Overview of the ServiceMix 2.x HTTP Binding Example
The following procedure describes how to run the HTTP Binding example and provides details regarding what it does. For information on the business use case, please refer to: Use Case for HTTP Binding.
The HTTP Binding example illustrates:
- use of declarative programming
- how to perform HTTP binding in ServiceMix
The source code for the HTTP Binding example is located in the ServiceMix installation directory under the examples\http-binding
directory in the servicemix.xml
file. It is recommended that you refer to the source code while reading this document.
This example shows how to use the HTTP bindings to handle a simple HTTP post. One component acts as the HTTP server thahttp://docs.codehaus.org/display/SM/Http+Binding+Ja
Viewt listens on http://localhost:8912 while another invokes a remote service implemented as a URLEndpoint. A simple HTTP client is provided so that a simple post can be sent to the server.
Running the HTTP Binding Example
- From a command shell, go to the HTTP Binding example directory:
where
cd [servicemix_install_dir]\examples\http-binding
servicemix_install_dir
is the directory in which ServiceMix was installed. - Then type:
[servicemix_install_dir]\bin\servicemix servicemix.xml
- To start sending and receiving messages from the HTTP server, send an initial message. To do this, compile and run a simple HTTP client. The client is built and run from source code using Ant. Execute Ant from the HTTP Binding directory:
servicemix_install_dir\examples\http-binding
. To run the HTTP client type:
ant
Ant will compile and run the simple HTTP client, HttpClient, which performs a simple post on the HTTP Server into the ServiceMix container before returning the results to the console.
Stopping the HTTP Binding Example
To terminate the HTTP Binding example, type "CTRL-C" in the command shell in which it is running and answer "y" to the "Terminate batch job (y/n)?" question.
How it Works
The diagram below illustrates the flow of messages through the HTTP Binding components:
Messages flow through the components as follows:
- HttpClient, a java stand-alone program connects to http://localhost:8912
through the URLConnection class. HttpClient sends the file "request.xml" to this port.
- httpReceiver, an HTTP server, being a listener on http://localhost:8912
receives the message.
- httpReceiver sends the message to stockQuote as specified in its destinationService property, via NMR.
- stockQuote sends the message into another service, soapEndpoint for processing.
- soapEndpoint sends the response to stockQuote.
- stockQuote sends the response to httpReceiver via NMR.
- httpReceiver sends the response to http://localhost:8912
.
- HttpClient reads the response.
- The response is printed on the console.
Typical output looks like the following:
Output from running [servicemix_install_dir]\bin\servicemix servicemix.xml
:
Loading ServiceMix from file: C:\exist\servicemix\servicemix-2.0.2\examples\http -binding\servicemix.xml 17:34:34.768 EVENT Starting Jetty/4.2.20RC0 17:34:34.848 EVENT Started ServletHttpContext[/] 17:34:34.858 EVENT Started SocketListener on 127.0.0.1:8912 17:34:34.858 EVENT Started org.mortbay.jetty.Server@1f06dc3
Output from running Ant:
Buildfile: build.xml init: compile: run: [echo] Running example client [java] <?xml version="1.0" encoding="UTF-8"?><soap:Envelope xmlns:soap="htt p://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSch ema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenc="http:/ /schemas.xmlsoap.org/soap/encoding/" soap:encodingStyle="http://schemas.xmlsoap. org/soap/encoding/"><soap:Body><n:getQuoteResponse xmlns:n="urn:xmethods-delayed -quotes"><Result xsi:type="xsd:float">88.8</Result></n:getQuoteResponse></soap:B ody></soap:Envelope>asdf BUILD SUCCESSFUL Total time: 6 seconds
Details
The following table provides more details about the function of each component and bean in the servicemix.xml file.
Component or Bean ID |
Description |
---|---|
jbi |
jbi is the "id" of the JBI container and provides the basic infrastructure services for the following components: |
httpReceiver |
This component is an HTTP server that listens at http://localhost/8912![]() . It forwards the message it receives from this URL to stockQuote as specified in its destinationService property in the |
stockQuote |
This is a SaajBinding component that invokes an endpoint service called soapEndpoint. It is implemented by the SaajBinding class which converts an inbound JBI message into a SAAJ (Soap With Attachments for Java) request-response and sends the response back to httpReceiver. This provides a message centric way of invoking SOAP services inside providers such as Apache Axis |
soapEndpoint |
A URLEndpoint object contains a URL, which is used to make connections to the remote party. A stand-alone client can pass a URLEndpoint object to the SOAPConnection method call to send a message. |
Useful Code Hints
This section describes the start-up sequence and how the ServiceMix container interacts with the HTTP Binding application. The Java class files are located in the servicemix-2.0.2.jar file in the ServiceMix installation directory. To look at the Java source code, unjar and decompile the .class files or download the source code.
Viewing the Java source code is recommended for understanding the information in this section.
- The ServiceMix container reads the
servicemix.xml
file and instantiates the components specified through SpringJBIContainer class. - The container calls the afterPropertiesSet() method of SpringJBIContainer to register the components and the activationSpecs. In this case, httpReceiver and stockQuote are registered as activationSpecs.
- SpringJBIContainer uses ActivationSpec class as the container for component specific properties such as routing information.
Some of its ActivationSpec's methods are:
- setId - takes the spring:id=jbi and sets the id of the container to "jbi"
- setcomponentName - sets componentName to httpReceiver on first invocation and "stockQuote" in the next
- setEndpoint - sets the endpoint properties from the servicemix.xml file
- setService - sets the service properties from xml file
- setDestinationService = sets the destinationService for each component
HttpConnector Details
- The ServiceMix container reads the
servicemix.xml
file and sees it needs to instantiate a HttpConnector. - The container calls the init() method of HttpConnector. The init() method sets the host and port property of the SocketListener in which the HttpConnector will listen message to.
- The container calls the start() method of HttpConnector. The start() method will:
A. Sets the listener property of the server.
B. Creates a new HttpContext that contains a ServletHandler class. ServletHandler maps requests to servlets that implement the javax.servlet.http.HttpServlet API. In this case it sends request to BindingServlet.
C. Server is started.
stockQuote Details
Related Documentation
For more information on the following topics please see: