Programming Groovy 2

15.3 Review of MOP Techniques

We’ve seen a number of options to intercept, inject, and synthesize methods. In this section, we’ll figure out which option is right for us.

Options for Method Interception

We discussed method interception in Chapter 12, ​Intercepting Methods Using MOP​, and Section 13.1, ​Injecting Methods Using Categories​. We can use ​GroovyInterceptable​, ​ExpandoMetaClass​, or categories.

If we have the privileges to modify the class source, we can implement ​GroovyInterceptable​ on the class we want to intercept method calls. The effort is as simple as implementing ​invokeMethod​ .

If we can’t modify the class or if the class is a Java class, then we can use ​ExpandoMetaClass​ or categories. ​ExpandoMetaClass​ clearly ...