title: Error when attempting to run JUnit test runner
body: <p>I am attempting to use JUnit for the first time, but I seem to be having some issues when running my compiled test runner. I am using java from the command-line and running macOS.</p>
  
  <p>I successfully compiled my two jar files and 4 java source files using the following command:</p>
  
  <blockquote>
    <p>javac -classpath junit-4.12.jar:jar2.jar StackLinkedTestRunner.java 2.java 3.java 4.java</p>
  </blockquote>
  
  <p>However, when I execute <code>java StackLinkedTestRunner</code>, I get the following error:</p>
  
  <blockquote>
    <p>Exception in thread "main" java.lang.NoClassDefFoundError:
    org/junit/runner/JUnitCore    at
    StackLinkedTestRunner.main(StackLinkedTestRunner.java:9) Caused by:
    java.lang.ClassNotFoundException: org.junit.runner.JUnitCore  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)     ... 1 more</p>
  </blockquote>
  
  <p>I've googled the error, but I really don't understand any of the returned problems or solutions. I would greatly appreciate it if people could please take the time to explain what I'm doing incorrectly and how I can go about fixing it.</p>