttpPost(
                    "http://localhost:8080/dream/storeimages.htm");
    MultipartFile multipartFile1 = multipartRequest.getFile("file1");
    MultipartEntity multipartEntity = new MultipartEntity(
                    HttpMultipartMode.BROWSER_COMPATIBLE);
    multipartEntity.addPart("file1",
                    new ByteArrayBody(multipartFile1.getBytes(),
                                    multipartFile1.getContentType(),
                                    multipartFile1.getOriginalFilename()));
    postRequest.setEntity(multipartEntity);
    HttpResponse response = httpClient.execute(postRequest);
    if (response.getStatusLine().getStatusCode() != 201) {
        throw new RuntimeException("Failed : HTTP error code : "
                        + response.getStatusLine().getStatusCode());
    }
}

Above is just partial code. I am trying to determine how to retrieve this on the server side. On the server side i have the following Spring controller code

@RequestMapping(value = "/storeimages.htm", method = RequestMethod.POST)
public ModelAndView postItem(HttpServletRequest request,
                HttpServletResponse response) {
    logger.info("Inside /secure/additem/postitem.htm");
    try {
        // How to get the MultipartEntity object here. More specifically i
        // want to get back the Byte array from it
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return new ModelAndView("success");
}

I executed this code and my control is going to the server side. But i am stuck on how to get back the byte array from the multipartentity object.

Edited requirement: Here is the requirement. User uploads the images from website (This is done and working) The control goes to the Spring controller after form submit (This is done and working) In Spring controller I am using Multipart to get the content of the form. (This is done and working) Now i want to call a webservices which will send the image byte array to image server.(This needs to be done) On the image server, i want to receive this webservice request get all the fields from HTTPServlerRequest, store the images and return(This needs to be done)

Answer 1

Finally resolved it. Here is what worked for me.

Client side

private void storeImages(HashMap<String, MultipartFile> imageList) {
    try {
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost postRequest = new HttpPost("http://localhost:8080/dream/storeimages.htm");

        MultipartEntity multipartEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);

        Set set = imageList.entrySet(); 
        Iterator i = set.iterator(); 
        while(i.hasNext()) { 
            Map.Entry me = (Map.Entry)i.next(); 
            String fileName = (String)me.getKey();
            MultipartFile multipartFile = (MultipartFile)me.getValue();
            multipartEntity.addPart(fileName, new ByteArrayBody(multipartFile.getBytes(), 
                    multipartFile.getContentType(), multipartFile.getOriginalFilename()));
        } 
        postRequest.setEntity(multipartEntity);
        HttpResponse response = httpClient.execute(postRequest);

        if (response.getStatusLine().getStatusCode() != 200) {
            throw new RuntimeException("Failed : HTTP error code : "
                    + response.getStatusLine().getStatusCode());
        }

        BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));

        String output;
        while ((output = br.readLine()) != null) {
            logger.info("Webservices output - " + output);
        }
        httpClient.getConnectionManager().shutdown();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Server side

@RequestMapping(value = "/storeimages.htm", method = RequestMethod.POST)
public void storeimages(HttpServletRequest request, HttpServletResponse response)
{
    logger.info("Inside /secure/additem/postitem.htm");
    try
    {
        //List<Part> formData = new ArrayList(request.getParts());
        //Part part = formData.get(0);
        //Part part = request.getPart("file1");
        //String parameterName = part.getName();
        //logger.info("STORC IMAGES - " + parameterName);
        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;

        Set set = multipartRequest.getFileMap().entrySet(); 
        Iterator i = set.iterator(); 
        while(i.hasNext()) { 
            Map.Entry me = (Map.Entry)i.next(); 
            String fileName = (String)me.getKey();
            MultipartFile multipartFile = (MultipartFile)me.getValue();
            logger.info("Original fileName - " + multipartFile.getOriginalFilename());
            logger.info("fileName - " + fileName);
            writeToDisk(fileName, multipartFile);
        } 
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
    }
}

public void writeToDisk(String filename, MultipartFile multipartFile)
{
    try
    {
        String fullFileName = Configuration.getProperty("ImageDirectory") + filename;
        FileOutputStream fos = new FileOutputStream(fullFileName);
        fos.write(multipartFile.getBytes());
        fos.close();
    }
    catch (Exception ex)
    {
        ex.printStackTrace();
    }
}

Answer 2

In my project, we used to use MultipartParser from com.oreilly.servlets to handle HttpServletRequests corresponding to multipart requests, as follows:

// Should be able to handle multipart requests upto 1GB size.
MultipartParser parser = new MultipartParser(aReq, 1024 * 1024 * 1024);
// If the content type is not multipart/form-data, this will be null.
if (parser != null) {
    Part part;
    while ((part = parser.readNextPart()) != null) {
        if (part instanceof FilePart) {
            // This is an attachment or an uploaded file.
        }
        else if (part instanceof ParamPart) {
            // This is request parameter from the query string
        }
    }
}

Hope this helps.