Support java 9 projects

[RyanBard]

When #259 was fixed, it only verified that jjwt itself can be built with Java 9 (but targeting an older version of java). It did not address the problem of using jjwt in a project that is targeting Java 9.

You can see the problem in jjwt by modifying the <jdk.version> to 1.9 and trying to build:

diff --git a/pom.xml b/pom.xml
index 1c34c5b..02e3f5a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -81,7 +81,7 @@
         <maven.jar.version>3.0.2</maven.jar.version>
         <maven.compiler.version>3.6.1</maven.compiler.version>
 
-        <jdk.version>1.7</jdk.version>
+        <jdk.version>1.9</jdk.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <buildNumber>${user.name}-${maven.build.timestamp}</buildNumber>
 

Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T03:58:13-04:00)
Maven home: /Users/ryan/.m2/wrapper/dists/apache-maven-3.5.2-bin/28qa8v9e2mq69covern8vmdkj0/apache-maven-3.5.2
Java version: 9.0.1, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk/Contents/Home
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.13.1", arch: "x86_64", family: "mac"

[INFO] --- maven-compiler-plugin:3.6.1:compile (default-compile) @ jjwt ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 81 source files to /Users/ryan/projects/java/jjwt/target/classes
[INFO] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/lang/Classes.java: Some input files use or override a deprecated API.
[INFO] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/lang/Classes.java: Recompile with -Xlint:deprecation for details.
[INFO] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/lang/RuntimeEnvironment.java: Some input files use unchecked or unsafe operations.
[INFO] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/lang/RuntimeEnvironment.java: Recompile with -Xlint:unchecked for details.
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/impl/Base64Codec.java:[21,25] package javax.xml.bind is not visible
  (package javax.xml.bind is declared in module java.xml.bind, which is not in the module graph)
[ERROR] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/impl/Base64Codec.java:[26,25] package javax.xml.bind is not visible
  (package javax.xml.bind is declared in module java.xml.bind, which is not in the module graph)
[INFO] 2 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.205 s
[INFO] Finished at: 2017-11-18T14:57:44-05:00
[INFO] Final Memory: 26M/86M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:compile (default-compile) on project jjwt: Compilation failure: Compilation failure: 
[ERROR] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/impl/Base64Codec.java:[21,25] package javax.xml.bind is not visible
[ERROR]   (package javax.xml.bind is declared in module java.xml.bind, which is not in the module graph)
[ERROR] /Users/ryan/projects/java/jjwt/src/main/java/io/jsonwebtoken/impl/Base64Codec.java:[26,25] package javax.xml.bind is not visible
[ERROR]   (package javax.xml.bind is declared in module java.xml.bind, which is not in the module graph)
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

I have also created a project that uses jjwt and shows the problem referenced in #259: https://github.com/RyanBard/jjwt-consumer-example

The problem is that Java 9 has deprecated jaxb and it requires extra flags to include that module. If I understand correctly, jaxb will probably be completely removed in Java 10, so it seems like the best solution is to explicitly depend on jaxb. This should make it easier for jjwt to target multiple versions of java without having to build multiple artifacts with different classifiers.

[Spenhouet]

I can't build my project because of this issue.

[RyanBard]

@Spenhouet

You can add an explicit dependency on jaxb-api to your project until jjwt adds the dependency or removes the usage of jaxb classes:

https://github.com/jwtk/jjwt/pull/283/files

[househacker]

Any advice on how to configure this same workaround for a Java 9 proejct built with ant?
I have tried the --add-modules java.xml.bind

[Spenhouet]

When will the commit from @RyanBard be merged and when will there be a Java 9 compatible release?

[RyanBard]

@househacker, I haven't used ant in a long time, but I assume you can just specify the dependency information from maven (groupId=javax.xml.bind, artifactId=jaxb-api, version=2.3.0) if you use something like ivy.

Otherwise, you can download the jar out of the maven repo and include it in your projects' lib dir or something:

• https://repo1.maven.org/maven2/javax/xml/bind/jaxb-api/2.3.0/jaxb-api-2.3.0.jar

[househacker]

Thanks, I had success with the brute force setting: --add-modules java.se.ee

<target name="compile" depends="jooq">
    <echo>Compiling source code with:</echo>
    <echo>Java/JVM detail version: ${java.version}</echo>
    <javac executable="/Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk/Contents/Home/bin/javac" srcdir="${basedir}/src" destdir="${build}/classes" listfiles="yes" debug="true"
           debuglevel="lines,vars,source">
        <compilerarg line="--add-modules java.se.ee" />
        <classpath>
            <path refid="compile.classpath"/>
        </classpath>
        <include name="**/*.java"/>
    </javac>
</target>

[lhazlewood]

@RyanBard thanks for your help/input in this. The JAXB import was provided only because that was guaranteed to work in JDK 7 and 8 environments using the same code. The real solution to this problem is basically to detect if using JDK 8 and above, and if so, use the JDK's native Base64 encoder/decoder, and if on JDK 7, use the JAXB APIs. That said, we probably won't support JDK 7 for too much longer.

[lhazlewood]

@RyanBard I think we need to modify https://github.com/jwtk/jjwt/blob/master/src/main/java/io/jsonwebtoken/impl/DefaultTextCodecFactory.java to check for the presence of java.util.Base64, and if available, use that. It's available on later Android SDKs as well as JDK 8.

We'll still need to fall back to either the previous native Android codec or the JAXB api depending on if java.util.Base64 is not available and depending on the runtime environment.

[RyanBard]

I'll try that out some time tonight.

[lhazlewood]

Closing as a duplicate of #333. Work will be tracked via that issue and we hope to have that released asap in the coming days.