Question

我有一个我正在研究的java项目，直到几天前才开始工作。我不确定我对我的Eclipse设置做了什么来软管它但现在当我尝试运行一些访问google finance api的代码时，我得到了一个java.lang.ClassNotFoundException。我已经构建了一个小型测试应用程序，它自己使用google finance api，这似乎有效。所以，我认为这是一个项目特定的问题。任何帮助将不胜感激。这是堆栈跟踪：

ptolemy.kernel.util.IllegalActionException:   in .RandomSearch.manager
Because:
com/google/common/collect/Maps
 at ptolemy.actor.Manager.execute(Manager.java:472)
 at ptolemy.actor.Manager.run(Manager.java:1119)
 at ptolemy.actor.Manager$3.run(Manager.java:1160)
Caused by: java.lang.NoClassDefFoundError: com/google/common/collect/Maps
 at com.google.gdata.wireformats.AltRegistry.<init>(AltRegistry.java:118)
 at com.google.gdata.wireformats.AltRegistry.<init>(AltRegistry.java:100)
 at com.google.gdata.client.Service.<clinit>(Service.java:546)
 at AtomicBroadcast.GoogleFinance.GooglePortfolioReader.fire(GooglePortfolioReader.java:108)
 at ptolemy.domains.de.kernel.DEDirector.fire(DEDirector.java:568)
 at ptolemy.actor.CompositeActor.fire(CompositeActor.java:458)
 at ptolemy.actor.Manager.iterate(Manager.java:714)
 at ptolemy.actor.Manager.execute(Manager.java:349)
 ... 2 more
Caused by: java.lang.ClassNotFoundException: com.google.common.collect.Maps
 at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:319)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:264)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:332)
 ... 10 more
Caused by: java.lang.NoClassDefFoundError: com/google/common/collect/Maps
 at com.google.gdata.wireformats.AltRegistry.<init>(AltRegistry.java:118)
 at com.google.gdata.wireformats.AltRegistry.<init>(AltRegistry.java:100)
 at com.google.gdata.client.Service.<clinit>(Service.java:546)
 at AtomicBroadcast.GoogleFinance.GooglePortfolioReader.fire(GooglePortfolioReader.java:108)
 at ptolemy.domains.de.kernel.DEDirector.fire(DEDirector.java:568)
 at ptolemy.actor.CompositeActor.fire(CompositeActor.java:458)
 at ptolemy.actor.Manager.iterate(Manager.java:714)
 at ptolemy.actor.Manager.execute(Manager.java:349)
 at ptolemy.actor.Manager.run(Manager.java:1119)
 at ptolemy.actor.Manager$3.run(Manager.java:1160)
Caused by: java.lang.ClassNotFoundException: com.google.common.collect.Maps
 at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:319)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:264)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:332)
 ... 10 more

Answer 1

您的项目类路径似乎缺少google-collect-1.0-rc1.jar

你显然在你的硬盘上有它，只需编辑项目类路径并将其添加到那里（或确保它由Maven /如果你使用它们添加）。

Answer 2

您必须了解两个类似错误消息之间的区别。我建议你阅读Sanjiv Jivan的精彩文章“ClassNotFoundException和NoClassDefFoundError之间的区别”。 http://www.jroller.com/sjivan/entry/difference_between_classnotfoundexception_and_noclassdeffounderror

Answer 3

我遇到了类似的问题。我没有在gdata api中找到google-collect-1.0-rc1.jar。但是thread解决了我的问题：

将guava.xxx.jar添加到您的项目中。 Guava是旧版Google Collections Library的完全兼容的超集。
您可以在gdata-samples / java / deps / guava.xxxx.jar中找到guava-xxxx.jar。或者从here下载。

Google推荐Guava而不是google-collect-1.0.jar。 see here

抛出java.lang.ClassNotFoundException

3 个答案: