java.net.MalformedURLException: unknown protocol: dummy异常

JBoss中，启动Applet连接EJB，出现java.net.MalformedURLException: unknown protocol: dummy异常

（其实还有一个Log4j的异常：

[java] log4j:WARN No appenders could be found for logger (org.jboss.security.SecurityAssociation).
[java] log4j:WARN Please initialize the log4j system properly.
）

解决：

查找您系统下是否有一个gnujaxp.jar文件，并删除它。

The gnujaxp.jar file is most easily installed in $JAVA_HOME/jre/lib/ext; otherwise you may prefer to modify your CLASSPATH. If you have other JAXP parsers installed you may also wish to set up $JAVA_HOME/jre/lib/jaxp.properties so the GNU JAXP drivers are used by default:

# make JAXP clients prefer the GNU implementations
javax.xml.parsers.SAXParserFactory=gnu.xml.aelfred2.JAXPFactory
javax.xml.parsers.DocumentBuilderFactory=gnu.xml.dom.DomDocumentBuilderFactory
javax.xml.transform.TransformerFactory=gnu.xml.transform.TransformerFactoryImpl
javax.xml.xpath.XPathFactory=gnu.xml.xpath.XPathFactoryImpl
Alternatively, you may specify the use of the experimental libxmlj implementations, as follows:

javax.xml.parsers.SAXParserFactory=gnu.xml.libxmlj.sax.GnomeSAXParserFactory
javax.xml.parsers.DocumentBuilderFactory=gnu.xml.libxmlj.dom.GnomeDocumentBuilderFactory
javax.xml.transform.TransformerFactory=gnu.xml.libxmlj.transform.GnomeTransformerFactory
If you are using the portable SAX2 bootstrapping APIs, you may want to set the org.xml.sax.driver system property on each JVM invocation to be gnu.xml.aelfred2.SAXDriver (non-validating) or gnu.xml.aelfred2.XmlReader (optionally validating). Otherwise the org.xml.sax.helpers.XMLReaderFactory may not return the parser you expect.

If using GNU JAXP as part of GNU Classpath, no configuration should be necessary.