[JAVA] About build tools

What is a build tool?

• The work up to deployment is actually "assembling applications and libraries in a format that can operate in the required execution environment", which is called build. * As work, compilation, linking external libraries, static analysis, testing, etc.
• Also, the word build has a broad meaning of "doing routine work". This time, I will use build not in a broad sense but in the sense of assembling to work in the above required environment.

Evolutionary flow of build

1. Human-powered build

• Large code takes a long time to compile and statically analyze, so I often had junior members do the build work.
• It is not good in terms of operation and quality to manually type commands for each release. So go to build script 2

2. Build script

• Collect the commands to be executed in the build work into a shell script or command file and hit it.
• However, even though the code can be compiled, the test code is wrong and it is useless to compile the big code, so the process that can not be handled by the build script is solved with the build tool of 3.

3. Build tool

• The build script process is divided so that it can be programmed whether to execute the next process according to the previous process result.
• Managing library dependencies. There is a "package manager" that specializes in this. javascript npm and Ruby RubyGems
• Monitor the file that is the input of the task, and automatically execute the task if there is a change. Grunt watch and Gradle continuous build

4. Continuous integration (CI) * From here, 4,5 is when you want to further improve the quality after using the build tool.

• The practice of building applications continuously, running automated tests, and always building ready-to-ship applications.

5. Continuous delivery or continuous deployment

• It is also possible to create a mechanism that can automatically release the latest product whenever the CI turns finely. This is called continuous delivery or continuous deployment.

Build Tools: Introducing various build tools

• GNU Make: A pioneer of build tools. Can be used in C C ++ builds.

• Ant

• Feature

• For java

• The default build file name is build.xml

• merit

• ant is also java, so you can go on multiple platforms

• Standard for eclipse, so incremental build

• Incremental build: Build only changes

• Demerit

• Since it is described in xml, the readability of the build file is low → It does not change even with Maven, it is solved with Gradle!

• It seems to write a build script declaratively, it is difficult to write a script → Is it solved with Maven?

• Maven

• Feature

• An alternative to ant! ??

• Define project structure in pom.xml

• Library-dependent resolution!

• Maven in the sense of resolving library dependencies and Maven in the sense of build tools. Be careful which one is used as the context. * That's how active it is in solving library dependencies! ,

• merit

• Created library-dependent management and "central repository"

• By bringing the convention to the project structure, the description of the build script is cleaner than ant.

• Demerit

• Previously, the build file was xml

• Even if the script is refreshing, it is still declarative, bound by conventions, and difficult to write.

• Gradle

• Feature

• The best of the build tools so far

• The default build script name is build.gradle

• There is also support for c c ++ object-c (Google Testing Framework is supported as standard)

• Google Testing Framework: better testing of c ++

• Default in Android Studio

• merit

• Free from xml, using Groovy

• Are you writing in Groovy script? Omit now, if you grow up!

• Library-dependent resolution possible with Maven repository

• Multi-project support

• The build tool itself has a built-in plugin mechanism. Can be expanded independently

• Unlike previous tools, each developer no longer needs to install the tool in their environment. Gradle can easily distribute executable files that can work with Standalon. * You do not have to down the library from the outside

• Demerit

• Requires understanding of DSL * DSL:domain specific language

• A computer language specialized for a specific purpose.

• Seems to be slow, as much as Ant

• Bazel

• It seems that it was taken up by the former Google tool, Cookpad Program, and attracted attention.

• Grunt

• For javascript

• It is called a build tool spear task runner.

• The build script name is Gruntfile. Write in JSON.

• Gulp

• For javascript

• Grunt's rivalry

• It seems to be compatible with Node.js

• SBT

• For Scala

• The build script name is build.sbt

Summary