javax/xml/parsers/DocumentBuilder.class error on Windows

[dwlee]

I made ros android app on windows with build.gradle script used in rosjava. It is working well when building gradle but the Run app is failed with following error.

trouble processing "javax/xml/parsers/DocumentBuilder.class":

    Ill-advised or mistaken usage of a core class (java.* or javax.*)
    when not building a core library.

    This is often due to inadvertently including a core library file
    in your application's project, when using an IDE (such as
    Eclipse). If you are sure you're not intentionally defining a
    core class, then this is the most likely explanation of what's
    going on.

    However, you might actually be trying to define a class in a core
    namespace, the source of which you may have taken, for example,
    from a non-Android virtual machine project. This will most
    assuredly not work. At a minimum, it jeopardizes the
    compatibility of your app with future versions of the platform.
    It is also often of questionable legality.

    If you really intend to build a core library -- which is only
    appropriate as part of creating a full virtual machine
    distribution, as opposed to compiling an application -- then use
    the "--core-library" option to suppress this error message.

    If you go ahead and use "--core-library" but are in fact
    building an application, then be forewarned that your application
    will still fail to build or run, at some point. Please be
    prepared for angry customers who find, for example, that your
    application ceases to function once they upgrade their operating
    system. You will be to blame for this problem.

    If you are legitimately using some code that happens to be in a
    core package, then the easiest safe alternative you have is to
    repackage that code. That is, move the classes in question into
    your own package namespace. This means that they will never be in
    conflict with core system classes. JarJar is a tool that may help
    you in this endeavor. If you find that you cannot do this, then
    that is an indication that the path you are on will ultimately
    lead to pain, suffering, grief, and lamentation.

For not using gradle, I made libs directory in android project and copied all jar files in it.
So, I tried to run app, same error was occurred. For finding reason of error, I delete jar file one by one from android project, and I realized the reason of problem that xml-apis.jar is led to above error.
Do you know why does it occur error?