java - AspectJ 的 NoSuchMethodError

Question

注意:这是概念实现的证明，而不是最终结果。

我有第三个。派对附加组件，我想限制他们对声音的使用，例如限制持续时间等(安全管理器不可能)。为了实现这一点，我考虑用包装器替换 AudioSystem.getLine() 的返回。
这是测试方面:

@Aspect
public class MixerAspect {
    @Around("execution(* javax.sound.sampled.AudioSystem.getLine(javax.sound.sampled.Line.Info))")
    public Object getLineAdvice(ProceedingJoinPoint pjp) throws Throwable {
        System.out.println("AspectJ");
        pjp.getArgs();
        Line ret = (Line) pjp.proceed();
        return ret;
    }
}

每个附加组件都有自己的类加载器，它们通常不共享对象，所以这就是我想出的:

@Override
public Class<?> loadClass(String className) throws ClassNotFoundException {
....
if (className.equals(AudioSystem.class.getName())) {
    .....
    byte[] array = buffer.toByteArray();
        try {
            if (mixed == null)
                mixed = weaver.defineClass(className, array, new CodeSource(mixerAspect, (CodeSigner[]) null));
            return mixed;
        } catch (IOException e) {
            throw new ClassNotFoundException("unable to define class", e);
        }

这是 WeavingURLClassloader 的初始化代码:

weaver = new WeavingURLClassLoaderHelper(new URL[0], parent);
weaver.addURL(aspects[0]);

parent 是可以访问 Mixer 方面的类加载器，方面是一个 url 数组，其中只有一个元素指向 MixerAspect 所在的目录。
我的 aop.xml:

<aspectj>
    <aspects>
        <aspect name="org.intellimate.izou.security.replaced.MixerAspect"/>
    </aspects>

    <weaver options="-Xset:weaveJavaxPackages=true -verbose -showWeaveInfo -debug">
        <!-- Weave types that are within the javax.* or org.aspectj.*
             packages. Also weave all types in the foo package that do
             not have the @NoWeave annotation. -->
        <include within="javax.*"/>
        <include within="org.intellimate.izou.security.replaced.*"/>
        <include within="javax.sound.sampled.AudioSystem"/>
    </weaver>
</aspectj>

这是(相关)日志:

....(no relevant log)
TraceFactory.instance=org.aspectj.weaver.tools.Jdk14TraceFactory@53aad5d5
[WeavingURLClassLoaderHelper] info AspectJ Weaver Version 1.8.5 built on Thursday Jan 29, 2015 at 01:03:58 GMT
[WeavingURLClassLoaderHelper] info register classloader ro.fortsoft.pf4j.IzouPluginClassLoader$WeavingURLClassLoaderHelper
[WeavingURLClassLoaderHelper] info using configuration /Users/LeanderK/IdeaProjects/Izou/target/classes/META-INF/aop.xml
[WeavingURLClassLoaderHelper] info register aspect org.intellimate.izou.security.replaced.MixerAspect
[WeavingURLClassLoaderHelper] info AspectJ Weaver Version 1.8.5 built on Thursday Jan 29, 2015 at 01:03:58 GMT
[WeavingURLClassLoaderHelper] info register classloader ro.fortsoft.pf4j.IzouPluginClassLoader$WeavingURLClassLoaderHelper
[WeavingURLClassLoaderHelper] info using configuration /Users/LeanderK/IdeaProjects/Izou/target/classes/META-INF/aop.xml
[WeavingURLClassLoaderHelper] info register aspect org.intellimate.izou.security.replaced.MixerAspect
...(no relevant log)
[WeavingURLClassLoaderHelper] debug weaving 'javax.sound.sampled.AudioSystem'
[WeavingURLClassLoaderHelper] weaveinfo Join point 'method-execution(javax.sound.sampled.Line javax.sound.sampled.AudioSystem.getLine(javax.sound.sampled.Line$Info))' in Type 'javax.sound.sampled.AudioSystem' (AudioSystem.java:410) advised by around advice from 'org.intellimate.izou.security.replaced.MixerAspect' (MixerAspect.class(from MixerAspect.java))
[WeavingURLClassLoaderHelper] debug generating class 'javax.sound.sampled.AudioSystem$AjcClosure1'
2015-05-24 20:12:13,945 FATAL [Thread-5] org.intellimate.izou.threadpool.ThreadPoolManager (ThreadPoolManager.java:59) - unable to provide callback for: org.intellimate.izou.addon.AddOnManager$$Lambda$19/970865974@1f4f3b69
java.util.concurrent.CompletionException: java.lang.NoSuchMethodError: org.intellimate.izou.security.replaced.MixerAspect.aspectOf()Lorg/intellimate/izou/security/replaced/MixerAspect;
    at java.util.concurrent.CompletableFuture.internalComplete(CompletableFuture.java:205) [?:1.8.0_25]
    at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:459) [?:1.8.0_25]
    at java.util.concurrent.CompletableFuture$Async.run(CompletableFuture.java:428) [?:1.8.0_25]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_25]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_25]
    at org.intellimate.izou.threadpool.ThreadPoolManager$LoggingThreadFactory$1.run(ThreadPoolManager.java:73) [classes/:?]
Caused by: java.lang.NoSuchMethodError: org.intellimate.izou.security.replaced.MixerAspect.aspectOf()Lorg/intellimate/izou/security/replaced/MixerAspect;
    at javax.sound.sampled.AudioSystem.getLine(AudioSystem.java:410) ~[?:1.8.0_25]
    at leanderk.izou.playground.ExampleAddOn.prepare(ExampleAddOn.java:41) ~[?:?]
    at org.intellimate.izou.sdk.addon.AddOn.register(AddOn.java:41) ~[?:?]
    at org.intellimate.izou.addon.AddOnManager$$Lambda$19/970865974.run(Unknown Source) ~[?:?]
    at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:454) ~[?:1.8.0_25]
    ... 4 more

