Online java coding test compile submitted java code in nodejs

Question

I'm utilising the MEAN stack to create an online coding test app. Looking for a nodejs solution to compile and submit the Java code entered by the user in the editor. The user may enter the test parameters, execute it, and examine the results.

I found the solution below, which uses the exec approach

exec('java -jar userCode.jar',function (error, stdout, stderr){
});

However, this method does not appear to be practicable because it requires building a jar file from the user's java code before compiling it.

Is there a better way to solve this issue?

Answer 1

Given that the user's source code will be submitted as a single file:

You can use javac to convert the source code into an executable class, which you can then run with java.

Compiling:

javac -cp /path/to/libs/jar/files MyProgram.java

Executing:

java -cp .;/path/to/libs/jar/files  MyProgram

It'll work, but keep in mind the security implications. In essence, you're allowing the user to run untrusted code on your own server. Just make sure you run the code as an unprivileged user with no read/write privileges and no network access! Limit cpu shares and, if necessary, timeout the execution.