xdocs/0_94/rest-ws.html - axis-axis2-java-core - Git at Google

 <html>
 <head>
   <meta http-equiv="content-type" content="">
   <title>RESTful Web Services Support</title>
 </head>

 <body lang="en">
 <h1>RESTful Web services Support</h1>

 <p>REST provides access to resources through the two methods GET and POST.
 REST Web services are a reduced subset of the usual Web service stack.</p>

 <p>The Axis2 REST implementation assumes the following properties:</p>
 <ol>
   <li>REST Web services are Synchronous and Request Response in nature.</li>
   <li>When REST Web services are accessed via GET, the service and the
     operations are identified based on the URL. The parameters are assumed as
     parameters of the Web service. In this case the GET based REST Web
     services supports only simple types as arguments.</li>
   <li>POST based web services do not need a SOAP Envelope or a SOAP Body.
     REST Web Services do not have Headers and the payload is sent
   directly.</li>
 </ol>

 <p>Axis2 can be configured as a REST Container and can be used to send and
 receive RESTful Web services requests and responses. REST Web services can be
 accessed in two ways, i.e. using HTTP GET and POST.</p>

 <h2>Doing REST web services with HTTP POST</h2>

 <p>The REST default HTTP interface is POST. It can be enabled in the
 Server/Client side by adding the following line to the axis2.xml file.</p>
 <font color="blue">&lt; parameter name="enableREST" locked="false" &gt; true
 &lt;/parameter&gt; </font>

 <p>It however acts as both a REST endpoint and SOAP endpoint. When a Message
 is received, if the content type is text/xml and if the SOAP Action Headers
 are missing, then the Message is treated as a RESTful Message. Else it is
 treated as a usual SOAP Message.</p>

 <p>On sending a message out, the fact that the message is RESTful or not, can
 be decided from the client API or by deployment descriptor of the client.</p>
 <ol>
   <li>By adding an entry in the client repositories axis2.xml file.</li>
   <li>Setting as a property in client API e.g. <source>
     <pre>...
 Options options = new Options();
 options.setProperty(Constants.Configuration.ENABLE_REST, Constants.VALUE_TRUE);
 ...</pre>
     </source></li>
 </ol>

 <h3>Sample REST - HTTP POST Client</h3>

 <p>There is an example named, userguide.clients.RESTClient.java which
 demonstrates the usage of the above, using the "echo"operation of the
 <source></p>
 <pre>userguide.example1.MyService </pre>

 <p>of the samples.The class source will be as follows:</p>

 <p><source></p>
 <pre>public class RESTClient {

     private static String toEpr = "http://localhost:8080/axis2/services/MyService";

     public static void main(String[] args) throws AxisFault {

         Options options = new Options();
         options.setTo(new EndpointReference(toEpr));
         options.setListenerTransportProtocol(Constants.TRANSPORT_HTTP);
         options.setUseSeparateListener(false);
         options.setProperty(Constants.Configuration.ENABLE_REST, Constants.VALUE_TRUE);

         Call call = new Call();
         call.setClientOptions(options);

         OMElement result = call.invokeBlocking("echo", getPayload());

         try {
             XMLStreamWriter writer = XMLOutputFactory.newInstance()
                    .createXMLStreamWriter(System.out);
             result.serialize(writer);
             writer.flush();
         } catch (XMLStreamException e) {
             e.printStackTrace();
         } catch (FactoryConfigurationError e) {
             e.printStackTrace();
         }
     }

     private static OMElement getPayload() {
         OMFactory fac = OMAbstractFactory.getOMFactory();
         OMNamespace omNs = fac.createOMNamespace(
                 "http://example1.org/example1", "example1");
         OMElement method = fac.createOMElement("echo", omNs);
         OMElement value = fac.createOMElement("Text", omNs);
         value.addChild(fac.createText(value, "Axis2 Echo String "));
         method.addChild(value);

         return method;
     }
 }</pre>
 </source>
 <h2>Access a REST Web Service Via HTTP GET</h2>

 <p>Axis2 allow users to access Web services that have simple type parameters
 via HTTP GET. For example the following URL requests the Version Service via
 HTTP GET. But the Web service arriving via GET assumes REST. Other parameters
 are converted in to XML and put in to the SOAP Body.</p>
 <source><pre>http://127.0.0.1:8080/axis2/services/version/getVersion</pre>
 </source>
 <p>Result can be shown in the browser as follows:</p>
 <img src="images/userguide/http-get-ws.png">

 <p>For example, the following request, <source></p>
 <pre>http://127.0.0.1:8080/axis2/services/version/getVersion</pre>
 </source>will be converted to the following SOAP Message for processing by
 Axis2.<source>
 <pre>
    &lt;soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"&gt;
       &lt;soapenv:Body&gt;
           &lt;axis2:getVersion xmlns:axis2="http://ws.apache.org/goGetWithREST" /&gt;
       &lt;/soapenv:Body&gt;
    &lt;/soapenv:Envelope&gt;
     </pre>
 </source></body>
 </html>
	<html>
	<head>
	<meta http-equiv="content-type" content="">
	<title>RESTful Web Services Support</title>
	</head>

