如果没有 -javaagent 参数，AspectJ 不会运行

Question

我正在尝试在一个简单的 java 应用程序中使用 AspectJ，而不使用 Spring。 项目由maven控制。

这是项目代码，你也可以在GitHub上看到它

App.java

package ge.jibo.aspectj;

public class App {
    public static void main(String[] args) {
        App app = new App();
        app.print("Message from App object...");
    }

    public void print(String value) {
        System.out.println(value);
    }
}

LoggerAspect.java

package ge.jibo.aspectj;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;

@Aspect
public class LoggerAspect {

    @Around("execution(!static * *(..))")
    public Object dontLogDuplicates(ProceedingJoinPoint thisJoinPoint) throws Throwable {
        System.out.println("Message from LoggerAspect object");
        return thisJoinPoint.proceed();
    }
}

aop.xml 在 resources\META-INF 目录中

<?xml version="1.0" encoding="UTF-8"?>
<aspectj>
    <aspects>
        <aspect name="ge.jibo.aspectj.LoggerAspect"/>
    </aspects>
    <weaver options="-verbose -showWeaveInfo">
        <include within="ge.jibo.aspectj..*"/>
    </weaver>
</aspectj>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>ge.jibo.aspectj</groupId>
    <artifactId>aspectj-demo</artifactId>
    <version>1.0</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.9.6</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.1</version>
                    <configuration>
                        <source>${maven.compiler.source}</source>
                        <target>${maven.compiler.target}</target>
                    </configuration>
                </plugin>
                <plugin>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>3.0.2</version>
                    <configuration>
                        <archive>
                            <index>true</index>
                            <manifest>
                                <mainClass>ge.jibo.aspectj.App</mainClass>
                            </manifest>
                        </archive>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

在生成mvn installJAR 文件之后，我尝试使用java -jar aspectj-demo.jar 命令执行JAR，但只执行App 对象，LoggerAspect 不打印任何内容。

如果我将带有aspectjweaver-1.9.6.jar 的-javaagent 参数传递给JVM，则执行Aspect 对象。

• 如何避免每次都传递这个-javaagent 参数？
• 我应该在pom.xml中添加一些插件来直接执行方面吗？

Answer 1

一个简单的解决方案/解决方法是添加 aspectj-maven-plugin 用于编译时编织（在这种情况下 aop.xml 文件不再需要）

并使用 maven-assembly-plugin 将项目及其依赖项打包到可执行 jar 中（还有其他方法可以使用 libs/dependencies 打包可执行 jar）

pom.xml

<build>
    <finalName>${project.artifactId}</finalName>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>aspectj-maven-plugin</artifactId>
            <version>1.11</version>
            <configuration>
                <verbose>true</verbose>
                <complianceLevel>1.8</complianceLevel>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                    <configuration>
                        <source>${maven.compiler.source}</source>
                        <target>${maven.compiler.target}</target>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>single</goal>
                    </goals>
                    <configuration>
                        <archive>
                            <manifest>
                                <mainClass>
                                    ge.jibo.aspectj.App
                                </mainClass>
                            </manifest>
                        </archive>
                        <descriptorRefs>
                            <descriptorRef>jar-with-dependencies</descriptorRef>
                        </descriptorRefs>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

执行mvn install会生成额外的jar文件aspectj-demo-jar-with-dependencies.jar

java -jar aspectj-demo-jar-with-dependencies.jar