Question

I am implementing an example here

I need the output json to name the array.

{"files":[]} instead of just {[]} which is what I’m currently getting as output. What do I need to do to add a name to the array?

 @GET
 @Path("/{key}/meta")
public Response redirect(@PathParam("key") String key) throws IOException {
BlobKey blobKey = new BlobKey(key);
BlobInfo info = blobInfoFactory.loadBlobInfo(blobKey);

String name = info.getFilename();
long size = info.getSize();
String url = "/rest/file/" + key; 
FileMeta meta = new FileMeta(name, size, url);

List<FileMeta> metas = Lists.newArrayList(meta);
GenericEntity<List<FileMeta>> entity = new GenericEntity<List<FileMeta>>(metas) {};
return Response.ok(entity).build();

}

Answer 1

You need your Entity Class to contain an instance of List<FileMeta> called files to have that JSON Output.

public Class EntityClass
{
  private List<FileMeta> files;
  //Getter and Setter Methods.
}

Here’s what you need to have in redirect method.

@GET
@Path("/{key}/meta")
@Produces(MediaType.APPLICATION_JSON)
public Response redirect(@PathParam("key") String key) throws IOException {
BlobKey blobKey = new BlobKey(key);
BlobInfo info = blobInfoFactory.loadBlobInfo(blobKey);

String name = info.getFilename();
long size = info.getSize();
String url = "/rest/file/" + key; 
FileMeta meta = new FileMeta(name, size, url);

List<FileMeta> meta = Lists.newArrayList(meta);
EntityClass entity= new EntityClass();
entity.setFiles(meta);
return Response.ok(entity).build();
}

PS: Additionally, you need to configure POJOMapping in your web.xml.

<init-param>
  <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
  <param-value>true</param-value>
</init-param>