	<body lang="en">
	<h1>RESTful Web services Support</h1>

	<p>REST provides access to resources through the two methods GET and POST.
	REST Web services are a reduced subset of the usual Web service stack.</p>

	<p>The Axis2 REST implementation assumes the following properties:</p>
	<ol>
	<li>REST Web services are Synchronous and Request Response in nature.</li>
	<li>When REST Web services are accessed via GET, the service and the
	operations are identified based on the URL. The parameters are assumed as
	parameters of the Web service. In this case the GET based REST Web
	services supports only simple types as arguments.</li>
	<li>POST based web services do not need a SOAP Envelope or a SOAP Body.
	REST Web Services do not have Headers and the payload is sent
	directly.</li>
	</ol>

	<p>Axis2 can be configured as a REST Container and can be used to send and
	receive RESTful Web services requests and responses. REST Web services can be
	accessed in two ways, i.e. using HTTP GET and POST.</p>

	<h2>Doing REST web services with HTTP POST</h2>

	<p>The REST default HTTP interface is POST. It can be enabled in the
	Server/Client side by adding the following line to the axis2.xml file.</p>
	<font color="blue">< parameter name="enableREST" locked="false" > true
	</parameter> </font>

	<p>It however acts as both a REST endpoint and SOAP endpoint. When a Message
	is received, if the content type is text/xml and if the SOAP Action Headers
	are missing, then the Message is treated as a RESTful Message. Else it is
	treated as a usual SOAP Message.</p>

	<p>On sending a message out, the fact that the message is RESTful or not, can
	be decided from the client API or by deployment descriptor of the client.</p>
	<ol>
	<li>By adding an entry in the client repositories axis2.xml file.</li>
	<li>Setting as a property in client API e.g. <source>
	<pre>...
	Options options = new Options();
	options.setProperty(Constants.Configuration.ENABLE_REST, Constants.VALUE_TRUE);
	...</pre>
	</source></li>
	</ol>

	<h3>Sample REST - HTTP POST Client</h3>

	<p>There is an example named, userguide.clients.RESTClient.java which
	demonstrates the usage of the above, using the "echo"operation of the
	<source></p>
	<pre>userguide.example1.MyService </pre>

	<p>of the samples.The class source will be as follows:</p>

	<p><source></p>
	<pre>public class RESTClient {

	private static String toEpr = "http://localhost:8080/axis2/services/MyService";

	public static void main(String[] args) throws AxisFault {

	Options options = new Options();
	options.setTo(new EndpointReference(toEpr));
	options.setListenerTransportProtocol(Constants.TRANSPORT_HTTP);
	options.setUseSeparateListener(false);
	options.setProperty(Constants.Configuration.ENABLE_REST, Constants.VALUE_TRUE);

	Call call = new Call();
	call.setClientOptions(options);

	OMElement result = call.invokeBlocking("echo", getPayload());

	try {
	XMLStreamWriter writer = XMLOutputFactory.newInstance()
	.createXMLStreamWriter(System.out);
	result.serialize(writer);
	writer.flush();
	} catch (XMLStreamException e) {
	e.printStackTrace();
	} catch (FactoryConfigurationError e) {
	e.printStackTrace();
	}
	}

	private static OMElement getPayload() {
	OMFactory fac = OMAbstractFactory.getOMFactory();
	OMNamespace omNs = fac.createOMNamespace(
	"http://example1.org/example1", "example1");
	OMElement method = fac.createOMElement("echo", omNs);
	OMElement value = fac.createOMElement("Text", omNs);
	value.addChild(fac.createText(value, "Axis2 Echo String "));
	method.addChild(value);

	return method;
	}
	}</pre>
	</source>
	<h2>Access a REST Web Service Via HTTP GET</h2>

	<p>Axis2 allow users to access Web services that have simple type parameters
	via HTTP GET. For example the following URL requests the Version Service via
	HTTP GET. But the Web service arriving via GET assumes REST. Other parameters
	are converted in to XML and put in to the SOAP Body.</p>
	<source><pre>http://127.0.0.1:8080/axis2/services/version/getVersion</pre>
	</source>
	<p>Result can be shown in the browser as follows:</p>
	<img src="images/userguide/http-get-ws.png">

	<p>For example, the following request, <source></p>
	<pre>http://127.0.0.1:8080/axis2/services/version/getVersion</pre>
	</source>will be converted to the following SOAP Message for processing by
	Axis2.<source>
	<pre>
	<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
	<soapenv:Body>
	<axis2:getVersion xmlns:axis2="http://ws.apache.org/goGetWithREST" />
	</soapenv:Body>
	</soapenv:Envelope>
	</pre>
	</source></body>
	</html>