The strategy design pattern dynamically chooses an implementation algorithm, a strategy, at runtime. The pattern can be used to select different business algorithms depending on the circumstances.

We could define different algorithm implementations as separate classes. Or we make use of Java SE 8 lambdas and functions, that serve as lightweight strategy implementation here.

CDI is capable of injecting parameterized types:

public class Greeter {

 @Inject
 Function<String, String> greetingStrategy;

 public String greet(String name) {
 return greetingStrategy.apply(name);
 }
}

A CDI producer creates and exposes the greeting depending on the dynamic logic. The actual strategy is represented by the Function type and being selected dynamically:

public class GreetingStrategyExposer {

 private final Function<String, String> formalGreeting = name -> "Dear " + name;
 private final Function<String, String> informalGreeting = name -> "Hey " + name;

 @Produces
 public Function<String, String> exposeStrategy() {
 // select a strategy
 ...
 return strategy;
 }
}