1. PROJECT JIGSAW – INTEGRATION WITH TOOLS
JavaOne
SAN FRANCISCO
Alexandru Jecan
Software Engineer | Author |
Trainer | Speaker | Consultant

2. SUMMARY 1 2 3 4 5 6 7 Integration with Build Tools Apache Maven
Maven Compiler Plugin 4
Maven Exec Plugin 5
Backward Compatibility Using Maven Toolchain Plugin Toolchain Plugin 6
Maven JDeps Plugin 7
Maven Jmod Plugin 02
PROJECT JIGSAW – INTEGRATION WITH TOOLS

3. SUMMARY 8 9 10 11 12 Maven Jlink Plugin Maven Dependency Plugin Gradle
Ant 12
Loom 03
PROJECT JIGSAW – INTEGRATION WITH TOOLS

4. SUMMARY 13 14 15 Moditect SonarJava Graphviz Gradle Ant Loom04
PROJECT JIGSAW – INTEGRATION WITH TOOLS

5. SUMMARY 16
Integration with Integrated Development Environments 17
NetBeans support 18
Eclipse support 19
Intellij IDEA support 20
JDK 9 Ready Status 21
JDK 9 Ready Libraries 22
Status Modularization Third-party Libraries 05
PROJECT JIGSAW – INTEGRATION WITH TOOLS

6. SUMMARY 23 24 25 26 27 28 29 Modularized Third-party Libraries
How to Modularize a Library 25
Encapsulated JDK internal APIs 26
Not resolved platform modules 27
Cyclic dependencies 28
Split packages 29
Java 9 Modularity Revealed book 06
PROJECT JIGSAW – INTEGRATION WITH TOOLS

7. QUESTION
What do you expect from a tool to do in order to make development using Jigsaw easier? 07
PROJECT JIGSAW – INTEGRATION WITH TOOLS

8. INTEGRATION WITH BUILD TOOLS
Jigsaw
Build Tools
Strong encapsulation
Build the project
Services
Central repository
Link into run-time images
Dependency management
Download artifacts
Reliable configuration
Record dependencies
Record artifacts
Verify at compile time and run time
Verify for compilation
Select artifacts for compilation
The Java Module System, Nicolai Parlog, Manning 08
PROJECT JIGSAW – INTEGRATION WITH TOOLS

9. INTEGRATION WITH BUILD TOOLS
Prior to JDK 9
Build Tools
Class path
JDK 9+
Class path
Build Tools
Module path 09
PROJECT JIGSAW – INTEGRATION WITH TOOLS

10. APACHE MAVEN Only Maven 3+ supports Java 9
No changes were performed in Maven Core in order to make Maven run on Java 9
Maven can also use the module path for compilation (besides the class path)
Normal modules as well as automatic modules can be defined as dependencies
The presence of module-info.java decides if Maven uses the module path or not 10
PROJECT JIGSAW – INTEGRATION WITH TOOLS

11. APACHE MAVEN
The <groupId>, <artifactId> and <version> from pom.xml are not related to the name of the module from module-info.java
To add a dependency in pom.xml, the Maven specific names are used, as before
To require a module in module-info.java, the name of the module from the module descriptors is used 11
PROJECT JIGSAW – INTEGRATION WITH TOOLS

12. MAVEN COMPILER PLUGIN
Offers support for JPMS starting with version 3.6.0
Latest version = (as of September 2017)
Requires JDK 7+
source and target have to be minimum 6
Module-info is compiled as well
During the compile phase, when a module-info.java file is found, it automatically switches to the module path 12
PROJECT JIGSAW – INTEGRATION WITH TOOLS

13. MAVEN COMPILER PLUGIN
Flags like --add-modules or --add-exports can be added directly in the pom.xml
<compilerArgs>
<arg>--add-modules</arg>
<arg>java.xml.bind</arg>
</compilerArgs>
<compilerArgs>
<arg>--add-exports</arg>
<arg>java.base/sun.net=myModule</arg>
</compilerArgs> 13
PROJECT JIGSAW – INTEGRATION WITH TOOLS

14. MAVEN COMPILER PLUGIN PROJECT JIGSAW – INTEGRATION WITH TOOLS
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.0</version>
<executions>
<execution>
<id>example</id>
<goals>
<goal>compile</goal>
</goals>
<configuration>
<compilerArgs>
<arg>--add-exports</arg>
<arg>java.base/sun.net=myModule</arg>
<arg>--add-modules</arg>
<arg>java.xml.bind</arg>
</compilerArgs>
</configuration>
</execution>
</executions>
</plugin> 14
PROJECT JIGSAW – INTEGRATION WITH TOOLS

