9.4. Operation Selectors
9.4.1. Operation Selector
Use the
OperationSelector to determine which service operation should be invoked for the message exchange.
9.4.2. Types of Operation Selectors
SwitchYard provides the following options for Operation Selectors.
Important
Operation selectors are used in combination with a service binding to help SwitchYard determine the target operation for a service invocation. When a service only has a single operation, an operation selector should not be used. If an operation selector is used for a service with a single operation, failure to assign an operation in the operation selector will not result in an error. If an operation selector fails to assign an operation for a service with multiple operations an error is reported.
- Static Operation Selector
- You can specify an operation name in the configuration. Here is what a Static Operation Selector configuration looks like:
<hornetq:binding.hornetq> <swyd:operationSelector operationName="greet" xmlns:swyd="urn:switchyard-config:switchyard:1.0"/> (... snip ...) </hornetq:binding.hornetq> - XPath Operation Selector
- You can specify an XPath location which contains an operation name to be invoked in the message contents. Here is what an XPath Operation Selector configuration looks like:
<jca:binding.jca> <swyd:operationSelector.xpath expression="//person/language" xmlns:swyd="urn:switchyard-config:switchyard:1.0"/> (... snip ...) </jca:binding.jca>For this configuration, if you specify the following message content, then the operationspanish()is invoked:<person> <name>Fernando</name> <language>spanish</language> </person> - Regex Operation Selector
- You can specify a regular expression to find an operation name to be invoked in the message contents. Here is what a Regex Operation Selector configuration looks like:
<http:binding.http> <swyd:operationSelector.regex expression="[a-zA-Z]*Operation" xmlns:swyd="urn:switchyard-config:switchyard:1.0"/> (... snip ...) </http:binding.http>For this configuration, if you specify the following message content, then the operationregexOperation()is invoked:xxx yyy zzz regexOperation aaa bbb ccc
- Java Operation Selector
- You can specify a Java class which is able to determine the operation to be invoked. Here is what a Java Operation Selector configuration looks like:
<jca:binding.jca> <swyd:operationSelector.java class="org.switchyard.example.MyOperationSelectorImpl" xmlns:swyd="urn:switchyard-config:switchyard:1.0"/> (... snip ...) </jca:binding.jca>Here, theorg.switchyard.example.MyOperationSelectorImplhas to implementorg.switchyard.selector.OperationSelectoror be a subclass of concrete OperationSelector classes for each service bindings. You can override theselectOperation()method as you like.Following are the default OperationSelector implementation for each service bindings:- Camel :
org.switchyard.component.camel.selector.CamelOperationSelector - JCA/JMS :
org.switchyard.component.jca.selector.JMSOperationSelector - JCA/CCI :
org.switchyard.component.jca.selector.CCIOperationSelector - HTTP :
org.switchyard.component.http.selector.HttpOperationSelector
