[designmode] proxy pattern

Basic introduction

1. The proxy pattern ： Provide a surrogate for an object , To control access to this object . That is, access the target object through the proxy object . The advantage of this is : It can be realized on the basis of the target object , Enhance additional functional operations , That is, extending the functionality of the target object .

2. The proxied object can be a remote object 、 Create expensive objects or objects that need security control

3. There are different forms of agency , There are three main types Static proxy 、 The reason is A dynamic proxy (JDK agent 、 The interface agent ) and Cglib The reason is agent ( Objects can be created dynamically in memory , Instead of implementing interfaces , He belongs to the category of dynamic agency ) .

1 The proxy pattern (Proxy)

1.1 The basic introduction of agent mode

1. The proxy pattern ： Provide a surrogate for an object , To control access to this object . That is, access the target object through the proxy object . The advantage of this is : It can be realized on the basis of the target object , Enhance additional functional operations , That is, extending the functionality of the target object .

2. The proxied object can be a remote object 、 Create expensive objects or objects that need security control

3. There are different forms of agency , There are three main types Static proxy 、 The reason is A dynamic proxy (JDK agent 、 The interface agent ) and Cglib The reason is agent ( Objects can be created dynamically in memory , Instead of implementing interfaces , He belongs to the category of dynamic agency ) .

4. Schematic diagram of agent mode

2. Static proxy

2.1 The basic introduction of static code pattern

Static agents are used , You need to define an interface or parent class , Proxied object ( That is, the target object ) Implement the same interface or inherit the same parent class with the proxy object