| Sample Number | 101 |
|---|
| Level | Introductory |
| Description | This sample demonstrates the usage of UltraESB to proxy Text messages/responses |
Use Case
| Excerpt |
|---|
I have a service that returns text format responses and I want to proxy this text service and mediate the text responses. The UltraESB can be used to proxy any type of payload, including SOAP 1.1/1.2, XML, Text, HTML, Hessian, EDI, CSV, binary etc.. this example shows how a plain text response of a Servlet could be proxied through the UltraESB. |
As shown in the above diagram, instead of directly talking to the text service, UltraESB acts as the proxy for all the requests going to the back-end server, making it possible to mediate text responses.
Sample Configuration
The configuration for a text proxy is trivial as it is just a proxy service to forward the messages into the text service back-end and return the response back to the caller.
| Code Block |
|---|
| title | Proxy service configuration to proxy text responses |
|---|
| theme | Eclipse |
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| linenumbers | true |
|---|
| language | html/xml |
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|
<u:proxy id="text-proxy">
<u:transport id="http-8280">
<u:property name="ultra.transport.url" value="text-proxy*"/>
</u:transport>
<u:target>
<u:inDestination>
<u:address>http://localhost:9000/service/TextServlet</u:address>
</u:inDestination>
<u:outDestination>
<u:address type="response"/>
</u:outDestination>
</u:target>
</u:proxy> |
The proxy service URL has been specified by the "ultra.transport.url" to be anything starts with the "text-proxy". The request message will be forwarded to the back-end text servlet and the response back to the caller, without any mediation in this case. Adding mediation for the response path is just a matter of adding a out sequence for the target.
| Info |
|---|
| title | Proxy service can handle any content type if not constrained |
|---|
|
Unless a content type constraint is forced, a proxy service can handle SOAP, REST, Hessian, JSON, Text or binary etc |
In Action
To try out this sample, start the ToolBox and the sample Jetty server within it. The sample server hosts a servlet that outputs plain text. Using the HTTP/S client of the ToolBox, one can issue a GET request to the URL http://localhost:9000/service/TextServlet to get this response directly from the servlet as shown below.
| Panel |
|---|
| bgColor | #EEEEFF |
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| titleBGColor | #E0E0D0 |
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| title | Response from the back-end text servlet |
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| borderColor | #BBBBBB |
|---|
|
HTTP/1.1 200 OK
Content-Type: text/plain; charset=iso-8859-1
Connection: close
Server: Jetty(6.1.21)
Plain text Hello World |
Now, start the sample configuration 101 of the UltraESB through the ToolBox, or the command line as follows.
| Code Block |
|---|
|
$ cd /opt/ultraesb-1.6.0/bin
$ ./ultraesb.sh -sample 101 |
Issuing a GET request to the text-proxy of the UltraESB at URL http://localhost:8280/service/text-proxy you will now get the same response through the UltraESB.
| Panel |
|---|
| bgColor | #EEEEFF |
|---|
| titleBGColor | #E0E0D0 |
|---|
| title | Response from the ESB |
|---|
| borderColor | #BBBBBB |
|---|
|
HTTP/1.0 200 OK
Content-Type: text/plain; charset=iso-8859-1
Date: Wed, 13 Jan 2010 05:51:10 GMT
Server: UltraESB/1.6.0
Content-Length: 23
Connection: close
Plain text Hello World |
Note that the advantage would be in mediating the request and response, performing transformations or other such actions via the UltraESB.
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