Camel XSLT transformation - xslt

Question

I am trying to use the XSLT component to do dynamic transformation from XML. Is it possible to pass in a java variable in the URI as XSLT template?
For example:
from("direct:foo").
to("xslt:${fee}").
to("direct:output");
foo - is a XML payload,
fee - XSLT template stored as java.lang.String,
output - xml payload

Answer 1

You can assign your variable into message header by some conditions:
.setHeader("TemplateLocation").constant("OSGI-INF/xsl/pretty.xsl")
After, you can use Recipient List EIP:
.recipientList().simple("xslt:${header.TemplateLocation}")
or you can use toD:
.toD("xslt:${header.TemplateLocation}")
Working example:
#Override
protected RouteBuilder createRouteBuilder() {
return new RouteBuilder() {
#Override
public void configure() throws Exception {
from("direct:start")
.routeId("xsltTest")
.log(LoggingLevel.INFO, "XML input : \n${body}")
.setHeader("TemplateLocation").constant("OSGI-INF/xsl/pretty.xsl")
//.recipientList().simple("xslt:${header.TemplateLocation}")
.toD("xslt:${header.TemplateLocation}")
.to("log:end?level=INFO&showAll=true&multiline=true");
}
};
}
And there is no way to use a string variable as an xslt template, as far as I know.

Answer 2

Based on my knowledge
Your XSLT poller has a dynamic expression as subdirectory (${fee}).
As far as I know you cannot have a dynamic from address in a Camel
route. Because this would mean that you could consume from multiple
endpoints.
You can have it as separate file and call it like this
to("xslt:file:///foo/bar.xsl").
For more details XSLT

Answer 3

You cannot use a dynamic stylesheet (dynamic content) with the XSL component of Camel.
The most dynamic thing you can do is a dynamic reference to a static file like this:
.toD("xslt:${expressionWithFileReference}")
However, you can simply call a Java bean to do what you want and call it from the route:
.bean(javaBeanReference or new YourJavaBean())
In the Bean you can use Camel annotations to inject header(s), properties and the body into a method. Whatever you need from the current Camel Exchange.
public void yourMethod(
#Header(headername) String parameterName,
#Body Type parameterName) {
...
}

Answer 4

As Camel does not have support for dynamic XSLT input stream, I had to create my own Transformer. This might help someone
Here is my code snippet. I used camel processor as below
#Override
public void process(Exchange exchange) throws Exception {
XmlMapper xmlMapper = new XmlMapper();
Target target = xmlMapper.readValue(transform(getInputStreamFromDocument(xmlPayload), new ByteArrayInputStream(xsltTemplate.getBytes())), target.class);
}
public byte[] transform(InputStream dataXML, InputStream inputXSL)
throws TransformerException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(new StreamSource(inputXSL));
StreamSource in = new StreamSource(dataXML);
StreamResult out = new StreamResult(bos);
transformer.transform(in, out);
return bos.toByteArray();
}