Unable to run Java code with Apache Commons

Question

I've written a program to read in data from a text file and do some simple calculations, then print out those calculations. That part works great.

Afterward, I added in some code to do a t-test, using the TTest class (org.apache.commons.math3.stat.inference.TTest). So, I downloaded commons-math3-3.6.jar from the Apache Commons download page and put the JAR file in the same folder as the rest of my Java code for this program.

I use the following command in Windows to compile, which works fine:

javac -cp ./commons-math3-3.6.jar ./FootballTeam.java ./Main.java

But I can't figure out how to correctly run the program. I've tried this:

java Main

which executes everything up to the t-test perfectly, and then gives the expected error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/math3/stat/inference/TTest at Main.main(Main.java:32) Caused by: java.lang.ClassNotFoundException: org.apache.commons.math3.stat.inference.TTest at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 1 more

I've also tried this:

java -cp commons-math3-3.6.jar Main

which gives me this:

Error: Could not find or load main class Main

I cannot for the life of me figure out how to properly set the classpath here. Can someone provide me some assistance? Thank you!

Answer 1

The Main class cannot be found because the current directory ( . ) is not on your classpath.

To add it, on Windows:

java -cp ".;commons-math3-3.6.jar" Main

On *n?x:

java -cp ".:commons-math3-3.6.jar" Main