NullPointerException in HttpHandler when request.host is null

[Kenji Matsuoka]

If the host header is null, HttpHandler fails:

Internal Server Error (500) for request GET /

Oops: NullPointerException
An unexpected error occured caused by exception NullPointerException: null

play.exceptions.UnexpectedException: Unexpected Error
        at play.server.HttpHandler.serve500(HttpHandler.java:334)
        at play.server.HttpHandler.messageReceived(HttpHandler.java:67)
        at org.apache.mina.common.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:743)
        at org.apache.mina.common.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:405)
        at org.apache.mina.common.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:40)
        at org.apache.mina.common.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:823)
        at org.apache.mina.common.IoFilterAdapter.messageReceived(IoFilterAdapter.java:80)
        at org.apache.mina.common.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:405)
        at org.apache.mina.common.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:40)
        at org.apache.mina.common.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:823)
        at org.apache.mina.filter.codec.ProtocolCodecFilter$ProtocolDecoderOutputImpl.flush(ProtocolCodecFilter.java:379)
        at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:173)
        at org.apache.mina.common.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:405)
        at org.apache.mina.common.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:40)
        at org.apache.mina.common.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:823)
        at org.apache.mina.common.DefaultIoFilterChain$HeadFilter.messageReceived(DefaultIoFilterChain.java:607)
        at org.apache.mina.common.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:405)
        at org.apache.mina.common.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:399)
        at org.apache.mina.common.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:434)
        at org.apache.mina.common.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:396)
        at org.apache.mina.common.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:388)
        at org.apache.mina.common.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:43)
        at org.apache.mina.common.AbstractPollingIoProcessor$Worker.run(AbstractPollingIoProcessor.java:706)
        at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
        at play.server.HttpHandler.parseRequest(HttpHandler.java:102)
        at play.server.HttpHandler.messageReceived(HttpHandler.java:53)
        ... 25 more

[Michael Boyd (mic-t-boyd)]

I am also seeing this bug appear in the error log often (like once every 15 minutes, and it is very annoying).

One case where 'host' is missing from the header is if you have cPanel set to monitor Apache for crashes and auto-restart it. The request cPanel makes does not contain 'host'.