Difference of Maven JAXB plugins - java

I have determined that two JAXB plugins for Maven 2 exist, with some different configurations.
The one is from Sun: http://jaxb.dev.java.net/jaxb-maven2-plugin/, the other from Mojohaus: http://mojohaus.org/jaxb2-maven-plugin/
Which of these two plugins can be recommended?
Thanks Matt. On my little research project, I found that there's quite another plugin comming from the sunners:
<groupId>com.sun.tools.xjc.maven2</groupId>
<artifactId>maven-jaxb-plugin</artifactId>
and that one:
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
and still the one from Codehouse.

Let's summarize. We have/had:
the maven-jaxb2-plugin (https://github.com/highsource/maven-jaxb2-plugin)
the maven-jaxb-plugin (https://jaxb.dev.java.net/jaxb-maven2-plugin/)
the jaxb2-maven-plugin (https://github.com/mojohaus/jaxb2-maven-plugin)
Based on the comments of this thread, I've always used the maven-jaxb2-plugin (i.e. plugin #1):
Concerning the
org.jvnet.jaxb2.maven2:maven-jaxb2-plugin
versus
com.sun.tools.xjc.maven2:maven-jaxb-plugin,
from my point of view it's definitely
the first one
(http://maven-jaxb2-plugin.java.net/).
This plugin has much more features
than
com.sun.tools.xjc.maven2:maven-jaxb-plugin,
the development is active. Finally,
I'm one of the authors :) and I'd say
we keep in touch with JAXB developers
and users and react to the latests
features/requests.
And indeed, the plugin #2 is dead. And because I've always been happy with #1, I've never used plugin #3 so can't really say anything about it. Just in case, here is a working configuration for plugin #1:
<project>
...
<build>
<plugins>
<plugin>
<inherited>true</inherited>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>
<plugin>
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

I have recently tried the three plug-ins mentioned above (included here as well):
the maven-jaxb2-plugin (http://maven-jaxb2-plugin.java.net/)
the maven-jaxb-plugin (https://jaxb.dev.java.net/jaxb-maven2-plugin/)
the jaxb2-maven-plugin (http://mojo.codehaus.org/jaxb2-maven-plugin/)
I ended up using a fourth option: The CXF XJC Maven Plugin http://cxf.apache.org/cxf-xjc-plugin.html
If I am missing something I would like to know, but the configuration seemed more straightforward for what I was trying to do and more easily allowed me to to deal with duplicate class generation within the same namespace -- similar to this question: Is there a way to deal with duplicate element definitions across multiple .xsd files in JAXB?.
I now have granular control over each incoming XSD and corresponding java package; here is a sample configuration close to the one I am using.
<plugin>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-xjc-plugin</artifactId>
<version>2.3.0</version>
<configuration>
<extensions>
<extension>org.apache.cxf.xjcplugins:cxf-xjc-dv:2.3.0</extension>
</extensions>
</configuration>
<executions>
<execution>
<id>generate-sources</id>
<phase>generate-sources</phase>
<goals>
<goal>xsdtojava</goal>
</goals>
<configuration>
<sourceRoot>${basedir}/target/generated-sources/src/main/java</sourceRoot>
<xsdOptions>
<xsdOption>
<xsd>src/main/resources/schema/commands.xsd</xsd> <!--shares a common.xsd file causing the conflicts-->
<packagename>com.foo.bar.commands</packagename>
</xsdOption>
<xsdOption>
<xsd>src/main/resources/schema/responses.xsd</xsd>
<packagename>com.foo.bar.responses</packagename>
</xsdOption>
</xsdOptions>
</configuration>
</execution>
</executions>
</plugin>

I am the author of maven-jaxb2-plugin.
The maven-jaxb2-plugin currently uses JAXB 2.1. In the next versions we'll also provide JAXB 2.0 and JAXB 2.2 versions.
As for "which plugin is better" discussion, check the features, decide yourself. Let me know if you miss some functionality.

maven-jaxb2-plugin uses the JAXB reference implementation by Oracle/Sun
cxf and jaxb2-maven-plugin use Apache Xerces

On a slight tangent: there was a problem with use of maven-jaxb2-plugin with Eclipse Indigo that I posted here. A fix (extension) has recently become available.
This is not meant to disagree, at all, with the recommendation of maven-jaxb2-plugin over maven2-jaxb-plugin. I don't know, but I expect that maven2-jaxb-plugin has the same problem, probably unresolved.

I would guess that one is for the original JAXB specification and the codehaus one is for the JAXB 2.1 specification (and if the dev.java.net would load some time this century, I'd be able to say for sure).

Related

Is there a maven jigsaw jlink plugin?

