Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!npeer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail
From: zyng <xsli2@yahoo.com>
Newsgroups: comp.lang.java.programmer
Subject: Re: the problem for accessing the classes in rt.jar
Date: Wed, 18 Apr 2012 08:35:05 -0700 (PDT)
Organization: http://groups.google.com
Lines: 24
Message-ID: <21528069.1815.1334763305959.JavaMail.geo-discussion-forums@yntt13>
References: <22583724.345.1334591253848.JavaMail.geo-discussion-forums@vbvf19> <4f8e0210$0$290$14726298@news.sunsite.dk> <14699406.1250.1334754816127.JavaMail.geo-discussion-forums@vbyj26> <slrnjothhs.kvi.avl@gamma.logic.tuwien.ac.at> <29910219.1583.1334761581496.JavaMail.geo-discussion-forums@ynjm4>
NNTP-Posting-Host: 205.156.36.56
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
X-Trace: posting.google.com 1334763306 1032 127.0.0.1 (18 Apr 2012 15:35:06 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Wed, 18 Apr 2012 15:35:06 +0000 (UTC)
Cc: avl@logic.at
In-Reply-To: <29910219.1583.1334761581496.JavaMail.geo-discussion-forums@ynjm4>
Complaints-To: groups-abuse@google.com
Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=205.156.36.56; posting-account=oo44OQoAAABMDvaRlaO3SeQ5MVbxqLdH
User-Agent: G2/1.0
X-Received-Bytes: 2462
Xref: csiph.com comp.lang.java.programmer:13638

My goodness. The problem is solved. By searching Google, I found this link which provides the explanation and the answer:

http://stackoverflow.com/questions/4065401/using-internal-sun-classes-with-javac

I copied his answer here:
"When javac is compiling code it doesn't link against rt.jar by default. Instead it uses special symbol file lib/ct.sym with class stubs.

Surprisingly this file contains many but not all of internal sun classes. In my case one of those more-internal-than-usual classes was sun.awt.event.IgnorePaintEvent.

And the answer to my question is: javac -XDignore.symbol.file

That's what javac uses for compiling rt.jar."

So, in my build.xml, the target "compile", I have:
	<target name="compile" depends="prepare">
		<javac srcdir="${src.dir}" destdir="${build.dir}" compiler="modern" fork="yes" debug="on">
			<classpath refid="project.classpath"/>
			<compilerarg value="-Xlint"/>
			<compilerarg value="-verbose"/>
			<compilerarg value="-XDignore.symbol.file"/>
		</javac>
	</target>

In project.classpath, I don't need to explicitly reference rt.jar at all! Now it compiles fine.