How to create a client app for a RESTful service from wadl?

问题

Given an application.wadl file, how do I generate Client app (Spring or any) and domain objects from a wadl file?

I tried :

wadl2java https://genologics.com/files/permanent/API/2.5/application.wadl

WADLToJava Error: java.lang.IllegalStateException: Single WADL resources element is expected

回答1:

This is my findings by reviewing the source-code:

As SourceGenerator.java, wadltojava is trying to get the "resources" element from the "application" element and expects it to be one only.

private void generateResourceClasses(Application app, GrammarInfo gInfo, 
                                         Set<String> typeClassNames, File src) {
        Element appElement = app.getAppElement();
        List<Element> resourcesEls = getWadlElements(appElement, "resources");
        if (resourcesEls.size() != 1) {
            throw new IllegalStateException("Single WADL resources element is expected");
        }

        List<Element> resourceEls = getWadlElements(resourcesEls.get(0), "resource");
        if (resourceEls.size() == 0) {
            throw new IllegalStateException("WADL has no resource elements");
        }
        ........
   }

I checked the WADL you provided and seems like there is only one "resources" element.

On checking further in getWadlElements() method is using getWadlNamespace():

private List<Element> getWadlElements(Element parent, String name) {
        List<Element> elements = parent != null 
            ? DOMUtils.getChildrenWithName(parent, getWadlNamespace(), name)
            : CastUtils.cast(Collections.emptyList(), Element.class);
        if (!"resource".equals(name)) {    
            for (int i = 0; i < elements.size(); i++) {
                Element el = elements.get(i);
                Element realEl = getWadlElement(el);
                if (el != realEl) {
                    elements.set(i, realEl);
                }
            }
        }
        return elements;
    }

The namespace used here in WadlGenerator.java is

public static final String WADL_NS = "http://wadl.dev.java.net/2009/02";

But in your WADL the namespace seems to be different as below, and may be causing issue.

<wadl:application xmlns:wadl="http://research.sun.com/wadl/2006/10" xmlns:xs="http://www.w3.org/2001/XMLSchema">

It seems that you are using CXF so as per my understanding, I would suggest you to use the same framework which is used to generate the WADL.

Update: Or, have the WADL and XSD's on your local and modify the namespace manually in WADL to the latest one and try again.

来源：https://stackoverflow.com/questions/31492866/how-to-create-a-client-app-for-a-restful-service-from-wadl

标签

rest

spring-mvc

cxf

wadl