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Java code runs through IDE but fails from terminal

I have a Java Code where I am able to run it on Intellij using custom configuration. The configuration has following attributes :-
module : java 8 (Oracle OpenJDK 1.8.0_321)
classpath : -cp XYZ.main()
main : com.ABC.XYZ.ManageTraffic
CLI arguements : server XYZ.yml
But when I try to run the jar that was build using gradle from terminal , it gives me Error , could not find or load main class com.ABC.XYZ.ManageTraffic
So far I have tried the following things looking at other solutions at Stackoverflow , still getting the same error
java -jar ques.jar
java -jar ques.jar com.ABC.XYZ.ManageTraffic
java -cp /build/libs/ques.jar com.ABC.XYZ.ManageTraffic
Just to cross check , I unzipped the creataed jar and found that com.ABC.XYZ.ManageTraffic class file is available there , still getting error. What could be the issue?

Run it from the IDE, and while it is running, try to get the command used by the IDE from the process list.
not sure what OS you are using but something like this should work on linux/mac:
ps -ef | grep java
After you have the command you can try to understand why its not working for you, or just use that command

Just want to add how I managed to run it. I created a new shaded jar file of the same application. refreshed its dependencies and now it works. I am yet to find out how creating a shaded jar instead of normal jar helped. Right now the only reason I could figure out is there may be version clashes with some dependencies but I wonder how it could throw could not found main class error.
Anyways , then I ran the file with the following command from terminal:
java -jar ./build/libs/ques-shaded.jar server XYZ.yml

Could not find or load main class org.testng.TestNG while running on ubuntu terminal

I am able to run the XML file from the eclipse but when I run the XML file from ubuntu terminal i am getting this error I tried the solution but not able to solve this problem
the command which I am using on Ubuntu
java -cp /home/dev2/eclipse-workspace/seffcon/bin:/home/dev2/eclipse-workspace/seffcon/libs* org.testng.TestNG testng.xml

Java command line using an imported jar

I am sure this is a stupid question and it must have been asked by every java programmer before. But I cannot find a related question at all.
This talks about subdirectories but I don't have any subdirectories as they are all in the same directory as the java file and the directory I executed the command line from Executable jar file error
This solution gives me the same error as I am writing below: Java command line with external .jar
Others (I don't have links to) talk about Eclipse and other IDE but I am not using an IDE, just a Linux terminal.
I am trying to import a public jar file from http://www.hummeling.com/IF97. The downloaded jar file has been renamed to if97.jar.
I have a java file called steam.java with these commands inside the file:
'
import com.hummeling.if97.IF97;
IF97 H2O = new IF97(IF97.UnitSystem.ENGINEERING);
System.out.println("test H2O table PSpecificEnthalpy(1): "+H2O.specificEnthalpyPT(1,300));
System.out.println("test H2O table PSpecificEnthalpy(5): "+H2O.specificEnthalpyPT(5,300));
'
But I do not know how to run this file in the command line.
I successfully compiled by typing:
'javac -cp if97.jar ~/test/steam.java'
Now I have a file called steam.class
But when I execute it with:
'java steam -cp if97.jar'
or
'java steam -jar if97.jar'
I get error:
Exception in thread "main" java.lang.NoClassDefFoundError: com/hummeling/if97/IF97
at steam.start(steam.java:364)
at steam.main(steam.java:341)
Caused by: java.lang.ClassNotFoundException: com.hummeling.if97.IF97
I am trying to execute this in Linux Ubuntu 16.04 using Terminal. Both the files (steam.java and if97.jar) are in the same Home directory where I execute the javac & java command on.
I believe (or I'm mistaken) that the problem is that java isn't able to find the jar file. But I don't know why.
Please advise, thank you in advance.

You need to specify the class name after the JVM options, because whatever coming after the class name are considered arguments for the class, not the JVM.
Try this:
'java -cp if97.jar steam'

Could not find or load main class Java Error Notepad++

I've implemented "Java Compile" and "Compile and Run" (the second as Java Compile and Run) as described in this answer: Java compile and run using notepad++ and nppexec.
Note: I'm using 1.8.0_20 rather than 1.7.0 as described in the answer.
However, when I try to run HelloWorld (as found here: http://docs.oracle.com/javase/8/javafx/get-started-tutorial/hello_world.htm) to test the compiler, I get the following response, including a "Could not find or load main class" error:
NPP_EXEC: "Java Compile and Run"
CD: C:\Users\Bova\Documents
Current directory: C:\Users\Bova\Documents
"C:\Program Files (x86)\Java\jdk1.8.0_20\bin\java" -classpath "C:\Users\Bova\Documents" "HelloWorld"
Process started >>>
Error: Could not find or load main class HelloWorld
<<< Process finished. (Exit code 1)
================ READY ================
What do I need to change to avoid this error?

I had this problem in Notepad++ too. What I did to fix it was I went to the Plugins menu, clicked on NppExec, and selected Follow $(CURRENT_DIRECTORY). After that I can run programs just fine.

The very first line of HelloWorld.java reads:
package helloworld;
Java packages are mapped to directories on the filesystem, so the interpreter expects to find HelloWorld.class inside a helloworld directory. Move the .class file to a helloworld subdir and run it as:
> java helloworld.HelloWorld
from the parent directory (i.e. the directory which contains helloworld/).

Java external library in terminal error

In terminal, I get the follow error after I compile my program:
WriteExcel.java:7: error: package jxl does not exist
I compiled the program by typing:
javac -cp /Desktop/folder/src/jxl.jar WriteExcel.java
Basically, how do I get the compiler to recognize the external library?