Add artifact download API

components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ArtifactDownloadAPIImpl.java

@@ -52,7 +52,12 @@ public class ArtifactDownloadAPIImpl implements ArtifactDownloadAPI {
         AppmDataHandler dataHandler = APIUtil.getDataHandler();
         try {
             InputStream fileInputStream = dataHandler.getArtifactStream(uuid, fileName);
-            return Response.status(Response.Status.OK).entity(fileInputStream).build();
+            Response.ResponseBuilder response = Response
+                    .ok(fileInputStream, MediaType.APPLICATION_OCTET_STREAM);
+            response.status(Response.Status.OK);
+//            response.type("application/html");
+            response.header("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
+            return response.build();
         } catch (NotFoundException e) {
             String msg = "Couldn't find an application release for UUID: " + uuid + " and file name:  " + fileName;
             log.error(msg, e);

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/util/StorageManagementUtil.java

@@ -130,9 +130,8 @@ public class StorageManagementUtil {
         if (!sourceFile.exists()){
             return null;
         }
-
-        try (InputStream inputStream = new FileInputStream(sourceFile)){
-            return inputStream;
+        try {
+            return new FileInputStream(sourceFile);
         } catch (FileNotFoundException e) {
             String msg = "Couldn't file the file in file path: " + filePath;
             log.error(msg);

components/application-mgt/org.wso2.carbon.device.application.mgt.handler/src/main/java/org/wso2/carbon/device/application/mgt/handler/util/HandlerUtil.java

@@ -207,7 +207,11 @@ public class HandlerUtil {
         resp.setCharacterEncoding("UTF-8");
         proxyResponse.setExecutorResponse(null);
         try (PrintWriter writer = resp.getWriter()) {
-            writer.write(gson.toJson(proxyResponse));
+            if (proxyResponse.getCode() == HttpStatus.SC_OK){
+                writer.write(gson.toJson(proxyResponse.getData()));
+            } else{
+                writer.write(proxyResponse.getData());
+            }
         }
     }