15. MAVEN COMPILER PLUGIN
A new tag called <release>, which has greater precendence over the <source> and <target> tags
<release> corresponds to the option “maven.compiler.release”
For providing backward compatibility:
1) Module-info should be compiled with --release 9
2) All the other sources compiled with --source < 9 and --target < 9 15
PROJECT JIGSAW – INTEGRATION WITH TOOLS

16. MAVEN EXEC PLUGIN Java 9 Modularity Sander Mak, Paul Bakker, O’Reilly
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.6.0</version>
<executions>
<execution>
<goals>
<goal>exec</goal>
</goals>
</execution>
</executions>
<configuration>
<executable>${JAVA_HOME}/bin/java</executable>
<arguments>
<argument>--module-path</argument>
<modulepath/>
<argument>--module</argument>
<argument>{myMainClass}</argument>
<argument>${myArgument}</argument>
</arguments>
</configuration>
</plugin>
Java 9 Modularity
Sander Mak,
Paul Bakker,
O’Reilly 16
PROJECT JIGSAW – INTEGRATION WITH TOOLS

17. BACKWARD COMPATIBILITY WITH MAVEN TOOLCHAIN PLUGIN
Solves JEP 247: Compile for Older Platform Versions
With toolchains, we can specify the JDKs installed on our system
A project can be built using a specific version of the JDK that is independent from the one Maven is running with
To use Toolchains:
1) The maven-toolchain-plugin should be adjusted
2) The toolchains.xml file should be adjusted 17
PROJECT JIGSAW – INTEGRATION WITH TOOLS

18. BACKWARD COMPATIBILITY WITH MAVEN TOOLCHAIN PLUGIN
Toolchains required when we have the module-info.java file inside the sources and we want to compile it with an older version of Java 18
PROJECT JIGSAW – INTEGRATION WITH TOOLS

19. MAVEN JDEPS PLUGIN discover all static dependencies of a library
JDeps can:
discover all static dependencies of a library
discover the usages of internal JDK APIs
automatically generate a module descriptor for a JAR file
Maven JDeps Plugin has two goals:
jdkinternals => checks if main classes depend on JDK-internal classes
test-internals => checks if test classes depend on JDK-internal classes 19
PROJECT JIGSAW – INTEGRATION WITH TOOLS

20. MAVEN JDEPS PLUGIN
A compilation is necessary, since JDeps uses classes and not sources
Should be used to test if your project is ready for JDK 9
By setting the <failOnWarning> option to true, the build will immediately fail if there are any warnings 20
PROJECT JIGSAW – INTEGRATION WITH TOOLS

21. MAVEN JDEPS plugin PROJECT JIGSAW – INTEGRATION WITH TOOLS
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jdeps-plugin</artifactId>
<version>3.0.0</version>
<executions>
<execution>
<id>testOnClasses</id>
<goals>
<goal>jdkinternals</goal>
<goal>test-jdkinternals</goal>
</goals>
</execution>
<id>testOnDependencies</id>
<configuration>
<failOnWarning>false</failOnWarning>
<recursive>true</recursive>
</configuration>
</executions>
</plugin> 21
PROJECT JIGSAW – INTEGRATION WITH TOOLS

22. MAVEN JMOD PLUGIN Pre-release version (as of September 2017)
First version = alpha-1
Works with Maven 3+ and JDK 7+
Can create JMOD files (create goal)
Can list the content of a JMOD file (list or describe goal) 22
PROJECT JIGSAW – INTEGRATION WITH TOOLS

23. MAVEN JLINK PLUGIN Pre-release version (as of September 2017)
First version = alpha-1
Works with Maven 3+ and JDK 7+
Can create Modular Run-Time Images via Jlink from jar /JMOD files (jlink goal)
Has parameters like: <addModules>, <bindServices>, <compression>, <limitModules>, etc. 23
PROJECT JIGSAW – INTEGRATION WITH TOOLS

24. MAVEN DEPENDENCY PLUGIN
The list option lists the groupId, artifactId together with the name of the module 24
PROJECT JIGSAW – INTEGRATION WITH TOOLS

25. GRADLE
Works since the --illegal-access=permit option was set as default
No --add-opens options necessary to build Gradle
No first class support for Java 9 modules as of
Running Java 9 on Gradle 4.1+ is supported
Example of producing a multi-release JAR with Gradle =>
Work in progress 25
PROJECT JIGSAW – INTEGRATION WITH TOOLS

