带有 maven 开发服务器的 Google App Engine Java 失败：缺少“guestbook/target/guestbook-1.0-SNAPSHOT”

Question

我正在尝试通过简单的tutorial on Google App Engine with Java，但是当我尝试运行mvn appengine:devserver 命令时，我收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

发生了什么事？我应该什么时候创建那个快照？

注意：我不确定这是否重要，但我一直在同一个文件夹下多次删除和重新创建项目。

Answer 1

您必须在guestbook-ear 文件夹中运行mvn appengine:devserver。我在顶层运行它。