Dropwizard file upload

Question

I have to upload a file from my site yet cnt seem to get it working with drop wizard.

Here is the form from my site.

   <form enctype="multipart/form-data" method="POST" action="UploadFile">
     <input type="file" id="fileUpload" name="file"/>
     <input type="hidden" id="fileName" name="fileName"/>
     <input type="submit" value="Upload"/>
   </form>

How would I go about on the backend to receive the file?

The solution was

    @POST
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    public Response uploadFile(
        @FormDataParam("file") final InputStream fileInputStream,
        @FormDataParam("file") final FormDataContentDisposition contentDispositionHeader) {


    String filePath = uploadLocation + newFileName;
    saveFile(fileInputStream, filePath);
    String output = "File can be downloaded from the following location : " + filePath;

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

}

private void saveFile(InputStream uploadedInputStream,
        String serverLocation) {
    try {
            OutputStream outputStream = new FileOutputStream(new      File(serverLocation));
            int read = 0;
            byte[] bytes = new byte[1024];

            outputStream = new FileOutputStream(new File(serverLocation));
            while ((read = uploadedInputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
            outputStream.flush();
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }   

Answer 1

You could do the saving to the server in lesser number of lines using nio

java.nio.file.Path outputPath = FileSystems.getDefault().getPath(<upload-folder-on-server>, fileName);
Files.copy(fileInputStream, outputPath);

Also, if you're using 0.7.0-rc2, you will need this dependency in your pom.xml

<dependency>
<groupId>com.sun.jersey.contribs</groupId>
<artifactId>jersey-multipart</artifactId>
<version>1.18</version>
</dependency>

Answer 2

With Dropwizard 0.9.2 you have to add the dependency:

<dependency>
    <groupId>io.dropwizard</groupId>
    <artifactId>dropwizard-forms</artifactId>
    <version>${dropwizard.version}</version>
    <type>pom</type>
</dependency>

as well as register the multipart feature:

    environment.jersey().register(MultiPartFeature.class);

Answer 3

Ensure that you add dropwizard-forms dependency to your pom.xml

<dependency>
    <groupId>io.dropwizard</groupId>
    <artifactId>dropwizard-forms</artifactId>
    <version>${dropwizard.version}</version>
    <type>pom</type>
</dependency>

Your resource seems good, Anyhow I've uploaded an example project for uploading files with Dropwizard - https://github.com/juanpabloprado/dw-multipart

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(
        @FormDataParam("file") InputStream uploadedInputStream,
        @FormDataParam("file") FormDataContentDisposition fileDetail) throws MessagingException, IOException {

    String uploadedFileLocation = "C:/Users/Juan/Pictures/uploads/" + fileDetail.getFileName();

    // save it
    writeToFile(uploadedInputStream, uploadedFileLocation);
    String output = "File uploaded to : " + uploadedFileLocation;
    return Response.ok(output).build();
}

// save uploaded file to new location
private void writeToFile(InputStream uploadedInputStream, String uploadedFileLocation) throws IOException {
    int read;
    final int BUFFER_LENGTH = 1024;
    final byte[] buffer = new byte[BUFFER_LENGTH];
    OutputStream out = new FileOutputStream(new File(uploadedFileLocation));
    while ((read = uploadedInputStream.read(buffer)) != -1) {
        out.write(buffer, 0, read);
    }
    out.flush();
    out.close();
}