Well, I just read Kohsuke's explanation about this, and running the
program in a forked Java process got things working. So it leaders me
to wonder if 1) the Maven plugin is using a separate classloader for
class and 2) what the delegation model is for that classloader. For
anyone who is interested here is the change I had to make to my
pom.xml.
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
...
<execution>
<id>exec</id>
<goals>
<goal>exec</goal>
</goals>
</execution>
</executions>
<configuration>
<executable>java</executable>
<arguments>
<argument>-classpath</argument>
<classpath/>
<argument>com.redhat.Main</argument>
</arguments>
</configuration>
</plugin>
On 6/19/06, John Sanda <john.sanda_at_gmail.com> wrote:
> I recently downloaded the JAXB 2.0.1 RI and started going through a
> couple of the samples. I came across the Maven plugin for xjc, and I
> decided to set up Maven builds for the samples, which I thought I
> might later post back to this list or the Maven users list. I
> apologize if I am posting on the wrong list, but I thought my
> question(s) might be better suited here as opposed to the Maven users
> list.
>
> I am having a problem in the create-marshal sample of the JAXB RI.
> When I try to run the program through Maven (using the exec plugin
> from mojo.codehaus.org), I get a LinkageError. Here is my pom.xml.
>
> <project xmlns="http://maven.apache.org/POM/4.0.0"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
> http://maven.apache.org/maven-v4_0_0.xsd">
> <modelVersion>4.0.0</modelVersion>
> <groupId>com.redhat</groupId>
> <artifactId>create-marshal</artifactId>
> <packaging>jar</packaging>
> <version>1.0-SNAPSHOT</version>
> <name>Maven Quick Start Archetype</name>
> <url>http://maven.apache.org</url>
>
> <repositories>
> <repository>
> <id>java.net</id>
> <name>java.net Maven Repository</name>
> <url>https://maven-repository.dev.java.net/nonav/repository</url>
> <layout>legacy</layout>
> <releases>
> <enabled>true</enabled>
> </releases>
> <snapshots>
> <enabled>true</enabled>
> </snapshots>
> </repository>
>
> <repository>
> <id>Maven Snapshots</id>
> <url>http://snapshots.maven.codehaus.org/maven2/</url>
> <snapshots>
> <enabled>true</enabled>
> </snapshots>
> <releases>
> <enabled>false</enabled>
> </releases>
> </repository>
> </repositories>
>
> <pluginRepositories>
> <pluginRepository>
> <id>Maven Snapshots</id>
> <url>http://snapshots.maven.codehaus.org/maven2/</url>
> <snapshots>
> <enabled>true</enabled>
> </snapshots>
> <releases>
> <enabled>false</enabled>
> </releases>
> </pluginRepository>
> </pluginRepositories>
>
> <dependencies>
> <dependency>
> <groupId>junit</groupId>
> <artifactId>junit</artifactId>
> <version>3.8.1</version>
> <scope>test</scope>
> </dependency>
>
> <!--
> <dependency>
> <groupId>javax.xml.bind</groupId>
> <artifactId>jaxb-api</artifactId>
> <version>2.0</version>
> <scope>compile</scope>
> </dependency>
> -->
>
> <dependency>
> <groupId>com.sun.xml.bind</groupId>
> <artifactId>jaxb-impl</artifactId>
> <version>2.0</version>
> <scope>compile</scope>
> </dependency>
> </dependencies>
>
> <build>
> <plugins>
> <plugin>
> <groupId>com.sun.tools.xjc.maven2</groupId>
> <artifactId>maven-jaxb-plugin</artifactId>
> <executions>
> <execution>
> <goals>
> <goal>generate</goal>
> </goals>
> </execution>
> </executions>
> <configuration>
> <schemaDirectory>src/main/resources/xsd</schemaDirectory>
> <generatePackage>primer.po</generatePackage>
> </configuration>
> </plugin>
>
> <plugin>
> <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.codehaus.mojo</groupId>
> <artifactId>exec-maven-plugin</artifactId>
> <executions>
> <execution>
> <goals>
> <goal>java</goal>
> </goals>
> </execution>
> </executions>
> <configuration>
> <mainClass>Main</mainClass>
> <systemProperties>
> <systemProperty>
> <key>dummyKey</key>
> <value>dummyValue</value>
> </systemProperty>
> </systemProperties>
> </configuration>
> </plugin>
> </plugins>
> </build>
> </project>
>
>
> I have the dependency for jaxb-api commented out since that dependency
> is satisfied by jaxb-impl, which I of course need to run the program.
> I should note that I have no problems generating the binding classes
> or compiling the source. To run Main, I issue the following at a
> command prompt
>
> mvn exec:java
>
> Here is a snippet from the stacktrace.
>
> Caused by: java.lang.LinkageError: loader constraints violated when
> linking javax/xml/namespace/QName class
> at com.sun.xml.bind.v2.model.impl.RuntimeBuiltinLeafInfoImpl.<clinit>(RuntimeBuiltinLeafInfoImpl.java:186)
> at com.sun.xml.bind.v2.model.impl.RuntimeTypeInfoSetImpl.<init>(RuntimeTypeInfoSetImpl.java:25)
> at com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.createTypeInfoSet(RuntimeModelBuilder.java:78)
> at com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.createTypeInfoSet(RuntimeModelBuilder.java:41)
> at com.sun.xml.bind.v2.model.impl.ModelBuilder.<init>(ModelBuilder.java:97)
> at com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.<init>(RuntimeModelBuilder.java:44)
> at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:343)
> at com.sun.xml.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:215)
> at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:76)
> at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:55)
> at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:124)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:585)
> at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:132)
> at javax.xml.bind.ContextFinder.find(ContextFinder.java:286)
> at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:372)
> at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:337)
> at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:244)
> at Main.main(Main.java:59)
>
> I know that JAXB 2 requires Java 5, and the LinkageError makes me
> think that somehow attempting to use classes compiled for an earlier
> release.
> --
>
> - John
>
--
- John