com.google.appengineの 'dependencies.dependency.version'：appengine-api-1.0-sdk：jarは有効なバージョンである必要がありますが、 '$ {appengine.target.version}'です

Question

mavenを使用してプロジェクトを作成しました3.3.9コマンドmvn archetype：generateを使用してエンドポイントのarchtypeを検索し、それを選択して、次にgroupid artifectIdのバージョンを挿入します。その後、Eclipse Neonでこのプロジェクトをインポートします。このプロジェクトappengineを実行しています。下記エラーメッセージ取得しています：

Resolving expression: '${gcloud.plugin.version}': Detected the following recursive expression cycle in 'gcloud.plugin.version': [gcloud.plugin.version] -> [Help 2] 
[ERROR]  Resolving expression: '${gcloud.plugin.version}': Detected the following recursive expression cycle in 'gcloud.plugin.version': [gcloud.plugin.version] -> [Help 2] 
[ERROR]  'dependencies.dependency.version' for com.google.appengine:appengine-api-1.0-sdk:jar must be a valid version but is '${appengine.target.version}'. @ line 34, column 13 
[ERROR]  'dependencies.dependency.version' for com.google.appengine:appengine-endpoints:jar must be a valid version but is '${appengine.target.version}'. @ line 39, column 13 
[ERROR]  'dependencies.dependency.version' for com.google.appengine:appengine-testing:jar must be a valid version but is '${appengine.sdk.version}'. @ line 69, column 13 
[ERROR]  'dependencies.dependency.version' for com.google.appengine:appengine-api-stubs:jar must be a valid version but is '${appengine.sdk.version}'. @ line 75, column 13 
[ERROR]  'build.plugins.plugin.version' for com.google.appengine:appengine-maven-plugin must be a valid version but is '${appengine.sdk.version}'. @ line 122, column 14 
[ERROR]  'build.plugins.plugin.version' for com.google.appengine:gcloud-maven-plugin must be a valid version but is '${gcloud.plugin.version}'. @ line 145, column 14 
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch. 
[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/ProjectBuildingException 
[ERROR] [Help 2] http://cwiki.apache.org/confluence/display/MAVEN/InterpolationCycleException 

を生成pom.xmlファイルは以下のとおりです。私はなぜこのエラーが発生しているのか、どうやって解決するのか分からない。最初のError readingから、私は{{gcloud.plugin.version}}に間違った情報を得ましたが、何が問題なのですか？この問題をどう解決することができますか？

<?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.demo.app</groupId> 
<artifactId>demo-app</artifactId> 

<properties> 
    <app.id>your-app-id</app.id> 
    <app.version>1</app.version> 
    <appengine.version>${appengine.sdk.version}</appengine.version> 
    <gcloud.plugin.version>${gcloud.plugin.version}</gcloud.plugin.version> 
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 
    <maven.compiler.source>1.7</maven.compiler.source> 
    <maven.compiler.target>1.7</maven.compiler.target> 
    <maven.compiler.showDeprecation>true</maven.compiler.showDeprecation> 
    <archiveClasses>true</archiveClasses> 
</properties> 

<prerequisites> 
    <maven>3.3.9</maven> 
</prerequisites> 

<dependencies> 
    <!-- Compile/runtime dependencies --> 
    <dependency> 
     <groupId>com.google.appengine</groupId> 
     <artifactId>appengine-api-1.0-sdk</artifactId> 
     <version>${appengine.target.version}</version> 
    </dependency> 
    <dependency> 
     <groupId>com.google.appengine</groupId> 
     <artifactId>appengine-endpoints</artifactId> 
     <version>${appengine.target.version}</version> 
    </dependency> 
    <dependency> 
     <groupId>javax.servlet</groupId> 
     <artifactId>servlet-api</artifactId> 
     <version>2.5</version> 
     <scope>provided</scope> 
    </dependency> 
    <dependency> 
     <groupId>javax.inject</groupId> 
     <artifactId>javax.inject</artifactId> 
     <version>1</version> 
    </dependency> 

    <!-- Test Dependencies --> 
    <dependency> 
     <groupId>junit</groupId> 
     <artifactId>junit</artifactId> 
     <version>4.12</version> 
     <scope>test</scope> 
    </dependency> 
    <dependency> 
     <groupId>org.mockito</groupId> 
     <artifactId>mockito-all</artifactId> 
     <version>2.0.2-beta</version> 
     <scope>test</scope> 
    </dependency> 
    <dependency> 
     <groupId>com.google.appengine</groupId> 
     <artifactId>appengine-testing</artifactId> 
     <version>${appengine.version}</version> 
     <scope>test</scope> 
    </dependency> 
    <dependency> 
     <groupId>com.google.appengine</groupId> 
     <artifactId>appengine-api-stubs</artifactId> 
     <version>${appengine.version}</version> 
     <scope>test</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> 
      <artifactId>maven-war-plugin</artifactId> 
      <version>2.6</version> 
      <configuration> 
       <webXml>${project.build.directory}/generated-sources/appengine-endpoints/WEB-INF/web.xml</webXml> 
       <webResources> 
        <resource> 
         <!-- this is relative to the pom.xml directory --> 
         <directory>${project.build.directory}/generated-sources/appengine-endpoints</directory> 
         <!-- the list has a default value of ** --> 
         <includes> 
          <include>WEB-INF/*.discovery</include> 
          <include>WEB-INF/*.api</include> 
         </includes> 
        </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> 
       <!-- Comment in the below snippet to bind to all IPs instead of just 
        localhost --> 
       <!-- address>0.0.0.0</address> <port>8080</port --> 
       <!-- Comment in the below snippet to enable local debugging with a remote 
        debugger like those included with Eclipse or IntelliJ --> 
       <!-- jvmFlags> <jvmFlag>-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n</jvmFlag> 
        </jvmFlags --> 
      </configuration> 
      <executions> 
       <execution> 
        <goals> 
         <goal>endpoints_get_discovery_doc</goal> 
        </goals> 
       </execution> 
      </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> 

Answer 1

<properties>でappengine.target.versionとgcloud.plugin.versionプロパティを定義します。あなたは `appengine.target.version`プロパティを定義していないhttps://cloud.google.com/sdk/downloads

<appengine.version>1.9.42</appengine.version> 
     <gcloud.plugin.version>124</gcloud.plugin.version>