playframework:启动时出现NullpointerException

Question

我正在使用Play 1.2.7,不知怎的,我发现我的项目变得很奇怪,当我启动应用程序并访问任何有效的URL时,它显示NullPointerException:

Oops: NullPointerException
An unexpected error occured caused by exception NullPointerException: null

play.exceptions.UnexpectedException: Unexpected Error
    at play.Play.start(Play.java:563)
    at play.Play.detectChanges(Play.java:637)
    at play.Invoker$Invocation.init(Invoker.java:198)
    at Invocation.HTTP Request(Play!)
Caused by: java.lang.NullPointerException
    at play.classloading.ApplicationCompiler$2.acceptResult(ApplicationCompiler.java:266)
    at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:478)
    at play.classloading.ApplicationCompiler.compile(ApplicationCompiler.java:282)
    at play.classloading.ApplicationClassloader.getAllClasses(ApplicationClassloader.java:426)
    at play.Play.start(Play.java:523)
    ... 3 more

然后我尝试刷新页面,2或3次后,它变得正常.这里发生了什么？

Answer 1

play不支持一个类中的以下格式

公共类A {

------

}

B级{

-

}

所以制作两个不同的类,而不是将它们放在单个类中或使用嵌套类.