26. ANT
Ants java, javac and junit understand the new command-line parameters that are specific to JDK 9 modules
Support for module path and upgrade module path added in Ant 1.9.7
Single module and multi module compilation supported
Since Ant and :
<java>, <javac> and <junit> support JDK 9 modules
Support for javac --release option
ant.java.version holds the value “9” 26
PROJECT JIGSAW – INTEGRATION WITH TOOLS

27. LOOM Modern and lightweight build tool for Java 9+ YAML configuration
Convention over configuration
Build with Java 9 => first-class JPMS support
(Optional) Minimalistic configuration
Dependency resolution (powered by the Apache Maven Repository)
Support for Junit 5, Checkstyle, SpotBugs, PMD, IntellijIDEA, Eclipse 27
PROJECT JIGSAW – INTEGRATION WITH TOOLS

28. LOOM https://loom.builders/
Loom source code =>
Loom documentation =>
Examples with Loom => 28
PROJECT JIGSAW – INTEGRATION WITH TOOLS

29. MODITECT https://github.com/moditect/moditect Maven plugin
Can generate module-info.java descriptors for given artifacts on behalf of the specific information written by developers in pom.xml
Can add module descriptors to JAR files
Can create modular runtime images 29
PROJECT JIGSAW – INTEGRATION WITH TOOLS

30. SonarJAVA
Support for JPMS starting from version 4.11
Recognizes new keywords related to modules from Java 9
Able to recognize and parse module-info.java
Can handle the directives from module-info.java: requires, exports, opens, uses and provides
ModuleDeclaration:
{Annotation} [open] module Identifier {. Identifier} {
{ModuleDirective} } 30
PROJECT JIGSAW – INTEGRATION WITH TOOLS

31. GRAPHVIZ Example for Windows: Open source graph visualization software
Creates a graphical representation of Jigsaw modules and their dependencies:
Example for Windows:
jdeps -dotoutput jdeps-dotoutput modules/*.jar \Tools\Graphviz\release\bin\dot.exe –Tpng
jdeps-dotoutput/summary.dot > graphviz-summary.png
start graphviz-summary.png 31
PROJECT JIGSAW – INTEGRATION WITH TOOLS

32. INTEGRATION WITH INTEGRATED DEVELOPMENT ENVIRONMENTS
NetBeans Support
Eclipse Support
Intellij IDEA Support 32
PROJECT JIGSAW – INTEGRATION WITH TOOLS

33. NETBEANS SUPPORT NetBeans 9 runs on top of JDK 8 as well as JDK 9
Support for JDK 9 starting from NetBeans 9
NetBeans 9 not yet officialy released (as of )
NetBeans 9 runs on top of JDK 8 as well as JDK 9
Two options:
1) Build with Ant from:
2) Download the latest Development build from:
JDK 8 is mandatory for building NetBeans 9; cannot use JDK 9 or JDK 7 or older 33
PROJECT JIGSAW – INTEGRATION WITH TOOLS

34. NETBEANS SUPPORT New Project Type => Java Modular Project
One NetBeans project now supports multiple
Jigsaw modules
Support for Maven projects
Set netbeans_jdkhome in netbeans.conf to point
to JDK 9 installation 34

35. NETBEANS SUPPORT
Support for adding module-info (New =>Other => Java => Java Module Info) => supports code completion 35
PROJECT JIGSAW – INTEGRATION WITH TOOLS

36. NETBEANS SUPPORT Support for module path
Edit – Compile – Debug cycle supported 36
PROJECT JIGSAW – INTEGRATION WITH TOOLS

37. NETBEANS SUPPORT
Go to Tools => Java Platforms and verify that it is running on JDK 9
Project property can be set to JDK 9
Source/binary format for files can be set to JDK 9 37
PROJECT JIGSAW – INTEGRATION WITH TOOLS

38. NETBEANS SUPPORT Module Dependency Graph using the Graph View 38
PROJECT JIGSAW – INTEGRATION WITH TOOLS

39. NETBEANS SUPPORT
Support for packaging project files into a custom run-time using Jlink 39
PROJECT JIGSAW – INTEGRATION WITH TOOLS

40. NETBEANS SUPPORT JShell integration 40

41. ECLIPSE SUPPORT Eclipse Oxygen with Java 9 support
For Java 9 support, you can also update other Eclipse IDE to Eclipse 4.7. More info => 41
PROJECT JIGSAW – INTEGRATION WITH TOOLS

