如何使Netty示例工作

Question

我试图下载Netty源代码并运行包含的示例。

我安装的jdk版本是1.8.0_65。

我尝试用maven( ...\netty-4.1\example)将示例(示例文件夹mvn eclipse:eclipse)转换为eclipse项目。

但得到的构建错误如下所示。

[INFO]
[INFO] >>> maven-eclipse-plugin:2.10:eclipse (default-cli) > generate-resources @ netty-example >>>
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.558 s
[INFO] Finished at: 2016-02-04T13:40:13+08:00
[INFO] Final Memory: 11M/28M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project netty-example: Could not resolve dependencies for project io.netty:netty-example:jar:4.1.0.CR2-SNAPSHOT: Failure to fi
nd io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be r
eattempted until the update interval of central has elapsed or updates are forced -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal on project netty-example: Could not resolve dependencies for project io.netty:net
ty-example:jar:4.1.0.CR2-SNAPSHOT: Failure to find io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo.maven.apache.org/maven2 was cached i
n the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced
        at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.getDependencies(LifecycleDependencyResolver.java:221)
        at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.resolveProjectDependencies(LifecycleDependencyResolver.java:127)
        at org.apache.maven.lifecycle.internal.MojoExecutor.ensureDependenciesAreResolved(MojoExecutor.java:245)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:199)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions(MojoExecutor.java:352)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:197)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
        at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.project.DependencyResolutionException: Could not resolve dependencies for project io.netty:netty-example:jar:4.1.0.CR2-SNAPSHOT: Fai
lure to find io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution wil
l not be reattempted until the update interval of central has elapsed or updates are forced
        at org.apache.maven.project.DefaultProjectDependenciesResolver.resolve(DefaultProjectDependenciesResolver.java:211)
        at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.getDependencies(LifecycleDependencyResolver.java:195)
        ... 27 more
Caused by: org.eclipse.aether.resolution.DependencyResolutionException: Failure to find io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo
.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are
forced
        at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveDependencies(DefaultRepositorySystem.java:384)
        at org.apache.maven.project.DefaultProjectDependenciesResolver.resolve(DefaultProjectDependenciesResolver.java:205)
        ... 28 more
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Failure to find io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo.m
aven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are fo
rced
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:444)
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:246)
        at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveDependencies(DefaultRepositorySystem.java:367)
        ... 29 more
Caused by: org.eclipse.aether.transfer.ArtifactNotFoundException: Failure to find io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11 in https://repo.maven
.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced

        at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.newException(DefaultUpdateCheckManager.java:231)
        at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.checkArtifact(DefaultUpdateCheckManager.java:206)
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.gatherDownloads(DefaultArtifactResolver.java:585)
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.performDownloads(DefaultArtifactResolver.java:503)
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:421)
        ... 31 more
[ERROR]
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException

我遵循了信息中提到的线索。我找到了链接到这个解决方案的http://netty.io/wiki/forked-tomcat-native.html#wiki-h3-6。

我想这可能不是为了我的目的而做的工作。(我只想举个例子)。

所以我想知道要下载的任何Netty开发库来启动Netty应用程序开发。或者任何Pom.xml共享链接都可以很容易地包含在示例项目中？谢谢。

Answer 1

这个答案是根据Netty项目上的https://github.com/netty/netty/issues/4836做出的。

要构建Netty项目，您应该结合使用64位操作系统和64 JVM。这是因为Netty项目使用的依赖项中有一个只支持64位。

根据mvn -version的输出，您正在32位JVM上运行。您应该可以从官方java网站下载64位JVM。

升级到64位JVM还具有以下优点：

• 您可以运行内存超过2GB的程序。
• 使用long和double进行计算将更快，因为java可以使用本机处理器。

有关差异，请参见：64位java平台的好处

您不需要自己编译这些示例，您还可以在maven中心按版本排序：http://central.maven.org/maven2/io/netty/netty-example/上找到它们

Answer 2

在查看日志时，似乎找不到to jar。

在本地存储库中缓存了未能在io.netty:netty-tcnative:jar:windows-x86_32:1.1.33.Fork11中找到https://repo.maven.apache.org/maven2，

您能否尝试使用maven从命令行下载这个tc本机jar，如下所示：

mvn org.apache.maven.plugins:maven-dependency-plugin:get -DrepoUrl=http://central.maven.org/maven2/  -DgroupId=io.netty -DartifactId=netty-tcnative -Dversion=1.1.33.Fork11