Difference between factory mode and strategy mode

Same as ：

On the pattern structure , The two are very similar

 

different ：

1. Factory is a creation mode , Its purpose is to create objects , According to the transmission parameters , Create different objects , The method of using an object after it is created
    Strategy is a behavioral model , Its function is to let an object choose a behavior among many behaviors

2. Create a focus object , A focus behavior encapsulation

3. The factory parameter is a type , Policy parameter transfer is a new object

summary ：

What the factory model can do , Strategic models can do . What the strategic model can do , Factory mode can also do , It just gets troublesome . because , Factory mode is mainly the instantiation object of the returned interface implementation class , Then call the method of the object , The policy pattern object is created when the policy pattern is instantiated , We You can freely splice and rewrite methods in the policy pattern , The factory model is regardless of the splicing of these methods , He only focuses on the final result , Don't pay attention to the process , Only instantiated objects are returned at a time , Then call the object's methods again , The strategic model focuses on the process .

Applicable scenarios ：

Factory pattern is a creative design pattern , It takes orders , Create the required instance ; The main solution is the unified distribution of resources , Independent creation of objects , Let the creation of objects have nothing to do with specific customers . Main application in multi database selection , Class library file loading, etc .

The policy mode is used to solve the problem of policy switching and extension , More succinctly, define the policy family , Separately encapsulated , So that they can replace each other , The strategy pattern makes the strategy change independent of the customers who use the strategy .

Add ：

Policy mode and Microservices ：

The policy pattern is very similar to microservices , For example, we write 3 Interface , Eating is a micro service , Running is a micro service , Dressing is a micro service . The purpose of the strategy model is to connect various methods , Reach a new way , The purpose of microservices is to prevent multiple calls of services , Reduce code coupling , So it seems that the policy mode is similar to the microservice