Does maven have a plugin for the new Java 9 jlink I have searched online but have not been able to find anything official from the maven team.
Yes. There has been some progress made to create one on Github/maven-plugins for the same.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jlink-plugin</artifactId>
<version>3.0.0-SNAPSHOT</version>
</plugin>
The plugin in its code reads to be adaptive to JEP-282 and JEP-220 from the proposals.
And though this might look like a link too many answer. There is a working example from #khmarbaise on Github as well for this, which requires a toolchain with -
<configuration>
<jdkHome>/Library/Java/JavaVirtualMachines/jdk1.9.0_ea+170.jdk/Contents/Home</jdkHome>
</configuration>
Plus a side note from the author quoting -
Currently not more than a Proof of Concept. Everything here is speculative!
Edit1:- As shared in the comments, additional details could be found # How to create a Java runtime with Maven.
Edit2:- Dated 10 November, 2018 one can upgrade to using maven-jlink-plugin:3.0.0-alpha-1 and still provide some valuable feedback.
I'm working on ModiTect, general tooling around Java 9 modules. One of the goals of the ModiTect Maven plug-in lets you create module runtime images via jlink:
<plugin>
<groupId>org.moditect</groupId>
<artifactId>moditect-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
<executions>
<execution>
<id>create-runtime-image</id>
<phase>package</phase>
<goals>
<goal>create-runtime-image</goal>
</goals>
<configuration>
<modulePath>
<path>${project.build.directory}/modules</path>
</modulePath>
<modules>
<module>com.example.module1</module>
<module>com.example.module2</module>
</modules>
<launcher>
<name>helloWorld</name>
<module>com.example.module1</module>
</launcher>
<outputDirectory>
${project.build.directory}/jlink-image
</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
The plug-in is under active development right now and must be built from source for the time being (will deploy a first version to Maven Central soon).
there is mvn-jlink plugin which allows to call jdeps and jlink (and any tool provided by jdk), also it can download and unpack needed openjdk version from ADOPT and LIBERICA, such way allows build cross-platform images
<plugin>
<groupId>com.igormaznitsa</groupId>
<artifactId>mvn-jlink-wrapper</artifactId>
<version>1.0.0</version>
<executions>
<execution>
<id>call-jlink</id>
<goals>
<goal>jlink</goal>
</goals>
<configuration>
<jdepsReportPath>${project.build.directory}${file.separator}jdeps.out</jdepsReportPath>
<output>${project.build.directory}${file.separator}preparedJDK</output>
<addModules>
<module>java.compiler</module>
</addModules>
<options>
<option>--compress=2</option>
<option>--no-header-files</option>
<option>--no-man-pages</option>
</options>
</configuration>
</execution>
</executions>
</plugin>
Maybe check out https://github.com/ghackenberg/jigsaw-maven-plugin. The plugin also supports
jdeps --generate-module-info + javac + jar for patching unnamed modules,
jlink for creating runtime images, and
jpackage for creating application installers (only available since JDK 14 though).
You find the plugin documentation on the Github README page.
<plugin>
<groupId>io.github.ghackenberg</groupId>
<artifactId>jigsaw-maven-plugin</artifactId>
<version>1.1.3</version>
</plugin>

Two maven versions required in pom.xml - what to do?

I'm trying to build JavaOCR project with mvn clean install. There is used maven-enforcer-plugin in the pom.xml and there are two required Maven versions. (Or maybe I misunderstood something)
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-enforcer-plugin</artifactId>
<version>1.4</version>
<executions>
<execution>
<id>enforce-versions</id>
<goals>
<goal>enforce</goal>
</goals>
<configuration>
<rules>
<requireMavenVersion>
<!--different rules for different issues-->
<!--3.3.x causes `java.lang.NoClassDefFoundError: org/eclipse/aether/spi/connector/Transfer$State` which is caused by certain maven versions, see https://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound for details-->
<version>(,3.3)</version>
<!--3.2.x causes `No implementation for org.eclipse.aether.connector.wagon.WagonConfigurator was bound.`-->
<version>(,3.2)</version>
</requireMavenVersion>
</rules>
</configuration>
</execution>
</executions>
</plugin>
Currently I have installed maven 3.3.3 and it throws the java.lang.NoClassDefFoundError error (same as described in the comment in pom.xml), so I cannot build it.
My question is what version should I use to build the project successfully? Is it possible to use two maven versions simultaneously?
According to Maven's Version Range Specification documentation, that's specifying a range, not a specific version. (,3.2) means anything less than version 3.2, so those two configurations are compatible: for example, use version 3.1.
This is reinforced by the comments in the pom file, which say that versions 3.2.x and 3.3.x cause errors, so don't use them.
See also
Version Range Specification

