Convert java attributes to start with upperCase when being written to xml file using XStream

    if (xstream == null) {
                xstream = new XStream(){
                  
                    @Override
                    protected MapperWrapper wrapMapper(MapperWrapper next) {
                            return new UpperCaseMapper(next);
                    }
                };
            }
           
    private static class UpperCaseMapper extends MapperWrapper {
        public UpperCaseMapper(Mapper wrapped) {
                super(wrapped);
        }

        @Override
        public String serializedMember(Class type, String memberName) {
            String camelCase = memberName.substring(0, 1).toUpperCase() + memberName.substring(1);
            return super.serializedMember(type, camelCase);
        }
       
        @Override
        public String realMember(Class type, String serialized) {
                String camelCase = serialized.substring(0, 1).toLowerCase()
                                + serialized.substring(1);
                return super.realMember(type, camelCase);
        }
    }

Using XStream to set xmlns attribute (xml namespace)

Thoughtworks xstream does not have an API to add xmlns attribute to xml root element. There is a work around to do the same using their useAttributeFor() API. Its a bit of hack but serves the purpose.

java pojo
public class TestXmlns {
    private String name;
    private String address;
    private String xmlns;
   
    ...get/set for above attributes.
   
}

create an instance of xstream and add below configuration
xstream.useAttributeFor(TestXmlns.class, "xmlns");

Example:
TestXmlns x1 = new TestXmlns();
x1.setName("abc");
x1.setAddress("zyx");
z1.setXmlns("http://com.company.mytest");

XStream xstream = new XStream();
xstream.useAttributeFor(TestXmlns.class, "xmlns");

String xmlString = xstream.toXML(x1);

output
<TestXmlns xmlns="http://com.company.mytest">
    <name>abc</name>
    <address>xyz</address>
</TestXmlns>