there is a error report for ws topdown that is not required

when use ws module to generate web service from a wsdl, if you use jre, not jdk, there is a error report:
[ERROR] com.sun.tools.javac.Main is not available in the classpath, requires Suns JDK version 5.0 or latter.
unknown location

compilation failed, errors should have been reported
Failed to invoke WsImport
java.lang.IllegalStateException: WsImport invocation failed. Try the verbose switch for more information
at org.jboss.ws.tools.jaxws.impl.SunRIConsumerImpl.consume(SunRIConsumerImpl.java:220)
at org.jboss.wsf.spi.tools.cmd.WSConsume.importServices(WSConsume.java:223)
at org.jboss.wsf.spi.tools.cmd.WSConsume.main(WSConsume.java:81)

This is caused by ws runtime, which need jdk to complie these codes, but in jboss tools, we don't need ws runtime to compile.