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.
附一些Log4j问题解决数参考的资料：
方案1：
你先將你程式內部的 log4j.properties or log4j.xml 全部拿掉，再 deploy
看看。如果没问题再逐一将 自己的 config 一项一项放进
\jboss\server\default\conf\log4j.xml 测试。
方案2：
application若有自己的log4j war及设定项，而导致JBoss启动时出现
"ERROR: invalid console appender config detected, console stream is
looping." 错误信息时，只要去JBoss
server里的conf资料夹中的jboss-service.xml中的org.jboss.logging.Log4jService的设定区段中
加个参数：<attribute
name="CatchSystemOut">false</attribute>即可，如：
<mbean code="org.jboss.logging.Log4jService"
name="jboss.system:type=Log4jService,service=Logging"><attribute
name="ConfigurationURL">resource:log4j.xml</attribute><attribute
name="CatchSystemOut">false</attribute><attribute
name="Log4jQuietMode">true</attribute></mbean>
