Web Application Description Language

The service is described using a set of resource elements. Each resource contains param elements to describe the inputs, and method elements which describe the request and response of a resource. The request element specifies how to represent the input, what types are required and any specific HTTP headers that are required. The response describes the representation of the service's response, as well as any fault information, to deal with errors.

The following listing shows an example of a WADL description for the Yahoo News Search application.

<application xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://wadl.dev.java.net/2009/02 wadl.xsd" xmlns:tns="urn:yahoo:yn" xmlns:yn="urn:yahoo:yn" xmlns:ya="urn:yahoo:api" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://wadl.dev.java.net/2009/02"> <grammars> <include href="NewsSearchResponse.xsd"/> <include href="Error.xsd"/> </grammars> <resources base="http://api.search.yahoo.com/NewsSearchService/V1/"> <resource path="newsSearch"> <method name="GET" id="search"> <request> <param name="appid" type="xsd:string" style="query" required="true"/> <param name="query" type="xsd:string" style="query" required="true"/> <param name="type" style="query" default="all"> <option value="all"/> <option value="any"/> <option value="phrase"/> </param> <param name="results" style="query" type="xsd:int" default="10"/> <param name="start" style="query" type="xsd:int" default="1"/> <param name="sort" style="query" default="rank"> <option value="rank"/> <option value="date"/> </param> <param name="language" style="query" type="xsd:string"/> </request> <response status="200"> <representation mediaType="application/xml" element="yn:ResultSet"/> </response> <response status="400"> <representation mediaType="application/xml" element="ya:Error"/> </response> </method> </resource> </resources> </application>

Java

There are multiple tools to generate java code from an existing WADL:

• Apache CXF
• Java API for RESTful Web Services, and its reference implementation, Jersey

Example WADL Generated by CXF

<app xmlns="http://research.sun.com/wadl/2006/10" xmlns:xs="http://www.w3.org/2001/XMLSchema"> <grammars> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" attributeFormDefault="unqualified" elementFormDefault="unqualified"> <xs:element name="appProfile" type="appProfile"/> <xs:element name="customerProfile" type="customerProfile"/> <xs:complexType name="customerProfile"> <xs:sequence> <xs:element minOccurs="0" name="accessPaymentServicesEnabled" type="xs:boolean"/> <xs:element maxOccurs="unbounded" minOccurs="0" name="attributes" nillable="true" type="attribute"/> <xs:element minOccurs="0" name="billingType" type="xs:string"/> <xs:element minOccurs="0" name="defaultCurrency" type="xs:string"/> <xs:element minOccurs="0" name="defaultSpendingLimitCurrency" type="xs:string"/> <xs:element minOccurs="0" name="maximumSpendingLimit" type="xs:double"/> <xs:element minOccurs="0" name="minimumSpendingLimit" type="xs:double"/> <xs:element minOccurs="0" name="customerCategory" type="xs:string"/> <xs:element minOccurs="0" name="customerEnabled" type="xs:boolean"/> <xs:element minOccurs="0" name="customerName" type="xs:string"/> <xs:element minOccurs="0" name="paymentNotificationEndpointAddress" type="xs:string"/> <xs:element minOccurs="0" name="pseCustomerId" type="xs:string"/> <xs:element minOccurs="0" name="resourceURL" type="xs:string"/> <xs:element minOccurs="0" name="settlementContractUuid" type="xs:string"/> <xs:element minOccurs="0" name="isSpendingLimitEnabled" type="xs:boolean"/> <xs:element minOccurs="0" name="abcCustomerId" type="xs:string"/> </xs:sequence> </xs:complexType> <xs:complexType name="attribute"> <xs:sequence> <xs:element minOccurs="0" name="key" type="xs:string"/> <xs:element minOccurs="0" name="value" type="xs:string"/> </xs:sequence> </xs:complexType> <xs:complexType name="appProfile"> <xs:sequence> <xs:element minOccurs="0" name="appEnabled" type="xs:boolean"/> <xs:element minOccurs="0" name="appName" type="xs:string"/> <xs:element minOccurs="0" name="appPassword" type="xs:string"/> <xs:element minOccurs="0" name="appUserName" type="xs:string"/> <xs:element minOccurs="0" name="appUuid" type="xs:string"/> <xs:element maxOccurs="unbounded" minOccurs="0" name="attributes" nillable="true" type="attribute"/> <xs:element minOccurs="0" name="description" type="xs:string"/> <xs:element minOccurs="0" name="customerName" type="xs:string"/> <xs:element minOccurs="0" name="resourceURL" type="xs:string"/> <xs:element minOccurs="0" name="serviceContractName" type="xs:string"/> <xs:element minOccurs="0" name="abcAppId" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:schema> </grammars> <resources base="http://mpsamara-mobl-vm1:9078/customermanagement/v1"> <resource path="/customers"> <resource path="/"> <method name="DELETE"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> <method name="GET"> <request> <param name="page" style="query" type="xs:int"/> <param name="partialCustomerName" style="query" type="xs:string"/> </request> <response> <representation mediaType="app/json"/> </response> </method> <method name="POST"> <request> <representation mediaType="app/json"/> </request> <response> <representation mediaType="app/json"/> </response> </method> <method name="PUT"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}"> <method name="DELETE"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}"> <param name="customerUserName" style="template" type="xs:string"/> <method name="GET"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> <method name="POST"> <request> <representation mediaType="app/json"/> </request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}"> <method name="PUT"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps"> <method name="DELETE"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps"> <param name="customerUserName" style="template" type="xs:string"/> <method name="GET"> <request> <param name="page" style="query" type="xs:int"/> </request> <response> <representation mediaType="app/json"/> </response> </method> <method name="POST"> <request> <representation mediaType="app/json"/> </request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps"> <method name="PUT"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps/{appName}"> <method name="DELETE"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps/{appName}"> <param name="customerUserName" style="template" type="xs:string"/> <param name="appName" style="template" type="xs:string"/> <method name="GET"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> <method name="POST"> <request> <representation mediaType="app/json"/> </request> <response> <representation mediaType="app/json"/> </response> </method> </resource> <resource path="/{customerUserName}/apps/{appName}"> <method name="PUT"> <request></request> <response> <representation mediaType="app/json"/> </response> </method> </resource> </resource> </resources> </app>