Kind of old question I know, but if you want to know command prompt for running Eclipse-based project (i.e the one that Eclipse uses)

1. Run your project into Eclipse
2. Goto Debug perspective
3. (on my screen anyway) Window in top left corner should have a little 'debug' tab.
4. Right click on name of your project, select Properties at the bottom of drop-down
5. Click on the 'Command Line' field (this is what you probably want).
6. Press [ctrl]+A & [ctrl]+C to select and copy
7. Either paste this into command line, or
8. (what I did) in Windows, create new *.bat text file and paste it in there ... now double clicking on that file should run your java proj.

Pretty useful if you wanna run something out of eclipse and are lazy like me.

BTW I needed this for exporting project for a uni assignment. Of course, they wanted to see code in *.java files too and above just uses *.class files Eclipse builds on the fly. To make batch compile your *.java files & then run you need to put together an appropriate javac command before the javaw line you got from process above and adjust accordingly - look at Java Docs for this. Eclipse has done most of hard work with library class paths though (I was using a few libs).

If you are referencing any external libraries, then you have to add them to the classpath. You can add it during compilation of the classes this way.

Go to the src directory and :

javac -classpath ".:<path_to_jar_file>" teamL/*.java

TO execute :

java -cp ".:<path_to_jar_file>" teamL.<class_name>

if your are using eclipse, then go to <project_directory>/bin/ here you can find the compiled classes (so you dont have to compile them) and directly run them using the above java command

Note: Since your classes are packaged under teamL package, you have to run the classes from outside the package by specifying the fully qualified name like teamL.ServiceEndpoint

First you compile your .java files

javac *.java

then you run it by typing,

java main

where main is the class with your main method, in the terminal.

Maven or Ant are the best option but for an Eclipse-only solution
you can choose File -> Export and select Java -> Runnable JAR File
then transfer the JAR file to your other machine and run this from the command line:

java -jar YOUR.JAR

cd into the directory in which your Calculator.java file is stored, run

javac Calculator.java

this will create a file Calculator.class. You can now run the compiled class with

java Calculator

mind that there is no .class to be added!

It's important to note that you can't just run arbitrary Java code, but have to have some structure set up (for example, if you're going to call a method, what arguments are you passing in?) To run a specific piece of Java code, you should consider creating a main method in that class that just launches some specific piece of code under the constraints that you'd like. One way to do this would be to add a method public static void main(String[] args) containing the code you want to run. Once you've done this, you can right-click on it, choose the "Run as..." option, and select "Java application" to run the program you've written.

Alternatively, if you just want to check whether some specific piece of code is working, you could consider using JUnit to write unit tests for it. You could then execute the JUnit test suite from Eclipse to check whether that specific piece of code is functioning correctly. This is what I would suggest doing, as it makes it possible to test the software through every step of the development.

Hope this helps!

You can't compile & run just one file in Eclipse without the file being in a java project.

It is a very quick and easy process to create a Java Project in eclipse.

File -> New -> Java Project

You can use the default package (though it is not recommended) and put your single file in it and run it.