CODEWITHSUNDEEP
javaterminal
Giannis
Giannis

Reputation: 5526

Running java class from terminal

This question has been asked before but I still cannot figure whats wrong for some reason. I got a class named NewClass in package syntaxtest in file src. From src path I type :

javac src/syntaxtest/NewClass.java

and the class is compiled and I can see NewClass.class in syntaxtest folder. Now from that same path or even the same folder with NewClass.class, I can't figure out how to run the class from terminal. I have made many different attempts but ether I get

ClassDefNotFound or ClassDefNotFound (wrong name : syntaxtest/NewClass)

Upvotes: 3

Views: 30461

Answers (4)

Brian Figueroa
Brian Figueroa

Reputation: 29

You need to package the class as a runnable JAR. This can be accomplished from your IDE. Then, just use the java -jar jarname.jar command to run your jar from the terminal without issues.

Upvotes: 0

David Azar
David Azar

Reputation: 361

I had a similar problem. I wanted to organize my project using a src and bin folders directly from the Mac finder and use Emacs or some other text editor. I just didn't like eclipse.

You can't execute the classes from another folder, but you can do is compile from another folder into the one you are going to execute.

For example (assuming there is no package), move to the bin folder and run:

$ javac ../src/name.java -d ../bin/

(That compiles from the src folder and outs the .class file directly on bin)

Upvotes: 0

Renato
Renato

Reputation: 13690

I've made the following test:

  • Created a java file in home/test/blah/TestClass.java

    package blah;

    public class TestClass { public static void main(String[] args) { System.out.println("Hello World!"); } }

  • Went to directory home/test/

  • Compiled the file by typing:
javac blah/TestClass.java
  • Got the file compiled ok.
  • Ran it by typing:
java blah.TestClass
  • Got the message "Hello World!" as expected: program runs ok.
  • Went to directory home/
  • Tried to run by typing:

java test/blah.TestClass

  • ... and many other combinations of slashes and dots..... nothing worked.... keep getting the same Exception as you:
java.lang.NoClassDefFoundError

So it seems to me that to run a Java class using the command 'java' you really must be in the application's root folder.

Upvotes: 2

maerics
maerics

Reputation: 156444

Try "java -cp src syntaxtest.NewClass".

That is, if you have a folder "src" which contains the subfolder (package) "syntaxtest" and the class "NewClass" is in "package syntaxtest", then the above command will work.

$ ls src/syntaxtest
NewClass.java
$ cat src/syntaxtest/NewClass.java
package syntaxtest;
public class NewClass {
  public static void main(String args[]) {
    System.out.println("Hello, World!");
  }
}
$ javac src/syntaxtest/NewClass.java
$ java -cp src syntaxtest.NewClass
Hello, World!

Upvotes: 8

Related Questions