Aspectj weaver framework profile and how to use
Aspectj weaver framework profile and how to use
ASPECTJ Weaver is an AOP (facing -oriented programming) framework based on Java programming language. It provides a rich set of grammar and tools to introduce and use the concept of cutting programming in Java applications.Aspectj Weaver allows developers to separate attention points from the main business logic and join the application in a modular manner to provide higher -level reuse and maintenance.
The core of ASPECTJ Weaver is Aspectj programming language. It expands the Java language and adds some new keywords and grammar to achieve the function of cutting programming.Aspectj weaver inserts the cutting surface code into the target program by static weaving or runtime.Static knitting is performed during compilation, and it modifies the source code to introduce the cut surface and generate the modified bytecode file.During the runtime, the application is carried out during the application. It inserted the cutting surface code into the target program class through the JVM dynamic class loading mechanism.
The following is an example of a simple Aspectj Weaver, which shows the function of how to use cut -off programming to implement log records:
// Define the cutting surface
public aspect LoggingAspect {
// Define the cut point, indicating that the objective method needs to be knitted
pointcut logMethodExecution() : execution(* com.example.*.*(..));
// Definition notification, indicating the logic that needs to be executed before and after the goal method execution
before() : logMethodExecution() {
System.out.println("Method Execution Started!");
}
after() : logMethodExecution() {
System.out.println("Method Execution Finished!");
}
}
// Define business category
public class MyClass {
public void doSomething() {
System.out.println("Doing something...");
}
}
In the above examples, we define a cut -sized type `Loggingaspect`, which contains a cut point` logmethodexecution () and two notifications `beFore () and` after () `.Cut the point `logmethodexecution ()` uses the expression `executionAll methods of all classes.Notification `Before () and` After () `Output log information before and after execution of the target method, respectively.
When using ASPECTJ Weaver, we need to add the ASPECTJ compiler and ASPECTJ to the construction path of the project, and configure the compilation parameters to specify the settings of ASPECTJ.Then, when compiling or running the application, the Aspectj Weaver will be woven or runtime according to the definition of the cut surface.
By introducing Aspectj weaver, developers can use cutting surface programming to achieve various functions, such as log records, performance monitoring, transaction management, etc., thereby improving the quality and maintenance of the application.
