Actions can be used in different ways:
Actions have access to globals and the variables that are defined for the process and the 'kcontext' variable. This variable is of type org.drools.runtime.process.ProcessContext and can be used for
Drools currently supports two dialects: the java and the MVEL dialect. Java actions should be valid Java code. MVEL actions can use the business scripting language MVEL to express the action. MVEL accepts any valid Java code but also provides aditional support for nested accesses of parameters (e.g. person.name instead of person.getName()), and many other scripting improvements. Therefore, MVEL usually allows more business user friendly action expressions. For example, an action that prints out the name of the person in the "requester" variable of the process would look like this:
// using the Java dialect System.out.println( person.getName() ); // Similarly, using the MVEL dialect System.out.println( person.name );