`get(key)` Across Multiple Manifests

[briantopping]

Cool library, thanks.

Would be great if the API could return a list of values for a single key, collected across all jars on the classpath. Should be pretty easy. I'd put in a PR, but I'll be doing mine in Scala :/

[briantopping]

In case you're marginally interested. I forgot some of my JavaConversions stuff...

object Main extends App {
  import scala.collection.JavaConversions._

  private val loader: ClassLoader = getClass.getClassLoader
  val paths = for {
    url <- loader.getResources("META-INF/MANIFEST.MF")
    manifest = { val m = new Manifests(); m.append(new StreamsMfs(url.openStream())); m }
    value <- Option(manifest.get("Manifest-Version"))
  } yield value

  paths.foreach(println)
}

[dmarkov]

@yegor256 dispatch this issue please, see par.21

[yegor256]

@briantopping yeah, that's a good idea indeed, we'll try to implement it

[dmarkov]

@nesterov-n can you please help? Keep in mind this. If you have any technical questions, don't hesitate to ask right here; This task's budget is 30 mins. This is exactly how much will be paid when the problem explained above is solved. See this for more information

[nesterov-n]

@yegor256 For now we have Map<String, String> in Manifests.java and values with same key are ovewrriten. Can you help to find out is best way to implement

list of values for a single key, collected across all jars on the classpath

Should we use Map<String, List<String>> to store manifests values? It can broke backward compatibility. Maybe just add separate static methos in Manifests.java ? Something like this

public static List<String> collect(Collection<InputStream> manifests, Object key) {
     // collect and return multiple values here
}

[yegor256]

@nesterov-n yeah, I think we should keep data in Map<String, List>, just like you suggested. we don't need to delete any existing public methods. just introduce a few new ones

[nesterov-n]

@yegor256 But class Manifests.java implements Map<String, String> interface. If we don't change interface to Map<String, List<String>> it's difficult to change underlying map

[yegor256]

@nesterov-n why? internally you will have Map<String,List>, but the method will still expose Map<String,String>

[nesterov-n]

@yegor256 It gives lot of difficulty and dubious code. For example

private final transient Map<String, List<String>> attributes;
....
@Override
    public String remove(final Object key) {
        List<String> removed = this.attributes.remove(key);
        return removed != null ? removed.get(0) : null;
    }

And it's not most complicated case

How can i improve values() implementation?

@Override
    public Collection<String> values() {
        List<String> result = new ArrayList<String>();
        for (List<String> strings : this.attributes.values()) {
            result.add(strings.get(0));
        }
        return result;
    }

And Set<Map.Entry<String, String>> entrySet() has same problems

As for me this code is ugly. If you don't think so I can implement it

[dmarkov]

@nesterov-n the ticket is with you for 15 days already. If it is not finished in the next 48 hours, it will be re-assigned to someone else, see No Obligations principle, this article should help if you're stuck

-30 to your rating, your total score is -43