Tuesday, November 27, 2012

XML validation against schema

We could use simple online tools to validate xml files against a single schema. But if we have more than one schema files, which are sub schemas of the base schema,  needed to validate a single xml file, we could use some other  tools which are availble freely.
I used libxml which works better. But for windows-64 bit platform, binary distribution is not available. We need to compile the source files. For linux, compilation would be easy.

Run xmllint from the "bin" folder

# xmllint --noout --schema <BASE_XSD_FILE>  <XML_FILE_TO_BE_VALIDATED>

If there are any errors it will be shown in the command prompt.

Monday, November 26, 2012

Configuring wso2esb to pass messages through proxy server

Organizations may expose the services over a proxy server for several purposes. In such a case, when user configures ESB, he has to provide proxy server configurations.
In axis2 configuration , at the transport sender configuration two properties has to be provided.
  • http.proxyHost : Proxy server's IP
  • http.proxyPort : Prosy server's port
eg :
 <transportSender name="http" class="org.apache.synapse.transport.nhttp.HttpCoreNIOSender">
        <parameter name="non-blocking" locked="false">true&lt;/parameter>
        <parameter name="http.proxyHost" locked="false">192.168.0.26  </parameter>
        <parameter name="http.proxyPort" locked="false">3128</parameter>
 </transportSender>
And a property (POST_TO_URI) has to be set in the synapse configuration to make ESB's out going URL a complete URL.

eg:
<inSequence>
    <property name="POST_TO_URI" value="true" scope="axis2"/>
    <send>
        <endpoint>
            <address uri="http://192.168.0.26:9000/services/SimpleStockQuoteService"/>
        </endpoint>
    </send>
</inSequence>
Depends on the proxy server's behaviour we may need to set some additional properties.
  • DISABLE_CHUNKING : If the proxy server doesn't support HTTP chunking. 
<property name="DISABLE_CHUNKING" value="true" scope="axis2"/>
  • FORCE_HTTP_1.0 : If proxy server supports only HTTP/1.0 messages.
<property name="FORCE_HTTP_1.0" value="true" scope="axis2"/>
 These properties can be applied to WSO2API Manager as well, since WSO2ESB is used as the gateway for APIManager.