如何使用Apache Camel XmlJsonDataFormat编组将XML字符串转换为JSON字符串

Question

I am trying to convert XML String in the below program to JSON String.

I am able to convert it from file but not from the string.

Any idea about this?

package com.tda.topology;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

import org.apache.camel.Exchange;   
import org.apache.camel.dataformat.xmljson.XmlJsonDataFormat;

public class Demo2 {

public static void main(String[] args) throws Exception {
    String xmlstring = "<soapenv:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:ser=\"http://services.web.post.list.com\"><soapenv:Header><authInfo xsi:type=\"soap:authentication\" xmlns:soap=\"http://list.com/services/SoapRequestProcessor\"><!--You may enter the following 2 items in any order--><username xsi:type=\"xsd:string\">user@email.com</username><password xsi:type=\"xsd:string\">password</password></authInfo></soapenv:Header></soapenv:Envelope>";
    XmlJsonDataFormat xmlJsonDataFormat = new XmlJsonDataFormat();
    xmlJsonDataFormat.setEncoding("UTF-8");
    xmlJsonDataFormat.setForceTopLevelObject(true);
    xmlJsonDataFormat.setTrimSpaces(true);
    xmlJsonDataFormat.setRootName("newRoot");
    xmlJsonDataFormat.setSkipNamespaces(true);
    xmlJsonDataFormat.setRemoveNamespacePrefixes(true);

    Exchange exchange;
    //exchange.setIn(in);

    InputStream stream = new ByteArrayInputStream(xmlstring.getBytes(StandardCharsets.UTF_8));
    //xmlJsonDataFormat.getSerializer().readFromStream(stream).toString();
    //xmlJsonDataFormat.marshal(exchange, graph, stream);

}
} 

Answer 1

You need to call start on your xmlJsonDataFormat object and add xom jar to your class path (if it's not already there). This is what worked for me:

xmlJsonDataFormat.start();
String json = xmlJsonDataFormat.getSerializer().readFromStream(stream).toString();

I was able to work this out through looking in the source. getSerialiser was returning null and so I searched in xmlJsonDataFormat for where the serializer was initialised and it's done so by the doStart method which is called in the super class's start method.

Disclaimer: not sure you're supposed to use XmlJsonDataFormat like this, it's usually meant for use in a camel route: from("direct:marshal").marshal(xmlJsonFormat).to("mock:json"); but I don't know your specific use case.