Intro to Gradle for FRC

Delivered at StuySplash for FIRST Robotics Challenge Team 694.

Transcript

1. @jeanneboyarsky 1
   Intro to Gradle For FRC
   Jeanne Boyarsky
   Saturday December 14, 2019
   StuySplash
   speakerdeck.com/boyarsky
   

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2. @jeanneboyarsky
   About Me
   • 11 year FRC volunteer
   • Professional Programmer
   • Java Champion (about 300 in
   the world)
   • Build Tool Expert
   • And…
   2
   

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3. @jeanneboyarsky
   Pause for a Commercial
   3
   Java 11 certs
   •1Z0-815 - Out now
   •1Z0-816 - April ETA
   

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4. @jeanneboyarsky
   Volunteer?
   4
   NYC FRC Regional
   Co-Volunteer
   Coordinator
   firstinspires.org
   

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5. @jeanneboyarsky
   Agenda
   • Quick Java PSA
   • Intro to Build Tools
   • Intro to Gradle
   • Using Gradle for FRC
   • More on Groovy/Gradle
   5
   

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6. @jeanneboyarsky
   Java Release Cycle
   6
   

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7. @jeanneboyarsky
   “Java is Still Free”
   • Free for non-production use
   • For Prod use
   20 minute version:
   https://medium.com/@javachampions/java-
   is-still-free-2-0-0-6b9aa8d6d244
   7
   

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8. @jeanneboyarsky
   Agenda
   • Quick Java PSA
   • Intro to Build Tools
   • Intro to Gradle
   • Using Gradle for FRC
   • More on Groovy/Gradle
   8
   

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9. @jeanneboyarsky
   What is a Build Tool?
   • Automated
   • Creates executable
   • Reproduceable
   • Codified
   9
   

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10. @jeanneboyarsky
    Find the build tool?
    10
    Saw?
    Band Saw?
    CNC Machine?
    x Not automated
    x Automation != Electricity
    ✔Programming
    x But doesn’t create executable
    

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11. @jeanneboyarsky
    Happy Birthday Make
    • 1976
    • C
    • Makefile
    • Compiles code
    • Adds libraries
    • Can call OS commands
    11
    

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12. @jeanneboyarsky
    Big 3 Java Build Tools
    • Ant
    • Maven
    • Gradle
    12
    

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13. @jeanneboyarsky
    Quick Comparison
    13
    Ant Maven Gradle
    Released 2000 2004 2007
    Build file build.xml pom.xml build.gradle
    Language XML XML Groovy
    Dependency
    mgmt?
    Not native Yes Yes
    

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14. @jeanneboyarsky
    FRC Timeline
    • 2004-2008 - IFI
    • 2009-2014 - cRIO with Java
    • Java 1.4 Mobile
    • 2015-? - RoboRIO with Java
    • Multi core
    • Current versions of Java
    14
    

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15. @jeanneboyarsky
    FRC Timeline
    • 2010-2018
    • Ant
    • 2019-?
    • Gradle
    15
    

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16. @jeanneboyarsky
    Agenda
    • Quick Java PSA
    • Intro to Build Tools
    • Intro to Gradle
    • Using Gradle for FRC
    • More on Groovy/Gradle
    16
    

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17. @jeanneboyarsky
    Convention over
    Configuration
    • Many defaults
    • Directory structure:
    • src
    • main
    • java
    17
    

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18. @jeanneboyarsky
    Benefits
    • Less code to build
    • Fewer decisions to make
    • Faster to switch between teams
    • Easier to work on open source
    18
    

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19. @jeanneboyarsky
    Phases
    19
    Initialization
    Counts gradle projects
    (1 Robot)
    Configuration Parses the build script
    Execution Determines which
    tasks to execute
    and does so
    

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20. @jeanneboyarsky
    First Install
    20
    

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21. @jeanneboyarsky
    First Build
    • Download dependencies from
    internet
    • Cached
    21
    

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22. @jeanneboyarsky
    Simplest build.gradle
    apply plugin: ‘java'
    • compiles into build/classes
    • creates JAR into build/libs
    All that from one line!
    22
    

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23. @jeanneboyarsky
    Key Gradle Files
    23
    File Description
    build.gradle The build script
    gradlew Gradle wrapper so can run
    without installing Gradle
    on Mac/Linux
    gradlew Same for Windows
    settings.gradle Sets projects specific config
    before build runs
    

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24. @jeanneboyarsky
    Gradle Directories
    24
    Directory Description
    .gradle Cache
    .wpilib FRC specific. Contains
    metadata. Ex: build year,
    team number
    vendordeps JSON files with locations for
    some dependencies
    

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25. @jeanneboyarsky
    JAR
    • Java Archive
    • Like zip file
    • Contains compiled code
    • You depend on these libraries
    25
    

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26. @jeanneboyarsky
    Dependency
    • Often hosted on binary
    repository
    • ex: Maven Central
    • Some FRC plugins not in
    Central
    • vendordeps!
    26
    

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27. @jeanneboyarsky
    Agenda
    • Quick Java PSA
    • Intro to Build Tools
    • Intro to Gradle
    • Using Gradle for FRC
    • More on Groovy/Gradle
    27
    

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28. @jeanneboyarsky
    If not deploying
    • ./gradlew clean
    • ./gradlew build
    28
    

