How to write a REST plugin which handles a file upload?

[Aleksander Kocieniewski]

Hi,

I am trying to write a plugin with REST which uploads a file. All I want now is just to receive a file from client and save it on disk. My code is for now:

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.sun.jersey.multipart.FormDataParam;

@Path("/upload")
public class RESTService {
 
 public RESTService() {}

 @POST
 @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
 @Consumes(MediaType.MULTIPART_FORM_DATA)
 public Response getMessage(@FormDataParam("file") InputStream uploadedInputStream) throws IOException {

 String uploadedFileLocation = "/destination/file.xls";
 
 OutputStreamWriter wr = new FileWriter(new File(uploadedFileLocation));
 InputStreamReader input = new InputStreamReader(uploadedInputStream);
 char[] buffer = new char[1024 * 4];
 long count = 0;
 int n = 0;
 while (-1 != (n = input.read(buffer))) {
 wr.write(buffer, 0, n);
 count += n;
 }
 wr.close();


 String output = "File uploaded to : " + uploadedFileLocation;

 return Response.status(200).entity(output).build();
 }
}

Client sends the file by curl execution:

  curl -D- -u user:pswd -X POST -H "X-Atlassian-Token: no-check" -F "file=@file.xls" http://jira:8080/rest/uploadRestPlugin/1.0/upload

The problem is that, the file saved on disk has got additional headers and a footer:

------------------------------437c56a39444
Content-Disposition: form-data; name="file"; filename="file.xls"
Content-Type: text/plain

[there is the file content]

------------------------------437c56a39444--

How could I retreive a file from InputStream without additional info? In text files it isn't a big problem, but other files cannot be edited (like .xls) by cutting them in a simple way.

I use this library in pom:

 <dependency>
 <groupId>com.sun.jersey.contribs</groupId>
 <artifactId>jersey-multipart</artifactId>
 <version>1.8</version>
 <scope>provided</scope>
 </dependency>

When I add a parameter: @FormDataParam("file") FormDataContentDisposition formDataContentDisposition I got the error:

[c.a.p.r.c.error.jersey.ThrowableExceptionMapper] Uncaught exception thrown by REST service: Exception obtaining parameters
com.sun.jersey.api.container.ContainerException: Exception obtaining parameters
 at com.sun.jersey.server.impl.inject.InjectableValuesProvider.getInjectableValues(InjectableValuesProvider.java:94)
...
Caused by: java.lang.NullPointerException
 at com.sun.jersey.server.impl.inject.InjectableValuesProvider.getInjectableValues(InjectableValuesProvider.java:86)
 ... 208 more

Trying to use (adding dependency in pom) other plugins for REST technologies like:
- com.sun.jersey.multipart.MultiPart 
- org.jboss.resteasy.plugins.providers.multipart.MultipartFormDataInput

give always stacktrace:

com.atlassian.util.concurrent.LazyReference$InitializationException: com.sun.jersey.spi.inject.Errors$ErrorMessagesException

Please help me.

[Hua Soon SIM _Akeles_]

I found a working solution at https://community.atlassian.com/t5/Answers-Developer-Questions/How-to-use-AUI-file-upload/qaq-p/536601

Hope it helps.

[Sam Hall]

Hi Aleksander - Welcome to the community.

Since your question is development related, you can also try asking this over at: https://community.developer.atlassian.com (if you haven't already).

There are a lot of helpful and experienced people over there, so you might get a quicker response.

You can read more about the Developer Community in this article: https://community.atlassian.com/t5/Feedback-Forum-articles/The-Atlassian-Developer-Community/ba-p/459061

[Aleksander Kocieniewski]

Thank you for your reply. I didn't know about forum dedicated for developers. I created a thread there as you suggested.

[Sam Hall]

No problem. Atlassian decided to split, but sadly it's not obvious where people should go to post questions of this nature.

I'd post an answer here as well if I can help, but couldn't in this case.

Someone might reply here too.

[Sam Hall]

Here's a link to the question asked over on the Dev Community, in case people want to follow the trail: https://community.developer.atlassian.com/t/how-to-write-a-rest-plugin-which-handles-a-file-upload/2296