dragoman

Prerequisites

Install Java 10 JDK

The following instructions all relate to MacOs.

$ brew update
$ brew tap caskroom/cask
$ brew tap caskroom/versions
$ brew cask info java
# this is valid as long as the current version of java is 10, if not you may have to specify java10
$ brew cask install java

Check the installations:

$ ls /Library/Java/JavaVirtualMachines/
jdk-10.0.2.jdk/  jdk1.8.0_51.jdk/

For help with running multiple versions of Java on MacOs:

• Install jenv: brew install jenv
• Add the following lines to ~/.bash_profile to initialize jenv:

  # Init jenv
  if which jenv > /dev/null; then eval "$(jenv init -)"; fi
  

• Tell jenv about the installed JDKs:

  jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_51.jdk/Contents/Home/
  jenv add /Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/
  

• Check that the JDKs have been registered: jenv versions, the output will be something like the following (the asterix marks the active version):

  $ jenv versions
    system
    1.8
    1.8.0.51
    10.0
    10.0.2
  * oracle64-1.8.0.51
    oracle64-10.0.2
  

• Set the default JDK to 1.8: jenv global oracle64-1.8.0.51
• Set the project specific JDK to 10: cd dragoman; jenv global oracle64-10.0.2

IDE

If using Intellij, upgrade to 2018.1+ and reconfigure the dragoman project to use Java 10:

• Module Settings > Platform Settings > ``SDKs> Add a new SDK pointing at/Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/`
• Module Settings > Project Settings > Project SDK: 10
• Module Settings > Project Settings > Project Language Level: 10

Compile the Application With Java 10

This makes Java 10 features avaialble to the application but it requires some changes:

• Tell Maven to build with Java 10 and to target Java 10 output
• Upgrade some internal dependencies to Java 10 compatible versions

Required Changes to dragoman

• Change maven.compiler.source to 1.10
• Change maven.compiler.target to 1.10
• Upgrade Maven Compiler Plugin:

  <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.8.0</version>
      <configuration>
          <release>10</release>
      </configuration>
  </plugin>
  

• Add a dependency on org.ow2.asm:asm:6.1.1 to the maven-surefire-plugin declaration:

  <dependency>
      <groupId>org.ow2.asm</groupId>
      <artifactId>asm</artifactId>
      <version>6.1.1</version>
  </dependency>
  

• Upgrade Mockito for compatability with Java 10: change mockito.version to 2.21.0
• Upgrade Jacoco for compatability with Java 10: change maven.jacoco.plugin.version to 0.8.1
• Tell Travis CI to build with Java 10, in .travis.yml:

  jdk:
    - oraclejdk10
  

Optional Changes to dragoman

• Upgrade de.flapdoodle.embed.mongo to 2.1.1, see this issue
• Update GroovyFactory to replace the deprecated clazz.newInstance() with clazz.getConstructor().newInstance()

Modularize the Application

This uses Java 10's module system.

Add a file named module-info.java to src/main/java with the following content:

module io.github.glytching {
    requires antlr4;
    requires bson;
    requires guava;
    requires vertx.core;
    requires vertx.web;
    requires vertx.dropwizard.metrics;
    requires slf4j.api;
    requires rxjava;
    requires org.apache.commons.lang3;
    requires javax.inject;
    requires mongodb.driver.rx;
    requires jackson.databind;
    requires guice;
    requires guice.multibindings;
    requires jolokia.jvm;
    requires de.flapdoodle.embed.mongo;
    requires de.flapdoodle.embed.process;
    requires mongodb.driver.core;
    requires mongodb.driver.async;
    requires netty.codec;
    requires netty.handler;
    requires metrics.core;
    requires metrics.healthchecks;
    requires okhttp;
    requires commons.validator;
    requires handlebars;
    requires constretto.api;
    requires constretto.core;
    requires org.apache.commons.io;
}

Compile the project and you'll encounter the 'split package' issue (two members of the same package coming from different modules):

[ERROR] the unnamed module reads package org.constretto from both constretto.api and constretto.core
[ERROR] the unnamed module reads package org.constretto.model from both constretto.api and constretto.core
[ERROR] module constretto.api reads package org.constretto from both constretto.api and constretto.core
[ERROR] module constretto.api reads package org.constretto.model from both constretto.api and constretto.core
[ERROR] module handlebars reads package org.constretto from both constretto.api and constretto.core
[ERROR] module handlebars reads package org.constretto.model from both constretto.api and constretto.core

Stop, because ...

• The libraries used by this project which manifest the 'split package' issue are not in our control
• This project isn't a strong candidate for modularisation. This might change if the webapp is separated from the library.