有关serviceloader的Java 9依赖性问题

我有一个问题，关于如何根据这种情况在Java 9中更改serviceloader

I have a question about how the serviceloader changed in Java 9 based on this scenario

项目 gert Class Main

package gert;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

public class Main { 
    static public void test() throws JAXBException {
        InputStream is = new ByteArrayInputStream("<Classes RUNTIME_INCLUDE_JARS=\"\"><Class></Class></Classes>".getBytes(StandardCharsets.UTF_8)); 
        JAXBContext jaxbContext = JAXBContext.newInstance(ClassesDef.class);
        Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
        unmarshaller.unmarshal(is);
    }
}

项目 gert Class ClassesDef

package gert;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Classes")
public class ClassesDef {
    @XmlAttribute(name="RUNTIME_INCLUDE_JARS")
    public String jars=null;

    @XmlElement(name="Class")
    public String classes;
}

项目 gert 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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>gert</groupId>
    <artifactId>gert</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <build>
        <sourceDirectory>src</sourceDirectory>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <mainClass>gert.Main</mainClass>
                        </manifest>
                    </archive>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency><!-- org.eclipse.persistence.jaxb.JAXBContextFactory comes with this dependency-->
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-moxy</artifactId>
            <version>2.26</version>
        </dependency>
    </dependencies>
</project>

项目 cristina Class 主要

package cristina;

import java.io.File;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.List;

public class Main {
    public static void main(String[] args) throws Exception {
        System.setProperty("javax.xml.bind.JAXBContextFactory", "org.eclipse.persistence.jaxb.JAXBContextFactory");
        String bWithDep = "C:\\Users\\gert\\eclipse-workspace91java\\gert\\target\\gert-0.0.1-SNAPSHOT-jar-with-dependencies.jar";
        List<URL> jars = new java.util.ArrayList<URL>();
        File f;
        f = new File(bWithDep);
        jars.add(f.toURL());
        URL[] urls = (URL[])jars.toArray(new URL[jars.size()]);
        URLClassLoader urlloader = URLClassLoader.newInstance(urls, ClassLoader.getSystemClassLoader());
        System.out.println("Before\tgert.Main.test();.");
        Class<?> c= Class.forName("gert.Main", true, urlloader);
        Object gert = c.newInstance();
        Method m = c.getMethod("test");
        m.invoke(gert);
        System.out.println("After\tgert.Main.test();.");
    }
}

项目 cristina 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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cristina</groupId>
  <artifactId>cristina</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.7.0</version>
        <configuration>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <dependencies>
    <!-- <dependency>
      <groupId>javax.xml.bind</groupId>
         <artifactId>jaxb-api</artifactId>
         <version>2.3.0</version>
      </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-moxy</artifactId>
        <version>2.26</version>
    </dependency> -->
  </dependencies>
</project>

所以cristina main 加载gert项目并执行gert方法名为 test（）

So the cristina main loads the gert project and executes a method of gert named test()

Java 8

当项目使用java 8运行时，它可以工作

Java 8
When the project is run with java 8 it works

Command

C：\Program Files\Java\jre1.8.0_151 \ bin\java.exe - cp C：\ Users\gert\eclipse-workspace91java\cristina\target\cristina-0.0.1-SNAPSHOT.jar cristina.Main

输出

在gert.Main.test（）;之前。
gert.Main.test（）;.


Java 9

完成同样的操作后java 9它没有

Before gert.Main.test();. After gert.Main.test();.
Java 9
When the same is done with java 9 it doesnt

命令

C ：\ Program Files\Java \jre-9.0.1 \bin\java.exe-cp C：\ Users\gert\eclipse-workspace91java\cristina\target\cristina-0.0 .1-SNAPSHOT.jar cristina.Main

输出

Before  gert.Main.test();.
Exception in thread "main" java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.base/java.lang.reflect.Method.invoke(Unknown Source)
        at cristina.Main.main(Main.java:23)
Caused by: javax.xml.bind.JAXBException: Implementation of JAXB-API has not been found on module path or classpath.
 - with linked exception:
[java.lang.ClassNotFoundException: org.eclipse.persistence.jaxb.JAXBContextFactory]
        at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:278)
        at javax.xml.bind.ContextFinder.find(ContextFinder.java:397)
        at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:721)
        at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:662)
        at gert.Main.test(Main.java:14)
        ... 5 more
Caused by: java.lang.ClassNotFoundException: org.eclipse.persistence.jaxb.JAXBContextFactory
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source)
        at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
        at javax.xml.bind.ServiceLoaderUtil.nullSafeLoadClass(ServiceLoaderUtil.java:122)
        at javax.xml.bind.ServiceLoaderUtil.safeLoadClass(ServiceLoaderUtil.java:155)
        at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:276)
        ... 9 more

以上2是直接从命令行完成的。

但是

当我取消注释 cristina 项目的 pom.xml 中的依赖项时，我会进行maven安装和从eclipse运行项目，java 9可以正常工作。因此，在运行项目时，eclipse似乎也会考虑maven依赖关系。

The 2 above are done directly from the command line.
BUT
When I uncomment the dependencies in the pom.xml of the cristina project and I do a maven install and run the project from eclipse, java 9 works. So it seems that eclipse also takes the maven dependencies into consideration when running a project.

当依赖项在 gert 项目中，仅由 gert 项目使用，为什么 cristina 项目在使用Java 9运行时抛出异常？

When the dependencies are in the gert project and only used by the gert project why does the cristina project throw an exception when running it with Java 9?