具有intellij想法的风暴启动者,maven项目找不到类

Question

我是暴风雨和intellij想法的初学者,当我将风暴启动器(apache-storm-0.9.5.zip)导入intellij idea(14 CE OS)时,一切都还可以,但是当我运行"ExclamationTopology"时,问题如下:

Exception in thread "main" java.lang.NoClassDefFoundError: backtype/storm/topology/IRichSpout
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:122)
Caused by: java.lang.ClassNotFoundException: backtype.storm.topology.IRichSpout
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 3 more

Process finished with exit code 1

这个界面来自storm-core,但是这个maven托管的jar在我的库中为什么会发生这种情况..？

Answer 1

Strom已经在服务器端需要jar.因此,如果查看pom.xml,您会发现类似于以下内容的内容:https: //github.com/apache/storm/blob/master/examples/storm-starter/pom.xml

<dependency>
  <groupId>org.apache.storm</groupId>
  <artifactId>storm-core</artifactId>
  <version>${project.version}</version>
  <!-- keep storm out of the jar-with-dependencies -->
  <scope>provided</scope>
</dependency>

提供的范围仅适用于编译和测试类路径.因为它你的项目编译,但然后在运行时失败,例外:java.lang.NoClassDefFoundError.

请注意pom.xml中的范围行并更新maven依赖项以解决此问题.它应该看起来像:

<dependency>
  <groupId>org.apache.storm</groupId>
  <artifactId>storm-core</artifactId>
  <version>${project.version}</version>
  <!-- keep storm out of the jar-with-dependencies -->
  <!-- <scope>provided</scope> -->
</dependency>