Use the "Mirror" framework in the Java library to achieve dynamic proxy technology
Use the "Mirror" framework in the Java library to achieve dynamic proxy technology
Dynamic proxy is a commonly used software design mode that allows the method of creating proxy objects and intercepting target objects during runtime.In Java, the "Mirror" framework can be used to achieve dynamic proxy technology, which provides an easy -to -use API to generate proxy objects.
The Mirror framework is a lightweight Java class library that realizes dynamic proxy by using AOP (programming programming) ideas.It encapsulates Java's native dynamic proxy API and provides a more intuitive and concise way to achieve proxy objects.
Below is an example code that uses the Mirror framework to implement dynamic proxy technology:
First of all, we need to define an interface. This interface contains the method we want to intercept:
public interface UserService {
void save();
void delete();
}
Then, we need to create a target object to achieve this interface:
public class UserServiceImpl implements UserService {
@Override
public void save() {
System.out.println ("Save user information");
}
@Override
public void delete() {
System.out.println ("Delete user information");
}
}
Next, we use the Mirror framework to create a proxy object, and the method of intercepting the target object:
public class UserServiceProxy implements MethodInterceptor {
private UserService target;
public UserServiceProxy(UserService target) {
this.target = target;
}
public UserService createProxy() {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(UserServiceImpl.class);
enhancer.setCallback(this);
return (UserService) enhancer.create();
}
@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
System.out.println ("Starting execution method:" + Method.getName ());
Object result = method.invoke(target, args);
System.out.println ("Method executes:" + Method.getName ());
return result;
}
}
In the above code, we implemented the METHODINTERCEPTOR interface and rewritten the intercept method.In the Internet method, we can add additional logic before and after the method call.
Finally, we can use the proxy object to call the target object method to achieve the effect of dynamic proxy:
public class Main {
public static void main(String[] args) {
UserService target = new UserServiceImpl();
UserServiceProxy proxy = new UserServiceProxy(target);
UserService userService = proxy.createProxy();
userService.save();
userService.delete();
}
}
In the above code, we first created an UserService object as the target object, and then created a proxy object through UserServiceProxy.Finally, we can call the target object through the proxy object.
Run the above code, and the output will be:
Start execution method: save
Save user information
Method execution: SAVE
Start execution method: delete
Delete user information
Method execution: delete
This is the basic step of using the Mirror framework in the Java library to achieve dynamic proxy technology.Through the Mirror framework, we can simplify the implementation process of dynamic proxy, and flexibly intercept and expand the method of the target object.