42. ECLISE SUPPORT Add JRE and JDK 9 as installed JRE
Support for JavaSE-9 execution environment
Module compilation
IDE can be launched with JDK 8 or JDK 9
Support for module path + class path 42
PROJECT JIGSAW – INTEGRATION WITH TOOLS

43. INTELLIJ IDEA SUPPORT
Support for Jigsaw modules starting from version
Enhancements in versions and
Code completion in the module-info
Each Jigsaw module has to correspond to an Intellij IDEA module
For a module, “Mark directory as => Sources root” 43
PROJECT JIGSAW – INTEGRATION WITH TOOLS

44. INTELLIJ IDEA SUPPORT
Supports module path, class path, module path + class path 44
PROJECT JIGSAW – INTEGRATION WITH TOOLS

45. INTELLIJ IDEA SUPPORT 45
PROJECT JIGSAW – INTEGRATION WITH TOOLS

46. INTELLIJ IDEA SUPPORT 46
PROJECT JIGSAW – INTEGRATION WITH TOOLS

47. Intellij idea support 47
PROJECT JIGSAW – INTEGRATION WITH TOOLS

48. INTELLIJ IDEA SUPPORT Package not exported => “Package not found”
No readability defined in module-info 48
PROJECT JIGSAW – INTEGRATION WITH TOOLS

49. INTELLIJ IDEA SUPPORT
Recognizes when a platform module is not required
Can suggest to add missing requires clauses in module-info 49

50. INTELLIJ IDEA SUPPORT Code completion in module-info
Code completion for exporting packages 50

51. INTELLIJ IDEA SUPPORT
Both Intellij IDEA module dependencies as well as Jigsaw module dependencies have to be declared
module com.javaone.application {
requires com.javaone.service; } 51
PROJECT JIGSAW – INTEGRATION WITH TOOLS

52. INTELLIJ IDEA SUPPORT Dependency Diagram for Java 952
PROJECT JIGSAW – INTEGRATION WITH TOOLS

53. INTELLIJ IDEA SUPPORT Opens clause in open module not allowed
Duplicate clauses in module-info detected 53
PROJECT JIGSAW – INTEGRATION WITH TOOLS

54. INTELLIJ IDEA SUPPORT Find usages 54
PROJECT JIGSAW – INTEGRATION WITH TOOLS

55. INTELLIJ IDEA SUPPORT Inspection
Possibility to highlight the automatic modules, etc. 55
PROJECT JIGSAW – INTEGRATION WITH TOOLS

56. INTELLIJ IDEA SUPPORT Support for Maven projects
Automatically runs with the module path instead of class path
Quick fixes for adding items in the module-info.java file 56
PROJECT JIGSAW – INTEGRATION WITH TOOLS

57. JDK 9 READY STATUS (AS OF 24.09.17) 57
PROJECT JIGSAW – INTEGRATION WITH TOOLS

58. JDK 9 READY LIBRARIES (AS OF 24.09.17)
Library Name
JDK 9 Ready
JDK 9 Ready starting from Version
Apache Derby
Yes
Apache Log4j
2.9.0
Apache Lucene / Solr
7.0 (for both Lucene and Solr)
Apache Maven
3.0
Apache PDFBox
2.0.8
Apache POI
3.17 bt
CruiseControl
GraphHopper 58
PROJECT JIGSAW – INTEGRATION WITH TOOLS

59. JDK 9 READY LIBRARIES (AS OF 24.09.17)
Library Name
JDK 9 Ready
HeapStats
Yes
Hibernate
Jackson
JaCoCo
JITWatch
JOSM
Junit 5
LWJGL
Rapidoid 59
PROJECT JIGSAW – INTEGRATION WITH TOOLS

60. JDK 9 READY LIBRARIES (AS OF 24.09.17)
Library Name
JDK 9 Ready
RedHat Wildfly
Yes
RxJava
Spotbugs
Woodstox 60
PROJECT JIGSAW – INTEGRATION WITH TOOLS

61. JDK 9 READY SOON LIBRARIES (AS OF 24.09.17)
Library Name
Apache JMeter
DataCleaner
Golo
JLine
Roaring
Apache MetaModel
Drools
Groovy
Jboss-Forge
Spring Framework
Apache Tomcat
EasyMock
Hazelcast
Kotlin
ZXing
Apache Tika
Eclipse Jetty
HSQLDB
Objenesis
Byteman
Ehcache
JavaEWAH
OptaPlanner
Classworlds
ElasticSearch
JBoss Tools
oVirt engine 61
PROJECT JIGSAW – INTEGRATION WITH TOOLS

