The Java Call out policy provides a way to inject any custom Java modules as part of the message flow. The call out handler needs to implement a Java interface to which complete processing context is passed.
Configuration
The properties that have to be configured to use the policy are described below.
Figure 1: Java Call Out Policy Configuration attributes
Qualified Class Name
The fully qualified name of the class which implements the interface CallOutProcessor.
Location of Jar File
The jar file which has the class name. The same jar location must be added to configuration of gateway servers.. Navigate to FIORANO_HOME > esb > server > bin. Add path(location) of the jar in server.conf file under tag <java.classpath>.
Is Streaming Supported
The option can be checked if the class does not access or modify the payload and only works with parameters and context variables.
Accessing Processor Context
The method process has the variable processor context whose methods are listed below. The methods can be used to access or modify the message.
Example
The following class demonstrates the use of Java call out. The class inspects the parameter ID and if the details corresponding to ID are present in a local database. If present, the details are set as payload and a flag RETRIEVED_FROM_DB will be set so that other policies' execution can be controlled by rules based on this flag.