在developers.google.com上使用GWT教程获取错误 [英] Getting errors with GWT tutorial on developers.google.com

问题描述

我试图运行此处提供的逐字示例 https：/ /developers.google.com/web-toolkit/doc/latest/tutorial/appengine

这部分内容涉及将gwt项目转换为应用程序引擎项目以及部署它。在我使用ant devmode进行本地测试时，在执行安装程序中的所有步骤后，出现以下错误：
ERROR shell在doStartUpServer方法中失败。

在终端，我得到这些错误。

devmode：

  [ java]无法启动嵌入式HTTP服务器
 [java] java.lang.RuntimeException：无法找到App Engine代理。请使用dev_appserver，KickStart或设置jvm标志：-javaagent：< sdk_root> /lib/agent/appengine-agent.jar
 [java] at com.google.appengine.tools.development.DevAppServerFactory .testAgentIsInstalled（DevAppServerFactory.java:171）
 [java] at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer（DevAppServerFactory.java:142）
 [java] at com.google.appengine .tools.development.DevAppServerFactory.createDevAppServer（DevAppServerFactory.java:78）
 [java] at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer（DevAppServerFactory.java:52）
 [java] com.google.appengine.tools.development.gwt.AppEngineLauncher.start（AppEngineLauncher.java:84）
 [java] at com.google.gwt.dev.DevMode.doStartUpServer（DevMode.java:509）
 [java] at com.google.gwt.dev.DevModeBase.startUp（DevModeBase.java:1068）
 [java] at com.google.gwt.dev.DevModeBase.run（DevMo deBase.java:811）
 [java] at com.google.gwt.dev.DevMode.main（DevMode.java:311）
 [java]引起来自：java.lang.NoClassDefFoundError：com / google / appengine / tools / development / agent / AppEngineDevAgent 
 [java] at com.google.appengine.tools.development.DevAppServerFactory.testAgentIsInstalled（DevAppServerFactory.java:167）
 [java] ... 8更多
 [java]引发：java.lang.ClassNotFoundException：com.google.appengine.tools.development.agent.AppEngineDevAgent 
 [java] at java.net.URLClassLoader $ 1.run（URLClassLoader.java ：202）
 [java] at java.security.AccessController.doPrivileged（Native Method）
 [java] at java.net.URLClassLoader.findClass（URLClassLoader.java:190）
 [java ]在java.lang.ClassLoader.loadClass（ClassLoader.java:306）
 [java] at sun.misc.Launcher $ AppClassLoader.loadClass（Launcher.java:301）
 [java] at java。 lang.ClassLoader.loadClass（ClassLoader.java:247）
 [java] ... 9 more 
  

解决方案

幸运的是，能够解决这个问题。我手动将appengine-agent.jar和appengine-agentimpl.jar复制到WEB-INF / lib目录中。不知何故蚂蚁devmode不能将这些罐子复制到lib文件夹。不知道为什么会出现这种行为。

：）

I was trying to run the verbatim example given here https://developers.google.com/web-toolkit/doc/latest/tutorial/appengine

This part deals with converting a gwt project into app engine project and deploying it. After doing all the steps in the Setup a project heading when I tested locally using ant devmode I get the following error ERROR shell failed in doStartUpServer method.

And in the terminal I get these errors.

devmode:

   [java] Unable to start embedded HTTP server
     [java] java.lang.RuntimeException: Unable to locate the App Engine agent. Please use dev_appserver, KickStart,  or set the jvm flag: "-javaagent:<sdk_root>/lib/agent/appengine-agent.jar"
     [java]     at com.google.appengine.tools.development.DevAppServerFactory.testAgentIsInstalled(DevAppServerFactory.java:171)
     [java]     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:142)
     [java]     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:78)
     [java]     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:52)
     [java]     at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:84)
     [java]     at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
     [java]     at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
     [java]     at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
     [java]     at com.google.gwt.dev.DevMode.main(DevMode.java:311)
     [java] Caused by: java.lang.NoClassDefFoundError: com/google/appengine/tools/development/agent/AppEngineDevAgent
     [java]     at com.google.appengine.tools.development.DevAppServerFactory.testAgentIsInstalled(DevAppServerFactory.java:167)
     [java]     ... 8 more
     [java] Caused by: java.lang.ClassNotFoundException: com.google.appengine.tools.development.agent.AppEngineDevAgent
     [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
     [java]     at java.security.AccessController.doPrivileged(Native Method)
     [java]     at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
     [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
     [java]     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
     [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
     [java]     ... 9 more

解决方案

Fortunately, I was able to solve this problem. I copied appengine-agent.jar and appengine-agentimpl.jar manually into the WEB-INF/lib directory. Somehow ant devmode was not able to copy these jars into the lib folder. Don't know why this behaviour.

:)

这篇关于在developers.google.com上使用GWT教程获取错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！