How can I this xml document transform in java?

I need to convert this file to java. I'm taking the file as a document and need to edit it by making a change to the namespace.

  <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="http://www.oorsprong.org/websamples.countryinfo">
   <soapenv:Header/>
   <soapenv:Body>
    <web:CapitalCity>
     <web:sCountryISOCode>...</web:sCountryISOCode>
    </web:CapitalCity>
   </soapenv:Body>
  </soapenv:Envelope>`

to:

 <Envelope>
   <Header/>
   <Body>
    <CapitalCity>
     <sCountryISOCode>...</sCountryISOCode>
    </CapitalCity>
   </Body>
 </Envelope>

How can I do?

my code:

String xml="<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:web=\"http://www.oorsprong.org/websamples.countryinfo\">\r\n" + 
                    "   <soapenv:Header/>\r\n" + 
                    "   <soapenv:Body>\r\n" + 
                    "    <web:CapitalCity>\r\n" + 
                    "     <web:sCountryISOCode>...</web:sCountryISOCode>\r\n" + 
                    "    </web:CapitalCity>\r\n" + 
                    "   </soapenv:Body>\r\n" + 
                    "  </soapenv:Envelope>";
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
Document doc = dbf.newDocumentBuilder().parse(new InputSource(new StringReader(xml)));
StringWriter buf = new StringWriter();
Transformer xform = TransformerFactory.newInstance().newTransformer();
xform.transform(new DOMSource(doc), new StreamResult(buf));
String output = buf.getBuffer().toString().replaceAll("<[^/](.+?):", "<");
String output2=output.replaceAll("</(.+?):", "</");
System.out.println(output2);

I want to do this without using regex, is this possible?

Solution

I made using xslt:

public String envelopeDocument_2_XSL(Document data) throws IOException, TransformerFactoryConfigurationError, TransformerException {
    URL xsltURL = getClass().getClassLoader().getResource("XSLT.xsl");
    Source stylesource = new StreamSource(xsltURL.openStream(), xsltURL.toExternalForm());

    Transformer transformer = TransformerFactory.newInstance().newTransformer(stylesource);

    StringWriter stringWriter = new StringWriter();
    transformer.transform(new DOMSource(data), new StreamResult(stringWriter));

    return stringWriter.toString();
}

When the xml document above is given to this function, it removes the namespaces.

XSLT code that removes namespaces:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:template match="node()">
        <xsl:copy>
            <xsl:apply-templates select="node() | @*" />
        </xsl:copy>
    </xsl:template>
    <xsl:template match="*">
        <xsl:element name="{local-name()}">
            <xsl:apply-templates select="node() | @*" />
        </xsl:element>
    </xsl:template>
    <xsl:template match="@*">
        <xsl:copy>
            <xsl:apply-templates select="node() | @*" />
        </xsl:copy>
    </xsl:template>
      <xsl:template match="comment()[contains(., '')]" />
</xsl:stylesheet>