JDK support for VM to read classes from modules in a module library

[Jesse Glick]

On 05/16/2012 01:42 PM, Alan Bateman wrote:
> [...In Properties] the workaround is to use the loader for the base module to load
> XMLUtils. Given that XMLUtil is currently in the jaxp module (and I know this isn't quite right either as JAXP is a standalone technology etc.) then I would think that
> the Properties code will need to do a Class.forName on an exported javax.xml type and use that loader (or alternative use jdk.jaxp).

You have a module system now, why not clean this up and get rid of the reflection (and cyclic dependency)?

module jdk.base {
   ...
   view sun.jaxp.bridge {
     permits jdk.jaxp;
     export sun.misc;
   }
   requires optional service sun.misc.XMLUtils;
}
package sun.misc;
public interface XMLUtils {
   void load(Properties props, InputStream in) throws IOException, InvalidPropertiesFormatException;
   void save(Properties props, OutputStream os, String comment, String encoding) throws IOException;
}
package java.util;
public class Properties {
   ...
   @RequireOptionalModule("jdk.jaxp")
   public synchronized void loadFromXML(InputStream in) throws IOException, InvalidPropertiesFormatException {
     try {
       ServiceLoader.loadInstalled(XMLUtils.class).iterator().next().load(this, in);
     } catch (NoSuchElementException x) {
       throw new ModuleNotPresentException("jdk.jaxp missing", x);
     }
   }
   @RequireOptionalModule("jdk.jaxp")
   public void storeToXML(OutputStream os, String comment, String encoding) throws IOException {
     try {
       ServiceLoader.loadInstalled(XMLUtils.class).iterator().next().save(this, os, comment, encoding);
     } catch (NoSuchElementException x) {
       throw new ModuleNotPresentException("jdk.jaxp missing", x);
     }
   }
}
module jdk.jaxp {
   ...
   requires sun.jaxp.bridge;
   provides service sun.misc.XMLUtils with ...;
}