2. Java Project related questions
• How do we create a java project?
• How do we add dependencies?
• How do we create a runnable jar?
• How do we create a war?
• How do we execute tests?
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4. What is Maven?
• Apache Maven is a software project management.
• It is based on the concept of a Project Object Model
(POM)
• Maven can mange a project’s build, reporting a
documentation form a central piece of information
But it isn’t a mere build tool
4
5. Maven features
• Dependency System
• Multi-module builds
• Consistent project structure
• Consistent build model
• Plugin oriented
• Project generated sites
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6. Advantages over Ant
• Eliminate complicate scripts
• All the functionality required to build your project,
i.e., clean, compile, copy, resources, install, deploy
• Cross Project Reuse – Ant has no convenient way to
reuse target across projects.
6
9. POM
• Unit of work in Maven
• It is an XML file that contains the information and
the configuration details used by Maven to build the
project
9
10. Archetype
• It is a template of a project with is combined with
some user input to produce a working Maven project
• There are hundreds of archetypes to help us get
started
– $ mvn –version
– $ mvn archetype:generate
-DgroupId=com.mycompany.app -DartifactId=my-app
-DarchetypeArtifactId=maven-archetype-quickstart
-DinteractiveMode=true
– $ mvn eclipse:eclipse
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11. Artifact
• An artifact is a module obtained by another artifact
deployed to a maven repository
• Each artifact belongs to a group
• Each group can have more artifacts
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<dependency>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
<version>2.6</version>
</dependency>
12. Goals and Plugins
• Are an extension of the standard maven lifecycles
steps.
– Clean, compile, test, package, install and deploy
• There are plugin to do other steps such as
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<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.5.3</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
[...]
</plugin> </plugins>
13. What is Gradle?
• Gradle is a general purpose build system
• It comes with a rich build description
• language (DSL) based on Groovy
• It supports ”build-by-convention” principle
• But it is very flexible and extensible
• It has built-in plug-ins for Java, Groovy, Scala, Web
• Groovy as a base language allows imperative
programming in the build file.
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14. Advanced features
• Parallel unit test execution
• Dependency building
• Incremental build support
• Dynamic tasks and task rules
• Gradle daemon
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15. Hello, Gradle
• Create a file build.gradle
task hello << {
println 'Hello World'
}
• Run $ gradle hello
• Edit the file as below
task hello << {
print 'Hello '
}
task world(dependsOn: hello) << {
println 'World!"
}
• Run $ gradle –q world
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29. Extending your build
• Any Gradle script can be a plug-in:
apply from: 'otherScript.gradle'
apply from: 'http://mycomp.com/otherScript.gradle’
• Use many of the standard or 3rd-party plug-ins:
apply plugin: 'java'
apply plugin: 'groovy'
apply plugin: 'scala'
apply plugin: 'war'
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33. Sbt
• It is a tool to define task and then run them from the
shell
• To install on linux grab the
– rpm: https://dl.bintray.com/sbt/rpm/sbt-0.13.7.rpm
– deb: https://dl.bintray.com/sbt/rpm/sbt-0.13.7.deb
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34. Starting with sbt
• It is based on the file build.sbt
• Create a directory hello_scala
• Edit a file and add
lazy val root = (project in file(".")).
settings(
name.:=("hello”),
version := "1.0",
scalaVersion := "2.11.4"
)
• Create an HelloWorld class
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36. Running sbt
• It has a shell via $sbt
• Or we can run task in batch
– $ sbt clean compile "testOnly TestA TestB”
• It also support continuos delivery and run via
– > ~compile
– > ~run
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37. Creating a project definition
• To create a project in the build.sbt file
lazy val root = (project in file(.)).
settings(
organization := "com.example",
version := "0.1.0",
scalaVersion := "2.11.4"
)
• The build.sbt define a Project which holds a list of
scala expression called settings
• Moreover a build.sbt can have vals, lazy vals and defs
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38. SettingKey, TaskKey and InputKey
lazy val root = (project in file(".")).
settings(
name.:=("hello")
)
•.:= is a method that takes a parameter and return s
Setting[String]
lazy val root = (project in file(".")).
settings(
name := 42 // will not compile
)
•Does it run?
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39. Types of key
• SettingKey[T]: a key for a value computed once (the
value is computed when loading the project, and
kept around).
• TaskKey[T]: a key for a value, called a task, that has
to be recomputed each time, potentially with side
effects.
• InputKey[T]: a key for a task that has command line
arguments as input. Check out Input Tasks for more
details.
• The built-in key are field of the object Keys
(http://www.scala-
sbt.org/0.13/sxr/sbt/Keys.scala.html) 39
40. Custom Keys
• Can be created with their:
– settingKey, taskKey and inputKey
lazy val hello = taskKey[Unit](“An example task”)
• A TaskKey[T] can be used to define task such as
compile or package.
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41. Defining tasks and settings
• For example, to implement the hello task
lazy val hello = taskKey[Unit]("An example task”)
lazy val root = (project in file(".")).
settings(
hello := { println("Hello!") }
)
• Imports in build.sbt
import sbt._
import Process._
import Keys._
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42. Adding library dependencies
val derby = "org.apache.derby" % "derby" % "10.4.1.3"
lazy val commonSettings = Seq(
organization := "com.example",
version := "0.1.0",
scalaVersion := "2.11.4"
)
lazy val root = (project in file(".")).
settings(commonSettings: _*).
settings(
name := "hello",
libraryDependencies += derby
)
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43. Dependencies
• To add an unmanaged dependency there is the task
unmanagedBase := baseDirectory.value / "custom_lib”
• To add an managed dependency there is the task
libraryDependencies += groupID % artifactID % revision
• Or
libraryDependencies ++= Seq(
groupID % artifactID % revision,
groupID % otherID % otherRevision
)
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44. Resolvers
• To add a resolver
1. resolvers += name at location
2. resolvers += Resolver.mavenLocal
3. resolvers ++= Seq(name1 at location1, name2 at
location2)
• Is it possible also to define if the dependency is for
test
libraryDependencies += "org.apache.derby" % "derby" %
"10.4.1.3" % Test
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