Okay, the type parameters with the variances need to be after the method
name, like this:
private def createNewConsumer[K <: java.util.ArrayList[Byte],V <:
java.util.ArrayList[Byte]](): KafkaConsumer[K,V] = {...}
Dean Wampler, Ph.D.
Author: Programming Scala, 2nd Edition
<http://shop.oreilly.com/product/0636920033073.do> (O'Reilly)
Lightbend <http://lightbend.com>
@deanwampler <http://twitter.com/deanwampler>
http://polyglotprogramming.com
On Wed, Aug 31, 2016 at 8:08 AM, Martin Gainty <[email protected]> wrote:
> supposedly gmail wont strip \n so we'll try again with non-html mail
> composer
>
> noob with Scala so Im looking for an experienced answer
>
> ConsumerGroupCommand.scala
>
> //private def createNewConsumer(): KafkaConsumer[String, String] = {
> //private def createNewConsumer(): KafkaConsumer[K extends
> // java.util.ArrayList[Byte],V extends java.util.ArrayList[Byte]] = {
>
> private def createNewConsumer(): KafkaConsumer[K <:
> java.util.ArrayList[Byte],V <: java.util.ArrayList[Byte]] = {
>
> val properties = new java.util.Properties()
>
> val deserializer = (new StringDeserializer).getClass.getName
>
> val brokerUrl = opts.options.valueOf(opts.bootstrapServerOpt)
>
> properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, brokerUrl)
>
> properties.put(ConsumerConfig.GROUP_ID_CONFIG,opts.options.
> valueOf(opts.groupOpt))
>
> properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false")
>
> properties.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "30000")
>
> properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
> deserializer)
>
> properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
> deserializer)
>
> if (opts.options.has(opts.commandConfigOpt))
> properties.putAll(Utils.loadProps(opts.options.
> valueOf(opts.commandConfigOpt)))
>
> new KafkaConsumer(properties).asInstanceOf[KafkaConsumer[K,V]]
> }
>
> scala-compiler displays:
> [ERROR] \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:309:
> error: ']' expected but '<:' found.
>
> [ERROR] private def createNewConsumer(): KafkaConsumer[? <:
> java.util.ArrayList[Byte],? <: java.util.ArrayList[Byte]] = {
> [ERROR] ^
>
> [ERROR]
> \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:309:
> error: '=' expected but ',' found.
>
> [ERROR] private def createNewConsumer(): KafkaConsumer[? <:
> java.util.ArrayList[Byte],? <: java.util.ArrayList[Byte]] = {
> [ERROR]
> ^
>
> [ERROR]
> \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:322:
> error: illegal start of simple expression
>
> i need 2 datatype parameter types extending java.util.ArrayList<Byte>
> in regular java this would be:
>
> public KafkaConsumer<K extends java.util.ArrayList<Byte>,V extends
> java.util.ArrayList<Byte>> createNewConsumer() { ....}
>
> this works in java but
> how do I setup a function or class declaration K, V whose parameter
> datatype extends java.util.ArrayList<Byte> ?
>
> Martin
>
> >>
> >> From: [email protected]
> >> To: [email protected]; [email protected]
> >> Subject: RE: handling generics in Kafka Scala
> >> Date: Tue, 30 Aug 2016 23:00:29 -0400
> >>
> >>
> >>
> >>
> >> noob with Scala so Im looking for an experienced answer
> >> ConsumerGroupCommand.scala
> >> //private def createNewConsumer(): KafkaConsumer[String, String] =
> >> {//private def createNewConsumer(): KafkaConsumer[K extends
> >> java.util.ArrayList[Byte],V extends java.util.ArrayList[Byte]] = {
> >> private def createNewConsumer(): KafkaConsumer[K <:
> >> java.util.ArrayList[Byte],V <: java.util.ArrayList[Byte]] = { val
> >> properties = new java.util.Properties() val deserializer = (new
> >> StringDeserializer).getClass.getName val brokerUrl =
> >> opts.options.valueOf(opts.bootstrapServerOpt)
> >> properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, brokerUrl)
> >> properties.put(ConsumerConfig.GROUP_ID_CONFIG,
> >> opts.options.valueOf(opts.groupOpt))
> >> properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false")
> >> properties.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "30000")
> >> properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
> >> deserializer)
> >> properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
> >> deserializer) if (opts.options.has(opts.commandConfigOpt))
> >> properties.putAll(Utils.loadProps(opts.options.
