Sending and receiving files via RESTful web services in Java

In this blog, I'll show you how to pass the content of a file to a RESTful web service and have it stored on the server it was received. First write your CXF service and annotate it as follows:

@POST
@Path("saveFile")
@Produces({MediaType.APPLICATION_JSON})
@Consumes({MediaType.MULTIPART_FORM_DATA})
public UploadFile saveFile(MultipartBody body) {
     List<Attachment> attachments = body.getAllAttachments();
     Attachment att = attachments.get(0);
     File destinationFile = new File("/tmp/log/fileX.txt");

     try {
          att.transferTo(destinationFile);
     } 
     catch (IOException ioe) {
          ioe.printStackTrace();
     }
     UploadFile savedFile = new UploadFile();
     savedFile.setFilename("/tmp/log/fileX.txt");
     return savedFile;
}

To call this service, I am using Apache httpcomponents package. Add the following dependencies to your pom.xml:

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.0-beta2</version>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>4.0-beta2</version>
        </dependency>

And here is the test snippet to call the web service:

    @Test
    public void restSaveFile()  {
        String url = "http://localhost:8080/mywebapp/services/";
        ResponseEntity<AuthenticationToken> authToken = restClient.authenticate(url + "authenticate");
        String token = null;
        if (authToken != null)
            token = authToken.getBody().getToken();
        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url + "saveFile");
            // Assuming ~mywebapp/src/test/resource/data/test-file.txt
            FileBody body = new FileBody(new File(Thread.currentThread().getContextClassLoader().getResource("data/test-file.txt").getFile()));
            StringBody comment = new StringBody("Test data for saving a file.");
            httpPost.addHeader("X-Auth-Token", token);
            httpPost.addHeader("Content-Type", MediaType.MULTIPART_FORM_DATA_VALUE);       
            MultipartEntity requestEntity = new MultipartEntity();
            requestEntity.addPart("file", body);
            requestEntity.addPart("comment", comment);
            httpPost.setEntity(requestEntity);        
            System.out.println("Executing request " + httpPost.getRequestLine());
            HttpResponse response = httpclient.execute(httpPost);
            HttpEntity responseEntity = response.getEntity();
            System.out.println("----------------------------------------------");
            System.out.println(response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("Response content length: " + responseEntity.getContentLength());
                System.out.println("Response content type: " + responseEntity.getContentType().getValue());
            }
            if (responseEntity != null) {           
                responseEntity.consumeContent();
            }
            System.out.println("----------------------------------------------");
        } 
        catch (Exception ex) {
            ex.printStackTrace();
        }        
    }