pinpoint-apm/pinpoint · error · InstrumentException

ClassReader fail, classFile=

Error message

ClassReader fail, classFile=

What it means

toMainClassByteArray reads the bundled InterceptorHolder.class template from the profiler classloader and rewrites it with ASM. This InstrumentException wraps an IOException from readClass — either the template resource was not found on the classpath (InputStream null) or the class bytes failed to be parsed by ASM's ClassReader (corrupted resource).

Solutions

1. Verify the profiler jar contains InterceptorHolder.class at the exact package path (jar tf)
2. Re-download/re-extract the Pinpoint agent distribution to fix a corrupted jar
3. Check getCause(): 'not found class ...' means missing resource; a format error means ASM/JDK version mismatch
4. If shading the agent, keep the template resource and matching ASM dependency in the shaded artifact

// verify template resource before generating bytes
String tpl = "com/navercorp/pinpoint/profiler/instrument/interceptor/InterceptorHolder.class";
if (ASMInterceptorHolder.class.getClassLoader().getResourceAsStream(tpl) == null) {
    throw new IllegalStateException("missing profiler template resource: " + tpl);
}

try {
    holder.defineClass(classLoader);
} catch (InstrumentException e) {
    if (e.getCause() instanceof IOException) {
        logger.error("template read failed — profiler jar corrupt or mis-shaded: {}", e.getMessage());
    }
}

When it happens

Trigger: Calling toMainClassByteArray (via defineClass/build) when com/navercorp/pinpoint/profiler/instrument/interceptor/InterceptorHolder.class is absent from the agent classpath or its bytes are corrupt/incompatible with the bundled ASM ClassReader.

Common situations: Broken shading/relocation of the profiler jar by a downstream packager, an incomplete agent deployment, or mixing ASM versions so ClassReader rejects a newer class-file version.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• @Aspect not found. adviceClass=
• defineClass fail
• invalid class hierarchy. source class=
• No methods are intercepted. target
• No methods are intercepted. target

AI-assisted analysis of pinpoint-apm/pinpoint@744c3d3075 (2026-09-07). Data as JSON: /api/errors/e06989a205cdd7fc. Report an issue: GitHub.

Appendix: source

Thrown at agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/instrument/ASMInterceptorHolder.java:160

            final Class<?> mainClass = InterceptorDefineClassHelper.defineClass(classLoader, className, mainClassBytes);
            final byte[] innerClassByte = toInnerClassByteArray();
            InterceptorDefineClassHelper.defineClass(classLoader, innerClassName, innerClassByte);
            return mainClass;
        } catch (Exception e) {
            throw new InstrumentException("defineClass fail", e);
        }
    }

    byte[] toMainClassByteArray() throws InstrumentException {
        try {
            ClassNode classNode = readClass(INTERCEPTOR_HOLDER_CLASS);
            final ClassWriter classWriter = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
            final ClassVisitor renameClassAdapter = new RenameClassAdapter(classWriter, className);
            classNode.accept(renameClassAdapter);
            return classWriter.toByteArray();
        } catch (IOException e) {
            // read fail
            throw new InstrumentException("ClassReader fail, classFile=" + INTERCEPTOR_HOLDER_CLASS, e);
        }
    }

    byte[] toInnerClassByteArray() throws InstrumentException {
        try {
            ClassNode classNode = readClass(INTERCEPTOR_HOLDER_INNER_CLASS);
            final ClassWriter classWriter = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
            final ClassVisitor renameClassAdapter = new RenameInnerClassAdapter(classWriter, className);
            classNode.accept(renameClassAdapter);
            return classWriter.toByteArray();
        } catch (IOException e) {
            // read fail
            throw new InstrumentException("ClassReader fail, classFile=" + INTERCEPTOR_HOLDER_INNER_CLASS, e);
        }
    }

    ClassNode readClass(String classFileName) throws IOException {
        final ClassLoader classLoader = ASMInterceptorHolder.class.getClassLoader();

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