> valueOf(opts.commandConfigOpt)))
> >> new KafkaConsumer(properties).asInstanceOf[KafkaConsumer[K,V]]
> }
> >> scala-compiler displays:
> >> [ERROR]
> >> \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:309:
> >> error: ']' expected but '<:' found.[ERROR] private def
> >> createNewConsumer(): KafkaConsumer[? <: java.util.ArrayList[Byte],? <:
> >> java.util.ArrayList[Byte]] = {[ERROR]
> >> ^[ERROR]
> >> \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:309:
> >> error: '=' expected but ',' found.[ERROR] private def
> >> createNewConsumer(): KafkaConsumer[? <: java.util.ArrayList[Byte],? <:
> >> java.util.ArrayList[Byte]] = {[ERROR]
> >> ^[ERROR]
> >> \kafka\kafka-trunk\core\src\main\scala\kafka\admin\
> ConsumerGroupCommand.scala:322:
> >> error: illegal start of simple expression
> >> i want 2 datatype parameter types extending java.util.ArrayList<Byte> in
> >> regular java this would be:
> >> public KafkaConsumer<K extends java.util.ArrayList<Byte>,V extends
> >> java.util.ArrayList<Byte>> createNewConsumer() {}
> >> how do I setup a function or class declaration K, V whose parameter
> >> datatype
> >> extends java.util.ArrayList<Byte> ?
> >> Martin
> >> ______________________________________________
> >>
> >>
> >>
> >>> From: [email protected]
> >>> Date: Wed, 17 Aug 2016 18:06:38 -0600
> >>> Subject: Re: DLL Hell
> >>> To: [email protected]
> >>>
> >>> Hi Martin,
> >>>
> >>> I'm sorry, this is way outside my Kafka knowledge. I'm just a new
> >>> Kafka user who wanted to help with your Windows questions because I
> >>> had just faced the same hurdle. :-) Wish I could help, but I wouldn't
> >>> know where to start with this.
> >>>
> >>> Mathieu
> >>>
> >>>
> >>> On Wed, Aug 17, 2016 at 6:00 PM, Martin Gainty <[email protected]>
> >>> wrote:
> >>> > Hi Matthieu
> >>> > Many Thanks for attaching the binary
> >>> >
> >>> > running scala->java generator plugin I see:
> >>> >
> >>> > [ERROR]
> >>> > C:\Maven-plugin\kafka\kafka-trunk\core\src\main\scala\
> kafka\admin\AdminUtils.scala:639:
> >>> > error: type PartitionMetadata is not a member of object
> >>> > org.apache.kafka.common.requests.MetadataResponse
> >>> >
> >>> > yet when I look at
> >>> > org.apache.kafka.common.requests.MetadataResponse.java I
> >>> > see inner class
> >>> >
> >>> > public static class PartitionMetadata {
> >>> >
> >>> > inner static java classes are not visible to the converter for some
> >>> > reason
> >>> > the workaround seems to be birth inner static classes (e.g.
> >>> > PartitionMetadata)
> >>> > treating inner class as standalone works
> >>> >
> >>> > Advice?
> >>> > Martin
> >>> > ______________________________________________
> >>> >
> >>> >
> >>> >
> >>> >
> >>> > ________________________________
> >>> > From: [email protected]
> >>> > Date: Tue, 16 Aug 2016 08:04:52 -0600
> >>> > Subject: Re: DLL Hell
> >>> > To: [email protected]
> >>> >
> >>> >
> >>> > Hey Martin,
> >>> >
> >>> > Attached is the native .dll that I was able to build for rocksdb. If
> >>> > you
> >>> > unzip this, and include the contained .dll into your
> >>> > rocksdbjni-4.8.0.jar at
> >>> > the root, it should be possible to use Kafka Streams in Windows. But
> >>> > this
> >>> > is just a minimal debug build; wouldn't be appropriate for production
> >>> > use.
> >>> > Might save you some time if you're just trying to get a dev
> >>> > environment
> >>> > working though.
> >>> >
> >>> > Mathieu
> >>> >
> >>> >
> >>> > On Tue, Aug 16, 2016 at 7:40 AM, Martin Gainty <[email protected]>
> >>> > wrote:
> >>> >
> >>> >
> >>> >
> >>> >
> >>> >> From: [email protected]
> >>> >> Date: Tue, 16 Aug 2016 06:57:16 -0600
> >>> >> Subject: Re: DLL Hell
> >>> >> To: [email protected]
> >>> >>
> >>> >> Hey Martin,
> >>> >>
> >>> >> I had to modify the -G argument to that command to include the
> visual
> >>> >> studio year. If you run "cmake /?", it will output all the
> available
> >>> >> generators. My cmake looked like:
> >>> >>
> >>> >> cmake -G "Visual Studio 12 2013 Win64" -DJNI=1 ..
> >>> >>
> >>> >> I think this is probably a change in cmake since the rocksdb doc was
> >>> >> written (
> >>> >>
> >>> >> https://cmake.org/cmake/help/v3.0/generator/Visual%
> 20Studio%2012%202013.html
> >>> >> ).
> >>> >> MG>same "informative error"
> >>> >>C:\cygwin64\bin\cmake -G "Visual Studio 12 2013 Win64" -DJNI=1
> >>> > CMake Error: Could not create named generator Visual Studio 12 2013
> >>> > Win64
> >>> > Generators Unix Makefiles = Generates standard UNIX
> >>> > makefiles. Ninja = Generates build.ninja
> >>> > files.