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29. @jeanneboyarsky
    From command palette
    > Executing task: ./gradlew deploy -
    PteamNumber=694 --offline -
    Dorg.gradle.java.home="/Library/Java/
    JavaVirtualMachines/jdk-11.0.2.jdk/
    Contents/Home" <
    29
    -P = project property
    -D = system property
    

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30. @jeanneboyarsky
    Build Gradle Walkthru
    30
    

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31. @jeanneboyarsky
    Build Gradle Walkthru
    31
    

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32. @jeanneboyarsky
    Build Gradle Walkthru
    32
    

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33. @jeanneboyarsky
    Build Gradle Walkthru
    33
    

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34. @jeanneboyarsky
    Build Gradle Walkthru
    34
    

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35. @jeanneboyarsky
    Build Gradle Walkthru
    35
    

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36. @jeanneboyarsky
    Build Gradle Walkthru
    36
    

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37. @jeanneboyarsky
    Build Gradle Walkthru
    37
    

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38. @jeanneboyarsky
    Settings Gradle Walkthru
    38
    

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39. @jeanneboyarsky
    Settings Gradle Walkthru
    39
    

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40. @jeanneboyarsky
    Agenda
    • Quick Java PSA
    • Intro to Build Tools
    • Intro to Gradle
    • Using Gradle for FRC
    • More on Groovy/Gradle
    40
    

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41. @jeanneboyarsky
    Different Java for Class?
    1) VS Code Settings
    41
    

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42. @jeanneboyarsky
    Different Java for Class?
    2) /.gradle/
    gradle.properties
    42
    org.gradle.java.home=/Library/Java/
    JavaVirtualMachines/jdk-11.0.2.jdk/
    Contents/Home
    

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43. @jeanneboyarsky
    Groovy
    43
    8
    Groovy
    Java
    

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44. @jeanneboyarsky
    Java -> Groovy
    int lastYear = 2017;
    int year = 2018
    def nextYear = 2019
    44
    Can use Java
    syntax
    Without semicolon or type
    

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45. @jeanneboyarsky
    Strings
    def city = 'SF'
    println 'Here: $city'
    println "Here: $city"
    println "In ${city.class}"
    45
    Java String
    GString
    Here: $city
    Here: SF
    In class java.lang.String
    

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46. @jeanneboyarsky
    Multi Line String
    def name = 'Jeanne'
    def text = """
    Name
    ______
    $name
    """
    println text
    46
    Coming soon to
    Java with new
    syntax
    Name
    ______
    Jeanne
    

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47. @jeanneboyarsky
    What does this print?
    def name = 'Jeanne'
    def text = ’’’
    Name
    ______
    $name
    ’’’
    println text
    47
    Name
    ______
    $name
    

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48. @jeanneboyarsky
    Getters vs Properties
    def animal = 'dog'
    println animal.getBytes()
    println animal.bytes
    48
    

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49. @jeanneboyarsky
    == vs equals()
    def monday ='monday'
    def nextMonday = new
    String('monday')
    def tuesday ='tuesday'
    println monday == null
    println null == monday
    println monday == tuesday
    println monday == nextMonday
    49
    Java
    Syntax
    True!
    

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50. @jeanneboyarsky
    What is the Truth?
    50
    Value Result
    Null FALSE
    Empty String FALSE
    Empty List FALSE
    1 Character String TRUE
    

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51. @jeanneboyarsky
    Elvis has entered the building
    println Jenkins.instance
    .getItemByFullName(jobName)
    ?.lastBuild
    ?.timestamp
    ?.time
    51
    

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52. @jeanneboyarsky
    Optional Parens
    def ch = 'abc'.charAt 1
    println ch
    52
    Optional when no ambiguity
    Ambiguity:
    * Zero params
    * Within println
    

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53. @jeanneboyarsky
    ArrayList++
    53
    def list = ['cookie',
    'chocolate’]
    list << 'candy'
    println list.getClass() class
    java.util.ArrayList
    println list[1] chocolate
    ArrayList does what now?
    

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54. @jeanneboyarsky
    ArrayList++
    54
    println list [cookie, chocolate,
    candy]
    println list[-1] candy
    println list.min() candy
    list.sort()
    println list [candy, chocolate,
    cookie]
    

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55. @jeanneboyarsky
    Functions
    incrementBy = 4;
    def add(num) {
    num + incrementBy
    }
    println add(2)
    55
    no def
    types optional
    return optional
    

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56. @jeanneboyarsky
    IT
    (10..1).each{ println "--> $it" }
    println 'Blast off!'
    56
    

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57. @jeanneboyarsky
    Named Params
    def config = new
    SelectorConfiguration(
    name: ‘selector',
    description: ‘packages',
    )
    57
    Only the default
    constructor
    exists!
    

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58. @jeanneboyarsky
    Alfred vs Edwin
    File file = new File("src/main/java/frc/robot/RobotMap.java")
    System.out.println("=========================")
    if(file.text.contains('ROBOT_NAME = "Alfred"')) {
    System.out.println("Built to ALFRED!!!")
    } else if(file.text.contains('ROBOT_NAME = "Edwin"')) {
    System.out.println("Built to EDWIN!!!")
    } else {
    System.out.println("[ATTENTION] Look at RobotMap and make
    sure you have robot name set!")
    throw new IllegalStateException("Robot Name Not Found");
    }
    System.out.println("=========================")
    58
    

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59. @jeanneboyarsky
    Book Giveaway
    59
    

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60. @jeanneboyarsky
    Questions
    ?
    60
    

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