How to use classpath in ubuntu terminal for executing java class?

Question

I tried to execute CreateTextFileTest.class file with classpath in the terminal as the following:

java -classpath ..:"/home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17/unit17/creatingtextfile" CreateTextFileTest

My class files in this directory : /home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17/unit17/creatingtextfile .

I have 3 classes in the directory: AccountRecord.class , CreateTextFile.class, and CreateTextFileTest.class

But, when I executed the CreateTextFileTest from the terminal with the code above, an error occured like that:

Exception in thread "main" java.lang.NoClassDefFoundError: CreateTextFileTest (**wrong name**: unit17/creatingtextfile/CreateTextFileTest)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

As far as I understand because CreateTextFileTest.java uses two different classes, executing fails. How to handle this situation? How to run my java project? How to use classpath in this situation? Am I using wrongly?

Stephen Kitt Stephen Kitt · Accepted Answer · 2015-02-12T09:12:25

The error message states that the package name declared in your compiled class doesn't match what the JVM was expecting given your classpath setup. The classpath should point to the directory from which your packages start, not the directory actually containing your .class files. Given your error message I believe that this should work:

java -classpath ..:"/home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17" unit17.creatingtextfile.CreateTextFileTest

Given the duplicate unit17 in your path I get the impression there's something else mixed up here. You'll get a better answer on Stack Overflow...

How to use classpath in ubuntu terminal for executing java class?

1 Answers