Develop Reference

IntelliJ: cannot launch a java application using the command line

Let me summarize the problem:
An exercise asked me to launch a java application using the Windows 10 Command Line.
It taught me on a video how to add the IntelliJ path to the Environment Variables, so that, whenever I typed java Main I would get my Main.java/class application back.
The first problem that I had stumbled upon was that, instead of using java Main, I'd have to type java Main.java. I thought that it was due to a recent build for the JDK (v14.02), so I let that one pass.
The second problem that I had encountered was that, when the exercise asked me to launch an application using the package directories, the command line would return the following error: Error: Could not find or load main class com.pluralsight.organized.Main. Caused by: java.lang.ClassNotFoundException: com.pluralsight.organized.Main.

Revert whatever damage you've done to the system.
Install the Oracle JDK.
Put the Oracle JDK bin folder on your PATH variable.
Compile your code using javac Main.java
Run your compiled code using java Main
for the ones in the packages, you need to be at the package root, or have a class path to it. For example, let's consider a class com.example.Main
The folder structure should be:
D:/SomePath/com/example/Main.class
Then you need to be at D:/SomePath/ to execute java com.example.Main.
Alternatively, you could be anywhere else and execute java -cp D:/SomePath com.example.Main.

Could not find or load main class Javac

Quick note, I went through every single other question through here and nothing seems to work.
So, here is my issue. All I want to do is create a windows batch script that will be used to execute my selenium project on Jenkins. Sounds simple right ? Its probably is, but I am missing something...
Here is my project https://github.com/Daviditooe/Nomad
First command I tried:
javac src/nomad/execute/Execute.java
Execute.java:9: error: package nomad.sites does not exist import nomad.sites.MmaShare;
It also couldnt find any of the jars, so I add all of them
Then I tried:
javac -cp Jars\* src\nomad\execute\Execute.java
This fixed the jars issue but the package not found still exists
So then I tried compiling every single package at the same time
javac -cp Jars\* src\nomad\execute\*.java src\nomad\actions\*.java src\nomad\baseactions\*.java src\nomad\browsers\Chrome.java src\nomad\directory\*.java src\nomad\scripts\*.java src\nomad\sites\*.java src\nomad\urltools\*.java
So, now its not crashing, then I tried compiling...
java src\nomad\execute\Execute
And its giving me Could not find or load main class
So That last thing I tried was compile all of them at the same time.
java src\nomad\actions\MmaShareActions src\nomad\baseactions\BaseActions src\nomad\browsers\Chrome src\nomad\directory\Directory src\nomad\execute\Execute src\nomad\scripts\Vpn src\nomad\sites\MmaShare src\nomad\urltools\UrlTools
Still no luck... anything thoughts would be appreciated.

Again: You must go into the src folder before you execute javac and java!
I can compile and execute it on my Linux Laptop:
stefan#stefanpc:/hdd/stefan/Downloads/Nomad-master/src$ javac -cp '../Jars/*' nomad/execute/*.java nomad/actions/*.java nomad/baseactions/*.java nomad/browsers/Chrome.java nomad/directory/*.java nomad/scripts/*.java nomad/sites/*.java nomad/urltools/*.java
Note: nomad/baseactions/BaseActions.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
stefan#stefanpc:/hdd/stefan/Downloads/Nomad-master/src$ java -cp '../Jars/*:.' nomad.execute.Execute
Exception in thread "main" java.lang.IllegalStateException: The driver executable does not exist: /hdd/stefan/Downloads/Nomad-master/src/C:\Users\Davidito\Desktop\AutoLinks\Jars\chromedriver.exe
Of course my Linux machine does not have the chromedriver.exe installed.
Under Windows, you must use "\" instead of "/" and you must use ";" instead of ":". Note that you must add the current folder "." to the class path when you execute the program. Otherwise java would only search in the Jars folder.

Error: Could not find or load main class HelloWorldApp

I am pretty new to this but I seem to have a problem for a day now, and I can't get around it. Have looked over the other similar post but nothing worked. I just got the basic tutorial, made my Java file.
Used the javac HelloWorldApp.java command and got the class file.
But every time I try to run the java -cp . HelloWorldApp command, I get the Error: Could not find or load main class HelloWorldApp error. Pretty sure I am doing something wrong, just don't know what. I am on a Windows 7 machine with jdk1.8.0_31.

You can simply run your .class file with java filename command, provide you are running it from the src directory

Your current working directory may not be in your classpath, before running java class issue this command to include PWD into your classpath :
set CLASSPATH=%CLASSPATH%;.
java yourAppName

Running java from command line with packages: NoClassDefFoundError

I had a fully functional Java program that I am now trying to put into a package instead of having it in the default package. All of the .java files are in the mymap package, and I am trying to run black box tests in my MyMapTest.java file. The problem is that I don't know how to properly run this in the command line now that I have it in a package. I got stuck trying to google for answers.
I can get it to compile:
javac -cp "../junit.jar" *.java;
But when I try to run it as I previously had...
java -cp .:../junit.jar org.junit.runner.JUnitCore MyMapTest
I get the error java.lang.NoClassDefFoundError: mymap/MyMap for all of my tests. I guess the issue is that somehow I am not properly including mymap, perhaps in the classpath?
Similarly, I also have white box tests in MyMapWhiteBoxTest.java, where this file is also in the mymap package. I cannot figure out how to properly run these tests either. Trying to run it the same way, I get:
Exception in thread "main" java.lang.NoClassDefFoundError: MyMapWhiteBoxTest (wrong name: mymap/MyMapWhiteBoxTest)
For both cases, I have tried mymap/FILE or somehow also including the package in the classpath, but I'm definitely missing something.

If the main() is present in MyMapTest class then you can try the below command :
java -cp .:../junit.jar org.junit.runner.JUnitCore myMap.MyMapTest

After compilation: (javac -cp "../junit.jar" *.java;) what do you have in your current dir? You should have the file ./myMap/MyMapTest.class.

Cannot run simple compiled java program?

I am on Arch Linux, I just installed JRE and JDK and all the proper bin files (javac and java) are in /opt/java/bin/
I simply compiled a standard hello world, and compiled it with javac running javac ./hello.java and that made a class.
Now my problem is running it. I run java ./helloworld.class and it gives me an error, even if the file I point java to is non-existant:
Exception in thread "main" java.lang.NoClassDefFoundError: //helloworld/class
Caused by: java.lang.ClassNotFoundException: ..helloworld.class
(..omitted for clarity..)
Could not find the main class: ./helloworld.class. Program will exit.
You will notice the first line of the error, it munges the path //helloworld/class
When I feed java an absolute path, i.e java /home/foo/helloworld.class it gives the same error, but replaces the path's / with . in the first line, again munged.
What do you think is wrong? I really don't know why it is doing this..

When you run java, you just pass it the fully qualified class name (including package), not the file name.
java helloworld will look for helloworld.class.
java helloworld.class will look for helloworld/class.class

You do not run a file as
# java file.class
you run it as
# javac PATH/file.java
# java PATH/file
Do not add .class while using JAVA command.

Actually you should compile it like this
javac helloword.java
run the program
java helloword

And yet another thing: add command line option "-classpath ." or it short version "-cp .", i.e. your command line should look like:
java -cp . helloworld
this is if your class is in your current directory. Otherwise "." should be replaced by path where the class(es) may be found.