storm-starter with intellij idea,maven project could not find class - maven

Question

I'm beginner of storm and intellij idea,when I import storm-starter(apache-storm-0.9.5.zip) to intellij idea(14 CE OS),everything is OK,but when I run the "ExclamationTopology" ,a problem appears as follow:
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
this interface is from storm-core,but this maven managed jar is in my library
Why does this happened..?

Answer 1

Strom already has required jar on the server side. So, if look into the pom.xml you find something similar to:
https://github.com/apache/storm/blob/master/examples/storm-starter/pom.xml
<dependency>
<groupId>org.apache.storm</groupId>
<artifactId>storm-core</artifactId>
<version>${project.version}</version>
<!-- keep storm out of the jar-with-dependencies -->
<scope>provided</scope>
</dependency>
The provided scope is only available on the compilation and test classpath. Because of it your project compiles, but then fails in the runtime with exception : java.lang.NoClassDefFoundError.
Please, comment the scope line in your pom.xml and update maven dependencies to solve this problem. It should looks like:
<dependency>
<groupId>org.apache.storm</groupId>
<artifactId>storm-core</artifactId>
<version>${project.version}</version>
<!-- keep storm out of the jar-with-dependencies -->
<!-- <scope>provided</scope> -->
</dependency>