rfs-0 / java-modules

1. Analyze dependencies

• Set working directory to
• Find out which is the bottom module -> use jdeps build/libs/*.jar on user-service-consumer

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1. Modularize user domain module

• Find out which is the bottom module -> use jdeps build/libs/*.jar on user-service-consumer
• Add module-info.java to java folder of user-domain module
• Set working directory to user-domain module and execute jdeps -s build/libs/*.jar to see the resulting dependencies

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4. Execute bottom up migration: Modularize user service module

• Add module-info.java to java folder of user-service module
• Copy user-domain.jar to libs folder of user-service module
• Set working directory to user-service module and execute jdeps -s build/libs/*.jar to see the resulting dependencies

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5. Execute bottom up migration: Modularize user service provider one

• Assume we do not yet know the ch.resrc.consumers.user package is defined in more than one module
• Add module-info.java to java folder of user-service-provider-1 module
• Set working directory to user-service-provider-1 module and execute jdeps -s build/libs/*.jar to see the resulting dependencies

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6. Execute bottom up migration: Modularize user service provider two

• Add module-info.java to java folder of user-service-provider-2 module
• Set working directory to user-service-provider-2 module and execute jdeps -s build/libs/*.jar to see the resulting dependencies

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7. Execute bottom up migration: Modularize user service consumer

• Add module-info.java to java folder of user-service-consumer module
• Now the compile complains about reading package ch.resrc.consumer.user from both user-service-provider-1 and user-service-provider-2
• Fix split package by removing user-service-provider-2 and renaming user-service-provider-1 to user-service-provider
• Execute installDist
• Create dot files to visualize dependencies by executing: jdeps -dotoutput build/graphs build/install/application/lib/*.jar
• Set working directory to user-service-consumer module and execute jdeps -s build/libs/*.jar to see the resulting dependencies

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8. Create an executable with jlink

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Appendix

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Resources

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Commands

The follwoing commands assume the working directory to be module-examples/basic-example/application

Execute the application JAR via java command

java -p build/install/application/lib -m application/ch.resrc.application.Application

Create an executable for the application

To create an executable for the application execute: jlink --module-path $JAVA_HOME/jmods:build/install/application/lib --add-modules application --launcher application=application/ch.resrc.application.Application --output build/application --compress=2

Execute the executable of the application

This command executes the executable created via jlink: build/install/application/bin/application

Compare size of JDK to size of executable

Display size of JDK: du -h $JAVA_HOME Display size of executable: du -h build/application

List dependencies of modules (resp. JAR files) with jdeps

To analyze the dependencies of the modules execute: jdeps build/install/application/lib/*.jar To get a summary of the dependencies execute: jdeps -s build/install/application/lib/*.jar

Create dot files to visualize dependencies

jdeps -dotoutput build/graphs build/install/application/lib/*.jar

Create PNG files for the dot files

You need to install graphviz for this to work (brew install graphviz)

To create a png file for the dependency summary execute: dot -Tpng -Gdpi=300 build/graphs/summary.dot > build/graphs/summary.png For the application module execute: dot -Tpng -Gdpi=300 build/graphs/application.jar.dot > build/graphs/application.png For the service module execute: dot -Tpng -Gdpi=300 build/graphs/services.jar.dot > build/graphs/services.png