How can I generate classes from outside XSD file using JAXB XJC

I have two projects:
A
/src/main/resources/schema.xsd
pom.xml
B
/src/main/gen
pom.xml
I want in B project generate classes from XSD, that exists in A Project
In pom.xml of B project I have:
<dependencies>
<dependency>
<groupId>test</groupId>
<artifactId>A</artifactId>
<version>${project.version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>jaxb2-maven-plugin</artifactId>
<executions>
<execution>
<id>xjc</id>
<goals>
<goal>xjc</goal>
</goals>
</execution>
</executions>
<configuration>
<schemaDirectory>src/main/resources</schemaDirectory>
<outputDirectory>src/main/gen</outputDirectory>
</configuration>
</plugin>
</plugins>
</build>
But xsd file is not found in classpath:
Failed to execute goal org.codehaus.mojo:jaxb2-maven-plugin:1.5:xjc (xjc) on project B: No schemas have been found
How can I use xsd from another project?
My maven-jaxb2-plugin supports separate schema compilation.
How to do this:
Add your artifact a as episode.
If a.xsd is imported into b.xsd, you have to make this schema available to JAXB when compiling b:
One way to do this is to extract a.xsd from the artifact a using Maven dependency plugin, for instance.
Another way would be to use a catalog file to rewrite the location of a.xsd into the artifact a
See this test project for example.
The project a is totally unspectacular. Just compiles the schema a.xsd.
The project b is more interesting. Let's take a look.
pom.xml:
<plugin>
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
<configuration>
<catalog>src/main/resources/catalog.cat</catalog>
<episodes>
<episode>
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin-tests-MAVEN_JAXB2_PLUGIN-82-a</artifactId>
</episode>
</episodes>
</configuration>
</plugin>
The configuration says use the artifact a as episode. So when JAXB/XJC meets classes compiled in a, it will reuse them instead of generating new ones.
By the way, you can use the useDependenciesAsEpisodes instead of configuring individual episodes. In this case all the dependencies will be treated as episodes which is very convenient (less configuration).
The configuration also says to use the catalog file:
REWRITE_SYSTEM "http://www.ab.org" "maven:org.jvnet.jaxb2.maven2:maven-jaxb2-plugin-tests-MAVEN_JAXB2_PLUGIN-82-a:jar::!"
This instructs JAXB/XJC to rewrite all schema URLs starting with http://www.ab.org to start with maven:org.jvnet.jaxb2.maven2:maven-jaxb2-plugin-tests-MAVEN_JAXB2_PLUGIN-82-a:jar::! instead. The latter will be processed by the maven-jaxb2-plugin and finally resolved to the resource in a.
Let's take a closer look. The schema b.xsd imports http://www.ab.org/a.xsd:
<import namespace="urn:a" schemaLocation="http://www.ab.org/a.xsd"/>
This will be rewritten to maven:org.jvnet.jaxb2.maven2:maven-jaxb2-plugin-tests-MAVEN_JAXB2_PLUGIN-82-a:jar::!/a.xsd which will be resolved to the a.xsd inside the JAR of the project a. So, finally, JAXB/XJC will be able to read this schema from the a's JAR artifact.
You can also use PUBLIC instead of REWRITE_SYSTEM to reference a.xsd per namespace URI instead of schema location (which is logically better):
PUBLIC "urn:a" "maven:org.jvnet.jaxb2.maven2:maven-jaxb2-plugin-tests-MAVEN_JAXB2_PLUGIN-82-a:jar::!/a.xsd"
However there's a bug in JAXB/XJC this does not work if you have schemaLocation in your xs:import.
This would work at the moment:
<xsd:import namespace="urn:a"/>
This won't work at the moment:
<xsd:import namespace="urn:a" schemaLocation="a.xsd"/>
I've sent Oracle a pull request which fixes that but it's not applied yet.
The explanation above applies to the maven-jaxb2-plugin and works in versions 0.10.0 and higher.
Your original question is about jaxb2-maven-plugin from Codehaus which is a different Maven plugin. This plugin does not have all the features I've described above, but at least episodes should work via arguments. Catalogs must also work, but I believe, jaxb2-maven-plugin does not support resolving schemas in Maven artifacts. You can use the maven-dependency-plugin to extract a.xsd from artifact a instead.
SO disclaimer: I am the author of the maven-jaxb2-plugin.
Note for reviewers: it is NOT my intention here to push/advertise my plugin, I just want to provide a solution to the asked question. And it appears that my project offers the best/most elegant and full solution.
The problem with this configuration is that <schemaDirectory> expects a File name/path. The thing about File is that it looks for files on the file system, searching from the current working directory. In which case the project root. But the resource from project A is not in the src/main/resources of the project B. It is a classpath resource, of which (when build in maven), the src/main/resources doesn't even exist anymore.
I've never tried to do with with the jaxb2-maven-plugin, so I am not sure if it is possible.
But with the maven-jaxb2-plugin, it allows Compiling a schema from a Maven artifact. You could so something like
<plugin>
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
<version>0.9.0</version>
<executions>
<execution>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
<configuration>
<schemas>
<schema>
<dependencyResource>
<groupId>projecta.groupid</groupId>
<artifactId>project-a</artifactId>
<version>${project.version}</version>
<resource>/schema.xsd</resource>
</dependencyResource>
</schema>
</schemas>
<generateDirectory>src/main/gen/</generateDirectory>
<generatePackage>mypackage</generatePackage>
</configuration>
</plugin>
In which case, it's resource (schema.xsd) is in the src/main/resources of project A. The plugin will generate the class files to the mypackage package and sources the src/main/gen
We can also use as below in pom.xml file
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>jaxb2-maven-plugin</artifactId>
<version>1.5</version>
<executions>
<execution>
<id>id1</id>
<goals>
<goal>xjc</goal>
</goals>
<configuration>
<outputDirectory>src/main/java</outputDirectory>
<clearOutputDir>false</clearOutputDir>
<packageName>com.subu.xsd.model</packageName>
<schemaDirectory>src/main/java/schemadir</schemaDirectory>
<schemaFiles>XYZ.xsd</schemaFiles>
</configuration>
</execution>
</executions>
</plugin>

