通过JAX-RS使用RESTful Web服务的文件下载列表

Question

taken from, http://www.concretepage.com/webservices/download-file-using-restful-web-services-jax-rs , here is the code to download a File from a jax-rs rest service

@Path("/restwb") 
public class FileResource {
    @GET
    @Path("/download/{fname}/{ext}")
        @Produces(MediaType.APPLICATION_OCTET_STREAM)
    public Response  downloadFile(@PathParam("fname") String fileName,@PathParam("ext") String fileExt){
        File file = new File("C:/temp/"+fileName+"."+fileExt);
        ResponseBuilder rb = Response.ok(file);
        rb.header("Content-Disposition", "attachment; filename=" + file.getName());
        Response response = rb.build();
        return response;
    }
} 

My question now is what should the response look like in order to download a list of File objects (ArrayList)?

Can we just write:

List<File> lFiles = new ArrayList<File>();
...
ResponseBuilder rb = Response.ok(lFiles);

Answer 1

You can not download multiple files in the same request. If you need to download multiple files you have to create an archive then download the archived file.

This is because raw bytes of the file are sent in the HTTP Response, and HTTP headers are used for how to translate the content you can only set one set of headers HTTP response.