我要做的是使用google appengine插件为maven部署/更新我的网络应用程序。
因此我在pom.xml文件中添加了插件：
<project>
<!-- .. -->
<profiles>
<profile>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.version}</version>
<configuration>
<enableJarClasses>false</enableJarClasses>
<version>${app.version}</version>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>gcloud-maven-plugin</artifactId>
<version>${gcloud.plugin.version}</version>
<configuration>
<set_default>true</set_default>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.version}</version>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>
我还添加了pluginGroup：
<pluginGroups>
<!-- pluginGroup
| Specifies a further group identifier to use for plugin lookup.
<pluginGroup>com.your.plugins</pluginGroup>
-->
<pluginGroup>com.google.appengine</pluginGroup>
</pluginGroups>
但是，如果我致电mvn appengine:update我正在接收
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] mz-parent
[INFO] mz-web-shared
[INFO] mz-data-model
[INFO] mz-web-client
[INFO] mz-mobile-rest-shared
[INFO] mz-mobile-rest-api
[INFO] mz-web-server
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building mz-parent 0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> appengine-maven-plugin:1.9.32:update (default-cli) > package @ mz-parent >>>
[INFO]
[INFO] --- maven-enforcer-plugin:1.2:enforce (enforce-maven) @ mz-parent ---
[INFO]
[INFO] <<< appengine-maven-plugin:1.9.32:update (default-cli) < package @ mz-parent <<<
[INFO]
[INFO] --- appengine-maven-plugin:1.9.32:update (default-cli) @ mz-parent ---
[INFO]
[INFO] Google App Engine Java SDK - Updating Application
[INFO]
[INFO] Retrieving Google App Engine Java SDK from Maven
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] mz-parent .................................... FAILURE [ 0.390 s]
[INFO] mz-web-shared ................................ SKIPPED
[INFO] mz-data-model ................................ SKIPPED
[INFO] mz-web-client ................................ SKIPPED
[INFO] mz-mobile-rest-shared ........................ SKIPPED
[INFO] mz-mobile-rest-api ........................... SKIPPED
[INFO] mz-web-server ................................ SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.460 s
[INFO] Finished at: 2016-03-18T00:33:58+01:00
[INFO] Final Memory: 16M/226M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.google.appengine:appengine-maven-plugin:1.9.32:update (default-cli) on project mz-parent: Execution default-cli of goal com.google.appengine:appengine-maven-plugin:1.9.32:update failed. NoSuchElementException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal com.google.appengine:appengine-maven-plugin:1.9.32:update (default-cli) on project mz-parent: Execution default-cli of goal com.google.appengine:appengine-maven-plugin:1.9.32:update failed.
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:224)
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:862)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
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.plugin.PluginExecutionException: Execution default-cli of goal com.google.appengine:appengine-maven-plugin:1.9.32:update failed.
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:145)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
... 20 more
Caused by: java.util.NoSuchElementException
at com.google.common.collect.AbstractIterator.next(AbstractIterator.java:154)
at com.google.common.collect.Iterators.find(Iterators.java:717)
at com.google.common.collect.Iterables.find(Iterables.java:646)
at com.google.appengine.SdkResolver.getSdk(SdkResolver.java:50)
at com.google.appengine.appcfg.AbstractAppCfgMojo.resolveAndSetSdkRoot(AbstractAppCfgMojo.java:393)
at com.google.appengine.appcfg.Update.execute(Update.java:26)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
... 21 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/PluginExecutionException
问题：如何解决此问题？
答案 0 :(得分：4)
在这种情况下，你有一个多模块Maven项目，你试图在整个构建中执行appengine:update目标，这可能是不可能的，因为父/聚合器pom（构建失败的地方） ）不会提供目标期望的文件夹结构，因此会导致错误。
事实上，您不想在父级，共享或模型模块等上执行appengine:update。
您应该通过标准
构建整个项目mvn clean install
然后只执行相关的war / ear模块appengine:update（我想你的情况为mz-web-server），也就是你有效想要更新到GAE的模块。
cd mz-web-server <-- move to the concerned module
mvn appengine:update
如果您提到的配置文件在聚合器/父pom中定义并在多模块构建期间激活，则从根目录运行appengine:update将使用已定义的配置并尝试执行update目标在每个模块上，这是你不想要的东西（你实际上不能，合理地给出错误）。
如果您希望继续从根运行appengine:update并仅在相关模块上执行它，那么您应该编辑上面的pluginManagement配置：
pluginManagement插件声明（groupId，artifactId，version）mz-web-server模块）appengin-maven-plugin部分删除plugins声明并将其移至相关模块（实际上，配置已移至上方）。因此，插件将被声明为由多模块构建（通过pluginManagement）管理，但未在每个模块中有效使用（通过plugins），然后仅声明和使用在相关模块中。
此外，由于您在默认构建期间未定义插件的任何execution，因此您甚至不需要我相信的配置文件。您定义的配置将仅由显式命令行调用使用，而不是其他任何内容。
基本上，您可以在聚合器/父pom中使用以下内容：
<project>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.version}</version>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>gcloud-maven-plugin</artifactId>
<version>${gcloud.plugin.version}</version>
</plugin>
</plugins>
</pluginManagement>
</build>
<profiles>
<profile>
<!-- do you really need it? :) -->
</profile>
</profiles>
</project>
然后，在您的mz-web-server模块中，以下内容：
<project>
<build>
<plugins>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<!-- you don't need to re-define the version here -->
<!-- version is taken from pluginManagement from the parent -->
<configuration>
<enableJarClasses>false</enableJarClasses>
<version>${app.version}</version>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>gcloud-maven-plugin</artifactId>
<!-- again, no version here -->
<configuration>
<set_default>true</set_default>
</configuration>
</plugin>
</plugins>
</build>
</project>
请注意pluginManagement部分中plugins和build的不同用法。如需进一步阅读，请查看this SO post。
答案 1 :(得分：0)
以下是我的一个GAE项目中的pom.xml工作示例：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<groupId>com.gae.mvn.demo</groupId>
<artifactId>gae-maven-demo</artifactId>
<properties>
<app.id>your-app-id</app.id>
<app.version>1</app.version>
<appengine.version>1.9.32</appengine.version>
<gcloud.plugin.version>2.0.9.74.v20150814</gcloud.plugin.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
<spring.version>4.2.5.RELEASE</spring.version>
</properties>
<prerequisites>
<maven>3.1.0</maven>
</prerequisites>
<dependencies>
<!-- Compile/runtime dependencies -->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${appengine.version}</version>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-endpoints</artifactId>
<version>${appengine.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<!-- for hot reload of the web application -->
<outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>versions-maven-plugin</artifactId>
<version>2.1</version>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>display-dependency-updates</goal>
<goal>display-plugin-updates</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>3.1</version>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.4</version>
<configuration>
<archiveClasses>true</archiveClasses>
<webResources>
<resource>
<directory>${basedir}/src/main/webapp/WEB-INF</directory>
<filtering>true</filtering>
<targetPath>WEB-INF</targetPath>
</resource>
</webResources>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.version}</version>
<configuration>
<enableJarClasses>false</enableJarClasses>
<version>${app.version}</version>
</configuration>
</executions>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>gcloud-maven-plugin</artifactId>
<version>${gcloud.plugin.version}</version>
<configuration>
<set_default>true</set_default>
</configuration>
</plugin>
</plugins>
</build>
</project>
希望这有帮助！