smigniot/ServeFiles.java Secret

## ServeFiles.java
package com.example.jaxrs;


import org.apache.commons.io.IOUtils;

import javax.ws.rs.*;
import javax.ws.rs.core.Response;
import java.io.*;
import java.util.logging.Logger;

import static javax.ws.rs.core.MediaType.*;

public class ServeFiles {

    // @POST // Correction #2
    @GET     // How can you POST a form, in json format and expect a redirect ?
    @Path("/{loginId}")
    // @Produces(MULTIPART_FORM_DATA)   // Correction #1
    @Produces(APPLICATION_OCTET_STREAM) // Produce bytes only
    @Consumes(APPLICATION_JSON)
    // public Response downloadExportedFile(@PathParam("loginId") String loginId, ExportFileDTO fileDetails) throws IOException {
    public Response downloadExportedFile(@PathParam("loginId") String loginId) throws IOException {
        Logger.getAnonymousLogger().info("Request");
        File exportFolder = new File("C://directory");

        File[] listOfFiles = exportFolder.listFiles();
        for (File listOfFile : listOfFiles) {
            //if (listOfFile.getName().equals(fileDetails.getFileName())) {
                // Commented for now => it serves the first file
                InputStream is = new FileInputStream(listOfFile.getAbsolutePath());
                byte[] buffer = IOUtils.toByteArray(is);
                Logger.getAnonymousLogger().info("Serving !");
                return Response.ok(listOfFile)
                        .header("content-disposition", "attachment; filename=" + new File(listOfFile.getName()).getName())
                        .type(APPLICATION_OCTET_STREAM_TYPE).build();
            //}
        }
        Logger.getAnonymousLogger().info("Failure");
        return Response.serverError().build();
    }
}

## test.html
<html><body>

<script type="text/javascript">

//
// See https://stackoverflow.com/questions/9718102/how-does-jquery-post-deal-with-content-disposition-attachment#answer-9718122
//
// 1. If it's a GET, it is downloaded
// 2. If it's a POST, it has to be a standard form,
//    with    enctype='multipart/form-data'
//    or with enctype='application/x-www-form-urlencoded'
// 3. Else :
//
//    There is simply no way to have
//    * a FORM
//    * perform a POST
//    * in Content-Type: application/json
//    That doesn't exist
//
// So the client side (React as you said) IS makeing the call
// And as it's a _programmatic_ call the user does not get
// prompted to save the file
//
// You will have to let us know more of your
// client-side architecture or change your way of serving the file
//
function makePost() {
	var url = "./rest-prefix/johndoe";
	var xhr = new XMLHttpRequest();
	xhr.open("POST", url, true);
	xhr.setRequestHeader("Content-type", "application/json");
	xhr.onreadystatechange = function () {
		if (xhr.readyState == 4 && xhr.status == 200) {
			// User is NEVER prompted
		}
	}
	var data = JSON.stringify({"name":"example.txt"});
	xhr.send(data);
}
</script>

<button onclick="makePost()">TEST</button>


</body></html>
	package com.example.jaxrs;


	import org.apache.commons.io.IOUtils;

	import javax.ws.rs.*;
	import javax.ws.rs.core.Response;
	import java.io.*;
	import java.util.logging.Logger;

	import static javax.ws.rs.core.MediaType.*;

	public class ServeFiles {

	// @POST // Correction #2
	@GET // How can you POST a form, in json format and expect a redirect ?
	@Path("/{loginId}")
	// @Produces(MULTIPART_FORM_DATA) // Correction #1
	@Produces(APPLICATION_OCTET_STREAM) // Produce bytes only
	@Consumes(APPLICATION_JSON)
	// public Response downloadExportedFile(@PathParam("loginId") String loginId, ExportFileDTO fileDetails) throws IOException {
	public Response downloadExportedFile(@PathParam("loginId") String loginId) throws IOException {
	Logger.getAnonymousLogger().info("Request");
	File exportFolder = new File("C://directory");

	File[] listOfFiles = exportFolder.listFiles();
	for (File listOfFile : listOfFiles) {
	//if (listOfFile.getName().equals(fileDetails.getFileName())) {
	// Commented for now => it serves the first file
	InputStream is = new FileInputStream(listOfFile.getAbsolutePath());
	byte[] buffer = IOUtils.toByteArray(is);
	Logger.getAnonymousLogger().info("Serving !");
	return Response.ok(listOfFile)
	.header("content-disposition", "attachment; filename=" + new File(listOfFile.getName()).getName())
	.type(APPLICATION_OCTET_STREAM_TYPE).build();
	//}
	}
	Logger.getAnonymousLogger().info("Failure");
	return Response.serverError().build();
	}
	}
	<html><body>

	<script type="text/javascript">

	//
	// See https://stackoverflow.com/questions/9718102/how-does-jquery-post-deal-with-content-disposition-attachment#answer-9718122
	//
	// 1. If it's a GET, it is downloaded
	// 2. If it's a POST, it has to be a standard form,
	// with enctype='multipart/form-data'
	// or with enctype='application/x-www-form-urlencoded'
	// 3. Else :
	//
	// There is simply no way to have
	// * a FORM
	// * perform a POST
	// * in Content-Type: application/json
	// That doesn't exist
	//
	// So the client side (React as you said) IS makeing the call
	// And as it's a _programmatic_ call the user does not get
	// prompted to save the file
	//
	// You will have to let us know more of your
	// client-side architecture or change your way of serving the file
	//
	function makePost() {
	var url = "./rest-prefix/johndoe";
	var xhr = new XMLHttpRequest();
	xhr.open("POST", url, true);
	xhr.setRequestHeader("Content-type", "application/json");
	xhr.onreadystatechange = function () {
	if (xhr.readyState == 4 && xhr.status == 200) {
	// User is NEVER prompted
	}
	}
	var data = JSON.stringify({"name":"example.txt"});
	xhr.send(data);
	}
	</script>

	<button onclick="makePost()">TEST</button>



	</body></html>