Loading static html files using Akka-http Java

问题

I've been struggling to get a static file to load from a simple aka-http Java server. I've tried a number of options, but I always get the following error:

[ERROR] [09/07/2018 11:52:06.258] [AkkaRestApiApp-akka.actor.default-dispatcher-4] [akka.actor.ActorSystemImpl(AkkaRestApiApp)] Error during processing of request: 'java.lang.NullPointerException (No error message supplied)'. Completing with 500 Internal Server Error response. To change default exception handling behavior, provide a custom ExceptionHandler.
java.lang.NullPointerException
at akka.http.scaladsl.server.directives.FileAndResourceDirectives.$anonfun$getFromResource$1(FileAndResourceDirectives.scala:106)
...

Here are two examples of the various routes I tried:

return route(path("docs", () ->
        getFromResource("resources/index.html")
      ));

return pathPrefix("docs", () ->
    route(
        pathEnd(() -> getFromResource("resources/index.html"))
));

The following line correctly prints the path to the file:

try {
       System.out.println(MyDocService.class.getClassLoader().getResource("resources/index.html").toURI());
    } catch (URISyntaxException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

I assume the path I pass to getFromResource method should be the same. Since the vast majority of akka-http google searches return Scala examples, I'm sure I'm just making some stupid mistake writing a Java version. I found an older StackOverflow post about issues loading static resources when the path contains spaces, so I made sure there are no spaces in the path to my service. Thanks in advance for any pointers.

回答1:

I was able to get this to work using getFromFile instead of getFromResource. It's still not clear why getFromResource does not work, but I'm able to workaround the problem.

来源：https://stackoverflow.com/questions/52226298/loading-static-html-files-using-akka-http-java

标签

java

akka-http