NoClassDefFoundError uses Scala classes from Java

I don't have Scala experience, so this problem may be basic According to the "person" example in this tutorial, I am using the scala class in Java: http://www.codecommit.com/blog/java/interop-between-java-and-scala

I create two source files, a Scala and a Java, as shown below

Person. scala：

class Person {
  def getName() = "Daniel Spiewak"
}

Test. java：

public class Test {
  public static void main(String[] args) {
    Person p = new Person();
    p.getName();
  }
}

I can compile (with a warning I don't understand), but when I try to run the program, I get a classnotfoundexception

$scalac Person.scala
$javac Test.java
./Person.class: warning: Cannot find annotation method 'bytes()' in type 'ScalaSignature': class file for scala.reflect.ScalaSignature not found
1 warning
$java Test
Exception in thread "main" java.lang.NoClassDefFoundError: scala/ScalaObject
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:787)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.urlclassloader.defineClass(urlclassloader.java:447)
        at java.net.urlclassloader.access$100(urlclassloader.java:71)
        at java.net.urlclassloader$1.run(urlclassloader.java:361)
        at java.net.urlclassloader$1.run(urlclassloader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.urlclassloader.findClass(urlclassloader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        at Test.main(Test.java:3)
Caused by: java.lang.ClassNotFoundException: scala.ScalaObject
        at java.net.urlclassloader$1.run(urlclassloader.java:366)
        at java.net.urlclassloader$1.run(urlclassloader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.urlclassloader.findClass(urlclassloader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        ... 13 more

Any idea what am I doing wrong?

Solution

You need to include the scala runtime library to use Scala classes This is the cause of compiler warnings and errors at run time

Try this

java -cp .:scala-library.jar Test

The name of the jar file may be different, but the point is to add it to your classpath