I can't run any java program with terminal:
openjdk version "10.0.2" 2018-07-17 OpenJDK Runtime Environment (build
10.0.2+13-Ubuntu-1ubuntu0.18.04.2) OpenJDK 64-Bit Server VM (build 10.0.2+13-Ubuntu-1ubuntu0.18.04.2, mixed mode)
Any ideas?
Asked
Active
Viewed 5,099 times
-2
pomsky
- 68,507
Николай Матев
- 113
-
And where is the command that gave this error? – George Udosen Oct 13 '18 at 11:05
-
Down in screenshot, i use command "java" to run javafile. – Николай Матев Oct 13 '18 at 11:12
-
2Compile first before running, and you're using an IDE so use that to compile and run it. Images of this sort aren't advised copy and paste! – George Udosen Oct 13 '18 at 11:35
-
This has nothing to do with Ubutnu. Learn to use javac, and java. Or just use IDE to run. – Gayan Weerakutti Oct 13 '18 at 12:39
-
I'm using Intellij, but i need to learn some terminal commands, who can help me in the future :) I was reading about java and javac commands, but totally forgot about that packages are not folders :) – Николай Матев Oct 13 '18 at 12:50
-
Possible duplicate of I get no output when I compile Java code from the Terminal – karel Oct 14 '18 at 04:15
1 Answers
1
To compile Java source code (usually with a file ending in .java) you need to enact the Java Compiler, a.k.a. javac. This compiles the source to a bytecode binary file ending in .class.
When running bytecode binaries, you refer to the full classname, not the file. Java will then look for the appropriate .class file relative to the current location, load the appropriate class, and call the function main(). This allows there to be many (even nested) callable starts to a program from the one compiled binary classfile.
Furthermore, Java classes can exist in packages which are organised by directory, and declared at the top of the file, e.g.
package Arrays;
So, once you have compiled your program, you need to be in the folder above the Arrays folder, and then remove the .java from your java command and prefix the classname with 'Arrays.'. e.g.
$ cd /path/to/src
$ java Arrays.Speeds
tudor -Reinstate Monica-
- 7,288
-
-
I missed that your application is in a
package Arrays. I have updated my answer to the correct way to call packaged classes. – tudor -Reinstate Monica- Oct 13 '18 at 11:40 -
Effectively the same as this question: https://stackoverflow.com/questions/19433366/running-java-in-package-from-command-line#19433387 – tudor -Reinstate Monica- Oct 13 '18 at 11:42
-
It's work, thanks. I forgot that Arrays is package and I use it like a folder... – Николай Матев Oct 13 '18 at 11:57