NullPointerException from vertx core in StaticHandlerImpl.getFile

[Brian Saastad]

We using vert.x 3.2.1.  The app is in a two-host cluster behind a load balancer, simple http server.  Sometimes it will stop honoring http requests with the following exception.  It does not happen on both hosts at the same time -- once it starts, the affected host is dead while the other continues to work fine.  Has anyone seen this except

vert.x-eventloop-thread-2] ERROR io.vertx.core.impl.ContextImpl - Unhandled exception
java.lang.NullPointerException
    at io.vertx.ext.web.impl.Utils.pathOffset(Utils.java:209)
    at io.vertx.ext.web.handler.impl.StaticHandlerImpl.getFile(StaticHandlerImpl.java:506)
    at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendStatic(StaticHandlerImpl.java:174)
    at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendDirectory(StaticHandlerImpl.java:222)
    at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendStatic$2(StaticHandlerImpl.java:191)
    at io.vertx.ext.web.handler.impl.StaticHandlerImpl$$Lambda$122/1352176477.handle(Unknown Source)
    at io.vertx.core.impl.FutureImpl.checkCallHandler(FutureImpl.java:158)
    at io.vertx.core.impl.FutureImpl.setHandler(FutureImpl.java:100)
    at io.vertx.core.impl.ContextImpl.lambda$null$16(ContextImpl.java:305)
    at io.vertx.core.impl.ContextImpl$$Lambda$24/301425080.handle(Unknown Source)
    at io.vertx.core.impl.ContextImpl.lambda$wrapTask$18(ContextImpl.java:335)
    at io.vertx.core.impl.ContextImpl$$Lambda$25/465546070.run(Unknown Source)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:358)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357)
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112)
    at java.lang.Thread.run(Thread.java:745)

[Khen Ofek]

Yes, I also encountered this exception with 3.2.1
My setup was just a single server without load balance.

I was hoping that 3.3.0 will fix this issue.

Khen Ofek

[Paulo Lopes]

Can you create a reproducer project so we can investigate?

Thanks!

[Jody Schering]

I'm also seeing this issue in vertx 3.3.2 in io.vertx.ext.web.impl.Utils.pathOffset(Utils.java:214) It's failing on line 214 in the pathOffset method which is:

String routePath = context.currentRoute().getPath();

It appears the currentRoute() returns null so the getPath() fails with the NullPointerException. 

I'd be happy to to create a reproducer project but I'm not sure when or what causes this? What is this code trying to do and when is it called? I see no visible impact to the application and it seems to happen randomly.

Exception:

Aug 09, 2016 12:27:51 PM [SEVERE] io.vertx.core.impl.ContextImpl: Unhandled exception

java.lang.NullPointerException

        at io.vertx.ext.web.impl.Utils.pathOffset(Utils.java:214)

        at io.vertx.ext.web.handler.impl.StaticHandlerImpl.getFile(StaticHandlerImpl.java:518)

        at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendStatic(StaticHandlerImpl.java:176)

        at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendDirectory(StaticHandlerImpl.java:218)

        at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendStatic$0(StaticHandlerImpl.java:189)

        at io.vertx.ext.web.handler.impl.StaticHandlerImpl$$Lambda$132/2045304508.handle(Unknown Source)

        at io.vertx.core.impl.FutureImpl.checkCallHandler(FutureImpl.java:158)

        at io.vertx.core.impl.FutureImpl.setHandler(FutureImpl.java:100)

        at io.vertx.core.impl.ContextImpl.lambda$null$1(ContextImpl.java:315)

        at io.vertx.core.impl.ContextImpl$$Lambda$27/1545623630.handle(Unknown Source)

        at io.vertx.core.impl.ContextImpl.lambda$wrapTask$3(ContextImpl.java:359)

        at io.vertx.core.impl.ContextImpl$$Lambda$28/458691103.run(Unknown Source)

        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:339)

        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:393)

        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:742)

        at java.lang.Thread.run(Thread.java:745)

Code:

public static String pathOffset(String path, RoutingContext context) {

    int prefixLen = 0;

    String mountPoint = context.mountPoint();

    if (mountPoint != null) {

      prefixLen = mountPoint.length();

    }

    String routePath = context.currentRoute().getPath();

    if (routePath != null) {

      prefixLen += routePath.length() - 1;

    }

    return prefixLen != 0 ? path.substring(prefixLen) : path;

  }