62. STATUS MODULARIZATION THIRD-PARTY LIBRARIES62
PROJECT JIGSAW – INTEGRATION WITH TOOLS

63. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
Accumulo No
ActiveMQ
Ambari
Ant
Aurora
Avro
Axis
Cassandra
CloudStack
Cordova
CouchDB 63
PROJECT JIGSAW – INTEGRATION WITH TOOLS

64. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
EclipseLink No
Falcon
Flex
Flume
Geronimo
Grails
Groovy
Guava
Hadoop
Hbase
Hibernate 64
PROJECT JIGSAW – INTEGRATION WITH TOOLS

65. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
Jackrabbit No
Jackson
JDO
Jersey
Jetty
Joda
Jsoup
Kafka
Knox
Log4j
Lombok 65
PROJECT JIGSAW – INTEGRATION WITH TOOLS

66. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
Lucene No
Mahout
Maven
Mesos
Mockito
Oozie
OpenJPA
Perl
Pig
PowerMock
Quarz 66
PROJECT JIGSAW – INTEGRATION WITH TOOLS

67. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
SLF4J
Yes
Spark No
Spring
Struts
Subversion
SWT
Tapestry
TestNG
Tiles
Tomcat
Vaadin 67
PROJECT JIGSAW – INTEGRATION WITH TOOLS

68. MODULARIZED THIRD-PARTY LIBRARIES
Library Name
Modularized (as of )
Velocity No
Xerces
ZooKeeper 68
PROJECT JIGSAW – INTEGRATION WITH TOOLS

69. HOW TO MODULARIZE A LIBRARY
Modularize the codebase by introducing a module-info.java file for each module
A module-info.java file can be:
1) Created manually by the developers
2) Automatically generated using the JDeps tool with the option --generate-module-info
The most common four issues that can occur during the modularization of a library are:
1) Encapsulated JDK internal APIs
3) Cyclic dependencies
2) Not resolved modules
4) Split packages 69
PROJECT JIGSAW – INTEGRATION WITH TOOLS

70. ENCAPSULATED JDK INTERNAL APIS
Most of the internal JDK APIs are inaccessible in Java 9
Trying to access them causes a compilation error
Internal APIs are in the sun.* package, but not only
The module jdk.unsupported is still accessible: sun.misc.Unsafe, sun.reflect.Reflection, sun.misc.Signal, sun.reflect.ReflectionFactory, sun.misc.SignalHandler 70
PROJECT JIGSAW – INTEGRATION WITH TOOLS

71. ENCAPSULATED JDK INTERNAL APIS
Breaking encapsulation of the JDK Internal APIs: 71
PROJECT JIGSAW – INTEGRATION WITH TOOLS

72. NOT RESOLVED PLATFORM MODULES
Not all the platform modules from the JDK are available at compile-time
All the packages from module java.se.ee are not available at compile-time: java.xml.ws, java.xml.bind, java.corba, java.activation, java.xml.ws.annotations => package not exist error encountered at compile-time 72
PROJECT JIGSAW – INTEGRATION WITH TOOLS

73. NOT RESOLVED PLATFORM MODULES
Solution: add the module that contains the needed packages in the graph of modules using the --add-modules options
--add-modules java.xml.bind
Use --add-modules both at compile-time and at run-time 73
PROJECT JIGSAW – INTEGRATION WITH TOOLS

74. CYCLIC DEPENDENCIES Forbidden at compile-time (between modules)
JPMS does not allow cycles in the “requires” clauses
JPMS allows cycles in the “reads” relation of run-time modules
module A {
requires B; }
module B {
requires A; } 74
PROJECT JIGSAW – INTEGRATION WITH TOOLS

75. CYCLIC DEPENDENCIES
One solution is to merge the JARs into a single module
Redesign might be necessary to a higher degree
Cycles can be broken by using interfaces 75
PROJECT JIGSAW – INTEGRATION WITH TOOLS

76. SPLIT PACKAGES
Modules that contain packages having the same name must not interfere with each other
Solutions for JAR files:
Create a single JAR file out of the two JAR files
Rename one of the package
Solutions for modules:
Create a single module out of two or more modules
Create a third module
Remove the package dependencies 76
PROJECT JIGSAW – INTEGRATION WITH TOOLS

77. Java 9 Modularity Revealed
Apress, 2017
221 pages
ISBN:

78. @alexandrujecan
alexandrujecan
alexandrujecan.com