看起来它没有编织，但为什么呢？我不知道还能尝试什么。我有以下依赖项:

<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.8.5</version>
 </dependency>
 <dependency>
    <groupId>aspectj</groupId>
    <artifactId>aspectjrt</artifactId>
    <version>1.5.4</version>
 </dependency>

更复杂的是，类加载器位于另一个项目中，该项目有一个简单的 maven 依赖项。
我缺少某些方面的初始化吗？

编辑以澄清答案:
您还必须通过 WeavingURLClassloader 定义方面，这是我的(示例 - 它的简化)代码，同样可以应用于您想要混合的每个类。在我的情况下，类已经通过系统类加载器加载，所以我不得不明确调用定义(小心，从不同的类加载器加载的相同类是不一样的!)

private Class mixer = null;
......
@Override
public Class<?> loadClass(String className) throws ClassNotFoundException {
   .....
   else if (className.contains("MixerAspect")) {
        InputStream is = this.getResourceAsStream(className.replace('.', '/') + ".class");
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();

        int nRead;
        byte[] data = new byte[16384];

        try {
            while ((nRead = is.read(data, 0, data.length)) != -1) {
                buffer.write(data, 0, nRead);
            }
        } catch (IOException e) {
            throw new ClassNotFoundException("unable to load class", e);
        }

        try {
            buffer.flush();
        } catch (IOException e) {
            throw new ClassNotFoundException("unable to load class", e);
        }
        byte[] array = buffer.toByteArray();
        URL mixerAspect = getResource("org/intellimate/izou/security/replaced/MixerAspect.class");
        try {
            if (mixer == null) {
                mixer = weaver.defineClass(className, array, new CodeSource(mixerAspect, (Certificate[]) null));
            }
            return mixer;
        } catch (IOException e) {
            throw new ClassNotFoundException("unable to define class", e);
        }
    }

Answer 1

如果使用注释样式方面并使用 javac 进行编译，您需要在加载时通​​过编织器本身“完成”方面。如果不这样做，则它无法生成类似 aspectOf() 的辅助方法，这些方法将从其他尝试使用方面的编织类型调用。 NoSuchMethodError 的 aspectOf() 告诉我方面没有被编织。 aspectOf() 被调用的事实告诉我其他类型正在成功编织。几个选择:

使用 ajc 来编译你的 MixerAspect，这将在编译时添加额外的方法

确保您的编织过程可以编织 MixerAspect。确保它加载了正在编织的其他类而不是父加载器？还是让父加载器也进行编织？