A makefile to compile Android projects from command line.

Makefile

# reverse URL parameters
DOMAIN=example
SUB_DOMAIN=helloandroid
# Name
SHORT_PROGNAME=helloandroid

# SDK path for version 29.0.2
SDK_PATH=/opt/android-sdk
BUILD_TOOLS_PATH=$(SDK_PATH)/build-tools/29.0.2
AAPT=$(BUILD_TOOLS_PATH)/aapt
DX=$(BUILD_TOOLS_PATH)/dx
ADB=$(SDK_PATH)/platform-tools/adb
ZIPALIGN=$(BUILD_TOOLS_PATH)/zipalign
APKSIGNER=$(BUILD_TOOLS_PATH)/apksigner
PLATFORM=$(SDK_PATH)/platforms/android-29/android.jar

.PHONY: compile clean wipe test

# test by installing app on a connected device
test: bin/$(SHORT_PROGNAME).apk
	@echo "Launching..."
	$(ADB) install -r $<
	$(ADB) shell am start -n com.$(DOMAIN).$(SUB_DOMAIN)/.MainActivity

src/com/$(DOMAIN)/$(SUB_DOMAIN)/R.java:
	@echo "Generating R.java file..."
	$(AAPT) package -f -m -J src -M AndroidManifest.xml -S res -I $(PLATFORM)

obj/com/$(DOMAIN)/$(SUB_DOMAIN)/%.class: src/com/$(DOMAIN)/$(SUB_DOMAIN)/%.java
	javac -d obj -classpath src -bootclasspath $(PLATFORM) -source 1.7 -target 1.7 $<

classes.dex: obj/com/$(DOMAIN)/$(SUB_DOMAIN)/R.class obj/com/$(DOMAIN)/$(SUB_DOMAIN)/MainActivity.class
	$(DX) --dex --output=classes.dex obj

bin/$(SHORT_PROGNAME).unaligned.apk: classes.dex
	@echo "Making APK..."
	$(AAPT) package -f -m -F bin/$(SHORT_PROGNAME).unaligned.apk -M AndroidManifest.xml -S res -I $(PLATFORM)
	$(AAPT) add bin/$(SHORT_PROGNAME).unaligned.apk classes.dex

bin/$(SHORT_PROGNAME).apk: bin/$(SHORT_PROGNAME).unaligned.apk release.jks
	@echo "Aligning and signing APK..."
	$(ZIPALIGN) -f 4 $< $@
	$(APKSIGNER) sign --ks release.jks $@ 

release.jks:
	keytool -genkeypair -validity 365 -keystore $@ -keysize 2048 -keyalg RSA -sigalg SHA256withRSA

clean:
	@echo "Cleaning..."
	rm -rf classes.dex
	rm -rf obj/*
	rm -rf src/com/$(DOMAIN)/$(SUB_DOMAIN)/R.java

wipe: clean
	@echo "Wiping..."
	rm -rf bin/*
	rm -rf release.jks