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我正在嘗試學習儀器以添加變形器,removeTransformer和reTransformer。儀器removeTransformer在不同線程中不工作
我試圖添加變壓器,它運作良好。
當我添加變壓器後,如下圖所示,除去變壓器,它也很好。
public static void premain(String agentArgs, Instrumentation instrumentation) {
ClassFileTransformer transformer = new ClassFileTransformer() {
public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
if (!className.contains("Test")) {
return classfileBuffer;
}
ClassReader cr = new ClassReader(classfileBuffer);
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
cr.accept(new FieldAdapter(cw, new FieldNode(ASM5, Opcodes.ACC_PRIVATE, "hello", Type.getDescriptor(String.class), "test", "first")), 0);
return cw.toByteArray();
}
};
instrumentation.addTransformer(transformer, true);
instrumentation.removeTransformer(transformer);
}
但是,當我試圖在不同線程中移除變壓器時,它不起作用。
public static void premain(String agentArgs, Instrumentation instrumentation) {
ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
ClassFileTransformer transformer = new ClassFileTransformer() {
public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
if (!className.contains("Test")) {
return classfileBuffer;
}
ClassReader cr = new ClassReader(classfileBuffer);
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
cr.accept(new FieldAdapter(cw, new FieldNode(ASM5, Opcodes.ACC_PRIVATE, "hello", Type.getDescriptor(String.class), "test", "first")), 0);
return cw.toByteArray();
}
};
instrumentation.addTransformer(transformer, true);
executor.scheduleAtFixedRate(new RemoveTransform(instrumentation, transformer), 3, 10, TimeUnit.SECONDS);
}
static class RemoveTransform implements Runnable {
private Instrumentation instrumentation;
private ClassFileTransformer classFileTransformer;
public RemoveTransform(Instrumentation instrumentation, ClassFileTransformer classFileTransformer) {
this.instrumentation = instrumentation;
this.classFileTransformer = classFileTransformer;
}
public void run() {
System.out.println("removed transform.....");
instrumentation.removeTransformer(classFileTransformer);
}
}
我檢查了輸出,我肯定是移除變壓器執行的線程。
你的意思是我必須重新轉換添加inteceptor的類? –
這是正確的。 –
但是在添加'instrumentation.retransformClasses(Test.class);'removeTransformer之後它仍然不起作用?你有一個演示與我分享? –