Migrating to Java 11 / Servlet 4.0

Migrating to Java 11 / Servlet 4.0#

From version 3.0.0, Igloo is now build with Java 11. Igloo also uses API Servlet version 4.0 and it will lead to encoding character issues. Here are some vigilance points to be aware of.

Servlet Version#

Before version 4.0, the character encoding was set by default. Now, it can be customised ; but it needs to be specified manually. If a character encoding is not specified, the Servlet specification requires that an encoding of ISO-8859-1 is used.

To use UTF-8 in your project :

  • Update the xsi:schemaLocation and the version in web.xml :

    <web-app xmlns="http://java.sun.com/xml/ns/j2ee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_4_0.xsd"
  version="4.0" metadata-complete="true">

  • Add character encoding in web.xml :

    <request-character-encoding>UTF-8</request-character-encoding>
<response-character-encoding>UTF-8</response-character-encoding>

Java Version#

Java 11+ is mandatory for building and running Igloo projects. Update :

  • Your IDE setting

  • Your Tomcat configuration (Tomcat 9 required) to run with Java 11

  • Your maven setting (JAVA_HOME=/usr/lib/jvm/java-11/ mvn)

  • Your runtime environment (ensure JAVA_HOME environment setting for your tomcat runtime)

  • Your CI settings (JAVA_HOME, docker image, …)

Update your project#

  • Update parent pom version

  • Update igloo.version property

  • fix broken imports

    • fix wrong imports of jersey.repackaged replaced with com.google...

    • de.schlichtherle/TFile replaced with net.java.truevfs...

  • optional - Apache POI: remove setCellType calls (setCellValue automatically override type)

  • optional - Java: replace Class.newInstance() by Class.getConstructor().newInstance() and add InvocationTargetException | NoSuchMethodException | IllegalArgumentException to the existing catch block

  • replace lifecycle-mapping maven plugin configuration (used to control how eclipse maps maven plugin lifecycle to eclipse build) by <?m2e ...> XML processing instruction (see https://www.eclipse.org/m2e/documentation/release-notes-17.html#new-syntax-for-specifying-lifecycle-mapping-metadata) This instruction may be added at <plugin> or <execution> level

Maven plugins#

Compiler and processor plugin uses --release option to force java 11 usage. Check you do not override these setttings.

Dependencies#

Several dependencies have been updated to Java 11-mandatory versions :

  • bindgen : expected >= 5.0.0

  • bindgen-bindings-java : expected >= 2.0.0

  • bindgen-java : expected >= 2.0.0

  • maven-processor-plugin : expected >= 4.4

  • jersey : expected >= 2.32

  • querydsl : expected >= 5.0.0

Be careful with these if you have one of them in a custom version.

Jersey#

Jersey has been updated from jersey-spring3 to jersey-spring5. This update had several effects :

  • Jersey do not longer repackage guava, so you have to refactor your jersey.repackaged imports if you have some and directly import guava.

  • Due to some version conflicts with jackson-module-jaxb-annotations and hk2-utils/runlevel, jakarta-xml-bind-api, jakarta-activation-api and jakarta-annotation-api versions are now manually declared.

javax.annotations#

From Java 9, javax.annotation is reworked.

  • javax.annotation linked to injection management (@PostConstruct, @Managed) are moved in an external dependency, javax.annotation:javax.annotation-api. In Igloo context, this dependency is used when Spring beans are managed via javax.annotation annotations.

  • JSR 305 javax.annotation are removed (@Nonnull, …); we use instead com.google.code.findbugs:jsr305 dependency.

  • javax.annotation.Generated is replaced by runtime-provided javax.annotation.processing.Generated (updated bindgen version, querydsl 5.0.0 with custom configuration).

In your projects :

  • If you encounter spring initialization problems with missing Spring beans, add a scope-provided javax.annotation:javax.annotation-api dependency (this dependency is provided by tomcat container).

  • If you have javax.annotation.Generated references, regenerate code or search for an updated and javax.annotation.processing.Generated-friendly dependency.