使用mvn devserver的Google App Engine Java失败：缺少“guestbook / target / guestbook-1.0-SNAPSHOT”

我正在尝试使用Java在Google App Engine上进行简单的教程 ，但是当我尝试运行mvn appengine:devserver命令时，我得到了这个奇怪的丢失目录错误：

 [INFO] guestbook ......................................... FAILURE [ 0.228 s] [INFO] guestbook-war ..................................... SKIPPED [INFO] guestbook-ear ..................................... SKIPPED [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 0.446 s [INFO] Finished at: 2014-05-06T12:03:51-08:00 [INFO] Final Memory: 9M/176M [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal com.google.appengine:appengine-maven-plugin:1.9.4:devserver (default-cli) on project guestbook: The application directory does not exist : /Users/davidt/GoogleAppEngineProjects/guestbook/target/guestbook-1.0-SNAPSHOT -> [Help 1] [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/MojoExecutionException 

到底是怎么回事？ 我什么时候应该创建该快照？

注意：我不确定这是否重要，但我一直在同一文件夹下多次删除并重新创建项目。

Answer 1

你必须在guestbook-ear文件夹中运行mvn appengine:devserver 。 我在顶级运行它。