Unable to generate JAXB artifacts due to WSDL import

I am having a WSDL (lets say one.wsdl ) from which I want to generate JAXB artifacts using maven plugin. one.wsdl imports another wsdl (two.wsdl ) . When I am running the maven plugin to generate the JAXB artifacts , looks like its not recognizing two.wsdl and not generating the JAXB artifacts.
<plugin>
<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
<version>0.7.5</version>
<executions>
<execution>
<id>DataBindings_XJC_generate</id>
<goals>
<goal>generate</goal>
</goals>
<configuration>
<schemaDirectory>src/main/resources/wsdl/</schemaDirectory>
<schemaIncludes>
<include>one.wsdl</include>
</schemaIncludes>
<generateDirectory>src/main/java/</generateDirectory>
<generatePackage></generatePackage>
<readOnly>true</readOnly>
<removeOldOutput>true</removeOldOutput>
<verbose>true</verbose>
<extension>false</extension>
<forceRegenerate>true</forceRegenerate>
<episode>false</episode>
</configuration>
</execution>
</executions>
</plugin>
one.wsdl is refering to two.wsdl like this (both are in same directory).
<wsdl:import namespace="http://namespce:uri" location="two.wsdl"/>
However If i give the two.wsdl (in the include tag) in plugin , its able to generate the jaxb artifacts successfully.
Can anyone please suggest what might have gone wrong with the plugin when it comes to recognizing the imported WSDL ?
maven-jaxb2-plugin is just a wrapper for XJC. It does not do any schema processing on it own, it just calls XJC.
Please send me a test case as a PR request here:
https://github.com/highsource/maven-jaxb2-plugin/tree/master/tests
I'll check if this has something to do with the plugin (unlikely) or forward it to Oracle.
I think, this might be also by design - if your one.wsdl does not use anything from two.wsdl then nothing for the two.wsdl will be generated.

Can maven change package declarations when compiling a project?

Well, I have googled this topic many times and I haven't found an answer yet: Can maven change the package declarations right before compiling a project?
My objective is have project A, which is an API, all in one package, and each project B and C will use the same dependency on eclipse. My objective is that once maven is about to compile the project, the package declarations get changed to that project's specific package and then it compiles the project.
This is useful because I have many projects using the same API and I keep making changes to the API itself to suit my needs, but it's a pain to have to go trough every project and change it all again.
If you have any idea how to do this, and, more importantly, if it is possible, let me know please. Thanks in advance!
Google's maven replacer plugin can do such things, it can edit your java files at build time. I have used it for silencing warnings in automatically generated java files. It can definitely be used for even more evil things.
<plugin>
<groupId>com.google.code.maven-replacer-plugin</groupId>
<artifactId>maven-replacer-plugin</artifactId>
<version>1.3.2</version>
<executions>
<execution>
<phase>generate-sources</phase>
<goals>
<goal>replace</goal>
</goals>
</execution>
</executions>
<configuration>
<includes>
<include>src/main/java/mycodegen/**/*.java</include>
</includes>
<regex>true</regex>
<regexFlags>
<regexFlag>MULTILINE</regexFlag>
</regexFlags>
<replacements>
<replacement>
<token>^public class</token>
<value>#SuppressWarnings("all") public class</value>
</replacement>
</replacements>
</configuration>
</plugin>
This is what I had used. It should be very similar to change package declarations in Java files. By now there should be much newer versions of the plugin.

Categories

Resources