Compiling multiple packages using the command line in Java

Question

Hi i have been using an IDE but now I need to run and compile from the command line.

The problem is that I have multiple packages and I have tried to find the answer but nothing has worked.

So I have

src/
  Support/ (.java files)
  Me/ (.java files) 
  Wrapers/ (.java files)  

Do you know how to compile everything with javac?

Answer 1

You should use build tools like Maven or Ant for such tasks.

In the initial stages, when the project is not very complex you can use the following line to compile, with appropriate classpath in place(as suggested by @Michael):

javac Support/*.java Me/*.java Wrapers/*.java

Answer 2

javac is a compiler. What you need is a build system, which will be responsible for calling javac for multiple source files/paths.

One of the most popular tools doing that is Ant.

Answer 3

This should do it (may require additional classpath elements via the -cp command line switch):

javac Support/*.java Me/*.java Wrapers/*.java

But if your build process gets more complex (and it will!), you should look into using Apache Ant for build automation.

Answer 4

javac -d compiled $(find src -name *.java)

Answer 5

If you really need to just use javac and standard UNIX commands you could to this:

find src -name \*.java -print0 | xargs -0 javac -d classes

Answer 6

In many cases Ant is overkill. Just use a BAT file if you are in windows or a shell script (sh file) if you are in linux. You can create a text file which includes all your javac commands and just run that file when you want to build.

For example, I use the following bat file to build one of my apps:

@echo off
echo Building Shazaam...

del classes\com\aepryus\shazaam\*.* /q
del classes\com\aepryus\shazaam\engine\*.* /q
del classes\com\aepryus\shazaam\domain\*.* /q
del classes\com\aepryus\shazaam\persist\*.* /q
del classes\com\aepryus\shazaam\view\*.* /q
del classes\com\aepryus\shazaam\task\*.* /q
del classes\com\aepryus\shazaam\action\*.* /q
del classes\com\aepryus\shazaam\controller\*.* /q

javac src\com\aepryus\shazaam\*.java        -classpath \lib\AepUtil.jar;\lib\AepXML.jar;\lib\AepLoom.jar; -d classes
javac src\com\aepryus\shazaam\engine\*.java -classpath \lib\AepUtil.jar;\lib\AepXML.jar;\lib\AepLoom.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\domain\*.java -classpath \lib\AepUtil.jar;\lib\AepLoom.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\persist\*.java    -classpath \lib\AepUtil.jar;\lib\AepLoom.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\view\*.java   -classpath \lib\Servlet.jar;\lib\AepUtil.jar;\lib\AepXML.jar;\lib\AepLoom.jar;\lib\AepHTML.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\task\*.java   -classpath \lib\AepUtil.jar;\lib\AepLoom.jar;\lib\AepHTML.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\action\*.java -classpath \lib\Servlet.jar;\lib\AepUtil.jar;\lib\AepLoom.jar;\lib\AepHTML.jar;\lib\Sprout.jar;classes; -d classes
javac src\com\aepryus\shazaam\controller\*.java -classpath \lib\Servlet.jar;\lib\AepUtil.jar;\lib\AepXML.jar;\lib\AepRPC.jar;\lib\AepLoom.jar;\lib\AepHTML.jar;\lib\Sprout.jar;classes; -d classes

cd classes
jar cf ..\war\WEB-INF\lib\Shazaam.jar .
cd..

echo Complete