When the javadoc is run as follows, the docmentation cannot be generated
and the following error messages are shown.
(/export/home/src/JDK1.1 is source tree of JDK1.1new)

javadoc -d /tmp/docs -sourcepath /export/home/src/JDK1.1/src/share/java java.lang

Loading source files for java.lang
java.lang.NullPointerException
        at sun.tools.javac.Main.getText(Main.java)
        at sun.tools.javac.BatchEnvironment.errorString(BatchEnvironment.java)
        at sun.tools.javac.BatchEnvironment.error(BatchEnvironment.java)
        at sun.tools.java.Environment.error(Environment.java)
        at sun.tools.java.Environment.error(Environment.java)
        at sun.tools.javac.BatchParser.importClass(BatchParser.java)
        at sun.tools.java.Parser.parseFile(Parser.java)
        at sun.tools.javac.BatchEnvironment.parseFile(BatchEnvironment.java)
        at sun.tools.javadoc.Main.main(Main.java:323)
java.lang.NullPointerException
        at sun.tools.javac.Main.getText(Main.java)
        at sun.tools.javac.BatchEnvironment.errorString(BatchEnvironment.java)
        at sun.tools.javac.BatchEnvironment.error(BatchEnvironment.java)
        at sun.tools.java.Environment.error(Environment.java)
        at sun.tools.javadoc.Main.main(Main.java:385)