> >>> > CodeBlocks - Ninja = Generates CodeBlocks project files.
> >>> > CodeBlocks - Unix Makefiles = Generates CodeBlocks project files.
> >>> > CodeLite
> >>> > - Ninja = Generates CodeLite project files. CodeLite -
> >>> > Unix
> >>> > Makefiles = Generates CodeLite project files. Eclipse CDT4 -
> Ninja
> >>> > = Generates Eclipse CDT 4.0 project files. Eclipse CDT4 - Unix
> >>> > Makefiles=
> >>> > Generates Eclipse CDT 4.0 project files. KDevelop3
> >>> > =
> >>> > Generates KDevelop 3 project files. KDevelop3 - Unix Makefiles =
> >>> > Generates KDevelop 3 project files. Kate - Ninja =
> >>> > Generates Kate project files. Kate - Unix Makefiles =
> >>> > Generates
> >>> > Kate
> >>> > project files. Sublime Text 2 - Ninja = Generates Sublime Text
> >>> > 2
> >>> > project files. Sublime Text 2 - Unix Makefiles
> >>> > = Generates Sublime Text 2 project files.
> >>> > MG>I am thinking if I want to automate this native build..I could
> more
> >>> > easily create binary thru maven-nar-plugin ?
> >>> > MG>as I do not have any MS VS or DotNet installed..maybe I need to
> >>> > install
> >>> > many gigs of MS specific VS?
> >>> > MG>Please advise
> >>> >> Mathieu
> >>> >>
> >>> >>
> >>> >> On Tue, Aug 16, 2016 at 5:03 AM, Martin Gainty <[email protected]
> >
> >>> >> wrote:
> >>> >>
> >>> >> > havent used cmake in over 10 years so Im a bit lost..
> >>> >> > cmake -G "Visual Studio 12 Win64" -DGFLAGS=1 -DSNAPPY=1
> >>> >> > -DJEMALLOC=1
> >>> >> > -DJNI=1
> >>> >> > CMake Error: Could not create named generator Visual Studio 12
> >>> >> > Win64
> >>> >> > ?Please advise
> >>> >> > Martin
> >>> >> > ______________________________________________
> >>> >> >
> >>> >> >
> >>> >> >
> >>> >> > > From: [email protected]
> >>> >> > > Date: Mon, 15 Aug 2016 13:43:47 -0600
> >>> >> > > Subject: Re: DLL Hell
> >>> >> > > To: [email protected]
> >>> >> > >
> >>> >> > > Hi Martin,
> >>> >> > >
> >>> >> > > rocksdb does not currently distribute a Windows-compatible build
> >>> >> > > of
> >>> >> > > their
> >>> >> > > rocksdbjni library. I recently wrote up some instructions on
> how
> >>> >> > > to
> >>> >> > > produce a local build, which you can find here:
> >>> >> > > http://mail-archives.apache.org/mod_mbox/kafka-users/
> >>> >> > 201608.mbox/%3CCAHoiPjweo-xSj3TiodcDVf4wNnnJ8u6PcwWDPF7L
> >>> >> > T5ps%2BxQ3eA%40mail.gmail.com%3E
> >>> >> > >
> >>> >> > > I'd also suggest tracking this issue in GitHub, which is likely
> >>> >> > > to
> >>> >> > > be
> >>> >> > > updated if this ever changes: https://github.com/facebook/
> >>> >> > rocksdb/issues/703
> >>> >> > >
> >>> >> > > Mathieu
> >>> >> > >
> >>> >> > >
> >>> >> > > On Mon, Aug 15, 2016 at 1:34 PM, Martin Gainty
> >>> >> > > <[email protected]>
> >>> >> > wrote:
> >>> >> > >
> >>> >> > > > kafka-trunk\streams>gradle buildCaused by:
> >>> >> > > > java.lang.RuntimeException:
> >>> >> > > > librocksdbjni-win64.dll was not found inside JAR. at
> >>> >> > org.rocksdb.
> >>> >> > > > NativeLibraryLoader.loadLibraryFromJarToTemp(
> >>> >> > NativeLibraryLoader.java:106)
> >>> >> > > > at org.rocksdb.NativeLibraryLoader.loadLibraryFromJar(
> >>> >> > NativeLibraryLoader.java:78)
> >>> >> > > > at org.rocksdb.NativeLibraryLoader.loadLibrary(
> >>> >> > NativeLibraryLoader.java:56)
> >>> >> > > > at org.rocksdb.RocksDB.loadLibrary(RocksDB.java:47) at
> >>> >> > > > org.rocksdb.RocksDB.<clinit>(RocksDB.java:23)
> >>> >> > > > any idea where I can locale librocksdbjni-win64.dll ?
> >>> >> > > > /thanks/
> >>> >> > > > Martin
> >>> >> > > > ______________________________________________
> >>> >> > > >
> >>> >> > > >
> >>> >> >
> >>> >> >
> >>> >
> >>> >
> >>> >
> >>
> >
>
