pxb1988/dex2jar · error · DexException

while accept parameter annotation in method

Error message

while accept parameter annotation in method:%s.

What it means

DexException wrapping any failure that occurs while DexFileReader.accept(DexMethodVisitor) reads and dispatches a method's parameter annotations from the dex file's parameter-annotation table. The original cause is preserved as the exception cause; the message identifies which method's annotations failed to decode.

Solutions

1. Inspect the wrapped cause (e.getCause()) to find the underlying decode failure
2. Verify the dex file with dexdump/dexlint to confirm the annotation section is intact
3. Rebuild the dex/apk with the standard dx/d8 toolchain before converting
4. If the dex is known-bad, skip parameter annotations via config options or catch DexException around accept()

Example fix

// before
reader.accept(dmv);
// after
try {
    reader.accept(dmv);
} catch (DexException e) {
    log.warn("bad parameter annotations for dex", e.getCause());
}

// Validate dex before conversion
DexFileReader r = new DexFileReader(dexBytes);
// optionally run dexdump -d classes.dex externally and fail on errors

try {
    reader.accept(dmv);
} catch (DexException e) {
    logger.warn("parameter annotations unreadable", e.getCause());
}

When it happens

Trigger: Calling accept() on a DexFileReader whose dex file has a corrupt or truncated parameter_annotations entry, or an annotation set ref list offset that points outside the file, causing read_annotation_set_ref_list to throw.

Common situations: Processing a dex file produced by a non-standard toolchain, an obfuscator or packer that rewrites annotation offsets, or a truncated/corrupted classes.dex inside an APK.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• While accepting parameter annotation in parameter
• Encountered RESTART_LOCAL on new v
• while accept code in method
• while accept method:[ ]
• jump out of insns -> %04x

AI-assisted analysis of pxb1988/dex2jar@b5bda4fb49 (2026-09-08). Data as JSON: /api/errors/a5d821d34d240e2b. Report an issue: GitHub.

Appendix: source

Thrown at dex-reader/src/main/java/com/googlecode/d2j/reader/DexFileReader.java:1050

        try {
            DexMethodVisitor dmv = cv.visitMethod(method_access_flags, method);
            if (dmv != null) {
                if ((config & SKIP_ANNOTATION) == 0) {
                    Integer annotation_offset = methodAnnos.get(method_id);
                    if (annotation_offset != null) {
                        try {
                            read_annotation_set_item(annotation_offset, dmv);
                        } catch (Exception e) {
                            throw new DexException(e, "while accept annotation in method:%s.", method.toString());
                        }
                    }
                    Integer parameter_annotation_offset = parameterAnnos.get(method_id);
                    if (parameter_annotation_offset != null) {
                        try {
                            read_annotation_set_ref_list(parameter_annotation_offset, dmv);
                        } catch (Exception e) {
                            throw new DexException(e, "while accept parameter annotation in method:%s.",
                                    method.toString());
                        }
                    }
                }
                if (code_off != 0) {
                    boolean keep = true;
                    if (0 != (SKIP_CODE & config)) {
                        keep = 0 != (KEEP_CLINIT & config) && method.getName().equals("<clinit>");
                    }
                    if(keep) {
                        DexCodeVisitor dcv = dmv.visitCode();
                        if (dcv != null) {
                            try {
                                acceptCode(code_off, dcv, config, (method_access_flags & DexConstants.ACC_STATIC) != 0,
                                        method);
                            } catch (Exception e) {
                                throw new DexException(e, "while accept code in method:[%s] @%08x", method.toString(),
                                        code_off);

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