Makefile for java projects

Makefile

artifactId = a
directory = build
outputDirectory = $(directory)/classes/java/main
sourceDirectory = src/main/java
sources = $(shell find $(sourceDirectory) -name \*.java)
objects = $(sources:$(sourceDirectory)/%.java=$(outputDirectory)/%.class)
package = $(directory)/libs/$(artifactId).jar

JAR = jar
JAR_FLAGS = cvf
JAVA = java
JAVAC = javac
JAVAC_FLAGS = -g
COMPILE.java = $(JAVAC) -d $(outputDirectory) $(JAVAC_FLAGS)

.PHONY: all clean

all: $(package)

$(package): $(objects)

$(objects): $(outputDirectory)/%.class: $(sourceDirectory)/%.java
	$(COMPILE.java) $<

%.jar:
	mkdir -p `dirname $@`
	$(JAR) $(JAR_FLAGS) $@ -C $(outputDirectory) $(^:$(outputDirectory)/%=%)

clean:
	$(RM) -r $(directory)