spring : get response as Multipart File from REST WebService - spring

Question

I am creating POC for RESTFUL Web service using Spring 4.0. Requirement is to receive MultipartFile as Response from REST WEB-Service.
REST Service Controller
#RequestMapping(value="/getcontent/file", method=RequestMapping.post)
public MultipartFile getMultipartAsFileAsObject() {
File file = new File("src/test/resources/input.docx");
FileInputStream input = new FileInputStream(file);
MultipartFile multipartFile = new MockMultipartFile("file",file.getName(),
"application/docx", IOUtils.toByteArray(input));
return multipartFile
}
I call this service using third party Clients and Apache Http Client as well. kindly have a look on output.
Using Third party REST client ie. Postman
output looks like Json -
{
"name" : "file",
"originalfilename" : "sample.docx",
"contentType" : "application/docx",
"content" : [
82,
101,
97,
100,
101,
32,
32,
.
.
.
.
.
]
}
Apache HTTP Client Sample code
private static void executeClient() {
HttpClient client = new DefaultHttpClient();
HttpPost postReqeust = new HttpPost(SERVER_URI);
try{
// Set Various Attributes
HttpResponse response = client.execute(postReqeust) ;
//Verify response if any
if (response != null)
{
InputStream inputStream = response.getEntity().getContent();
byte[] buffer = new byte[inputStream.available()];
inputStream.read(buffer);
OutputStream outputStream = new FileOutputStream
(new File("src/main/resource/sample.docx"));
outputStream.write(buffer);
outputStream.flush();
outputStream.close();
}
}
catch(Exception ex){
ex.printStackTrace();
}
Output of Apache Http client
file is getting Created but It is empty. (0 bytes).

Answer 1

I found some interesting answers from multiple stackoverflow questions.
Links are given below
file downloading in restful web services
what's the correct way to send a file from REST web service to client?
For Sending single file : (copied from above sources)
#GET
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response getFile() {
File file = ... // Initialize this to the File path you want to serve.
return Response.ok(file, MediaType.APPLICATION_OCTET_STREAM)
.header("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"" ) //optional
.build();
}
For Sending Zip file : (copied from above sources)
1) Approach First :
You can use above method to send any file / Zip.
private static final String FILE_PATH = "d:\\Test2.zip";
#GET
#Path("/get")
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response getFile() {
File file = new File(FILE_PATH);
ResponseBuilder response = Response.ok((Object) file);
response.header("Content-Disposition", "attachment; filename=newfile.zip");
return response.build();
}
2) Approach Second :
#GET
#Path("/get")
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public StreamingOutput helloWorldZip() throws Exception {
return new StreamingOutput(){
#Override
public void write(OutputStream arg0) throws IOException, WebApplicationException {
// TODO Auto-generated method stub
BufferedOutputStream bus = new BufferedOutputStream(arg0);
try {
Thread.currentThread().getContextClassLoader().getResource("");
File file = new File("d:\\Test1.zip");
FileInputStream fizip = new FileInputStream(file);
byte[] buffer2 = IOUtils.toByteArray(fizip);
bus.write(buffer2);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
}