On the technical principles and design thoughts of the NANNING framework in the Java class library
The Nanning framework is an AOP (facing -faced programming) framework for Java libraries. It is based on dynamic proxy technology and aims to provide a simple and flexible way to achieve the function of cross -focusing point.This article will introduce the technical principles and design ideas of the Nanning framework, as well as the complete programming code and related configuration involved.
1. Technical principles
The technical principles of the Nanning framework are mainly based on dynamic proxy, that is, dynamically generate proxy objects during runtime, and handle cross -section attention points through proxy objects.Specifically, the Nanning framework uses the dynamic agent or CGLIB library provided by JDK to achieve the proxy function.
When using the JDK dynamic proxy, the NANNING framework generates an agent object according to the cut surface and entry point defined by the user.When the client calls the method of this proxy object, the corresponding horizontal logic is automatically triggered.For example, a method can be defined in the cut surface, and the log is printed before and after the method execution.
When using CGLIB, the NANNING framework will achieve proxy by creating a subclass of a target class.This subclass inherits all the methods of the target class, and adds horizontal cutting logic before and after the method execution.Compared to the JDK dynamic agent, the CGLIB requires that the target class cannot be fired.
Second, design ideas
The design ideas of the Nanning framework are mainly based on the concept of AOP, and the purpose of separation of business logic and cross -section logic aims to separate business logic.It provides a way to increase the horizontal cutting function without changing the original code.
In the Nanning framework, users can define a cut surface, and the cut surface is a Java class, which defines some horizontal cutting logic, such as log records and performance monitoring.The user can also define the entry point, and the entry point specifies the logic of the application of the cut surface in which method.
The Nanning framework provides a set of annotations to identify the cut surface and entry point. Users only need to add annotations to the corresponding class or method.At the same time, the Nanning framework supports the XML configuration file to define the cutting surface and entry point.
Specific programming code and related configuration are shown below:
1. Define a cut -off class:
public class LoggingAspect {
// Print logs before and after the method execution
public void logBefore() {
System.out.println("Before method execution");
}
public void logAfter() {
System.out.println("After method execution");
}
}
2. Define a method in the target class, and specify the entry point through annotations:
public class UserService {
// Specify the entry point as this method
@NanningAspect(pointcut = "UserService#saveUser")
public void saveUser() {
System.out.println("Saving user");
}
}
3. Define the cutting surface and entry point in the configuration file:
<nanning-config>
<aspect>
<class>com.example.LoggingAspect</class>
</aspect>
<pointcut>
<class>com.example.UserService</class>
<method>saveUser</method>
</pointcut>
</nanning-config>
Through the above code and configuration, the NANNINING framework will call the LogBeFore and LogAFTER method in the Loggingaspect class before and after the execution of the SaveUser method of UserService, so as to implement the logging function.
Summarize:
The Nanning framework is an AOP framework based on dynamic proxy, which achieves horizontal cutting logic by dynamically generating proxy objects.Its design ideas are to separate business logic from cross -cutting logic, and provide annotations and configuration files to define the cutting surface and entry point.Using the NANNING framework can simplify the code to improve the maintenance and scalability of the system.
