FULL PRODUCT VERSION :
java version "1.9.0-ea"
Java(TM) SE Runtime Environment (build 1.9.0-ea-b66)
Java HotSpot(TM) 64-Bit Server VM (build 1.9.0-ea-b66, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Mac OS X 10.9.5

A DESCRIPTION OF THE PROBLEM :
The following code tries to convert a xml-string to a pretty-print-xml-string which works with jdk7 and jdk8 but not with jdk9 anymore.

REGRESSION.  Last worked in version 8u45

ADDITIONAL REGRESSION INFORMATION: 
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

java version "1.7.0_67"
Java(TM) SE Runtime Environment (build 1.7.0_67-b01)
Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
just javac and java. test fails if runtimeexception is thrown

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
<rss version="2.0">
    <channel>
        <title>Java Tutorials and Examples 1</title>
        <language>en-us</language>
    </channel>
</rss>
ACTUAL -
<rss version="2.0">
    <channel>  <title>Java Tutorials and Examples 1</title>  <language>en-us</language>
    </channel>
</rss>

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import org.w3c.dom.Document;
import org.w3c.dom.bootstrap.DOMImplementationRegistry;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSOutput;
import org.w3c.dom.ls.LSSerializer;
import org.xml.sax.InputSource;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;

public class PrettyPrint {
    public static void main(String[] args) throws Exception {
        String xml = "<rss version=\"2.0\"><channel>  <title>Java Tutorials and Examples 1</title>  <language>en-us</language></channel></rss>";
        Writer stringWriter = createPrettyPrint(xml);
        String actual = stringWriter.toString();
        String expected = "<rss version=\"2.0\">\n"
                          + "    <channel>\n"
                          + "        <title>Java Tutorials and Examples 1</title>\n"
                          + "        <language>en-us</language>\n"
                          + "    </channel>\n"
                          + "</rss>\n";

        if (!actual.equals(expected)) throw new RuntimeException("not equal");
    }

    private static Writer createPrettyPrint(String xml) throws Exception {
        DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
        DOMImplementationLS domImplementation = (DOMImplementationLS) registry.getDOMImplementation("LS");
        Writer stringWriter = new StringWriter();
        LSOutput formattedOutput = domImplementation.createLSOutput();
        formattedOutput.setCharacterStream(stringWriter);
        LSSerializer domSerializer = domImplementation.createLSSerializer();
        domSerializer.getDomConfig().setParameter("format-pretty-print", true);
        // Set this to true if the declaration is needed to be in the output.
        domSerializer.getDomConfig().setParameter("xml-declaration", false);
        domSerializer.write(toXmlDocument(xml), formattedOutput);
        return stringWriter;
    }

    private static Document toXmlDocument(String xmlString) throws Exception {
        InputSource xmlInputSource = new InputSource(new StringReader(xmlString));
        DocumentBuilder xmlDocumentBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        return xmlDocumentBuilder.parse(xmlInputSource);
    }
}
---------- END SOURCE ----------