Use ASPECTJTOOLS framework to implement the logging function in the Java class library
Use ASPECTJTOOLS framework to implement the logging function in the Java class library
In Java development, log records are a very important function that can help developers to better track and debug the program operation information.The common log record method is achieved by using log library in the code, such as log4j or SLF4J.However, in order to better manage and maintain the log records in the code, we can use the aspectjtools framework to achieve the logging function based on the cut -off -based logging.
ASPECTJTOOLS is a tool that is woven into the cut surface when compiling Java. It can insert additional code to the target class method to enhance the method.Using ASPECTJTOOLS to implement the logging function, the logic logic of the log record can be separated from the business logic, making the code more modular and maintainable.
Below is a sample code that uses aspectjtools to implement logging functions:
1. First, we need to add ASPECTJTools to the project.The following dependencies can be added to Maven:
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.9.7</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjtools</artifactId>
<version>1.9.7</version>
</dependency>
2. Create a cut type to define logic logic.For example, we can create a cut surface called LOGGERASPECT:
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
@Aspect
public class LoggerAspect {
@Pointcut("execution(* com.example.*.*(..))")
private void allMethods() {}
@Before("allMethods()")
public void beforeMethodExecution(JoinPoint joinPoint) {
System.out.println ("Starting execution method:" + Joinpoint.getsignature (). Getname ());
}
@AfterReturning(
pointcut = "allMethods()",
returning = "result")
public void afterMethodExecution(JoinPoint joinPoint, Object result) {
System.out.println ("Execution method end:" + Joinpoint.getSignature (). Getname ());
System.out.println ("Method Return Value:" + Result);
}
}
In the above code, we use the @Aspect annotation to mark the loggerAspect class as a cut type.Then, we use the @PointCut annotation to define an entry point, specify the method we want to intercept. Here we specify the method under all com.example.
Then, we use the @BeFore annotation to insert logical logic of the log record before the method executes.In this example, we simply print the method name.
Finally, we use the @aFTERRETURNING annotation to insert the logic of the log record after the method executes.In this example, we printed the method name and return value.
3. Use our cutting classes in the main program, and enable the compilation function of ASPECTJTOOLS:
import org.aspectj.bridge.AbortException;
import org.aspectj.tools.ajc.Main;
public class MainProgram {
public static void main(String[] args) {
String[] ajcArgs = {"-argfile", "aspectj.txt"};
Main ajc = new Main();
ajc.runMain(ajcArgs, false);
try {
ajc.runMain(ajcArgs, false);
} catch (AbortException e) {
e.printStackTrace();
}
FunctionClass functionClass = new FunctionClass();
functionClass.sampleMethod();
}
}
In this code, we first compile our cut classes through the main class of Aspectjtools.A aspectj.txt file is used here to specify the compiled parameter.
Then, we created an instance of the FunctionClass class and called the SampleMethod method.According to the entry point defined in the cutting classes before, this method will be intercepted and automatically inserted the logic of the log record.
Through the above steps, we successfully realized the logging function in the Java library using the Aspectjtools framework.Through ASPECTJTOOLs, we can decompose logical logic and business logic to make the code clearer and easy to maintain.This method can also be applied to the implementation of other surface -cut functions, such as performance monitoring and transaction management.
