JBrownie is a wrapper around the system default javac Java compiler, that monitors Java sourcecode and automatically recompiles any files found changed.

The focus of this tool is to assist software developers, who prefer to use a plain text editors over a resourcehungry IDE, but still want their code to be autocompiled on the fly without delay and without having to manually start javac over and over again. Checking for syntax errors becomes now as easy as just saving the file in question.

JBrownie requires at least Java6 to run. Click here for a screenshot.


No Installation required. The program can be started from any directory as is. Note on classpath: The JVM does not accept -cp and -jar at the same time. If -jar is given, -cp (as well as the CLASSPATH environment variable, if set) is ignored. This means, that in order to prevent linker warnings, JBrownie must either not be started via -jar (the main class is called de.onyxbits.jbrownie.Core) or a project specific classpath must be submitted in the settings dialog under "Compile options".


JBrownie must be supplied with a base directory, containing the source code tree to watch. This can either be done from the commandline, by submitting the desired path as the first argument or from the file menu. Once a directory, it (and its subdirectories) will be scanned for files with the .java extension (case insensitive). Whenever such a file changes (or a new file is added), it will automatically be (re)compiled. The output of the compiler is printed to the main window of JBrownie.

Besides merely compiling class files, JBrownie can also be configured to to start the program in question.


Three aspects of the program can be configured currently: Compiler settings, Run Settings and GUI appearance. The menuitem to do so can be found in the "File" menu. Hitting the apply button in the settings dialog will automatically save the submitted values via java.lang.prefs.Preferences to the system dependent preferences storage.

Compiler settings

The commandline arguments to pass to the compiler. By default, the compiler is run without any options. It is not possible to change the compiler except by changing the JDK itself. The compiler that is used is always the default compiler of the JDK, with which JBrownie is run.

Run settings

This is simply the program (plus commandline argument) to associate with the "run program" button in the toolbar. By default, no program is set, meaning the button is without function. Once a program is run, it's stdout and stderr stream is redirected to JBrownie's console window.

GUI settings

These control the fontsize of the console and whether or not to use horizontal scrollbar for lines, that exceed the width of the window.


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