pxb1988/dex2jar · error · RuntimeException

can't convert [ ] to type

Error message

can't convert [${value}] to type ${type}

What it means

convert() maps a raw command-line string to a typed field value; for enum-typed options it does Enum.valueOf(type, value) and, on any failure (bad constant, wrong type), throws a RuntimeException with this message. It is dex2jar's generic 'this option value is not valid for the target type' error.

Solutions

1. Use the exact enum constant name with correct casing for that option
2. Run the tool with -h/--help to list allowed values for the option
3. Check the enum type named in the message (e.g. class com...Level) and pick one of its constants
4. If scripting, match values against the enum in your wrapper script

Example fix

// before
./d2j-dex2jar.sh -f app.apk --log-level verbose
// after
./d2j-dex2jar.sh -f app.apk --log-level DEBUG

// validate enum option value before invoking
def validEnum(type, value) {
  try { Enum.valueOf(type, value); return true } catch (e) { return false }
}
assert validEnum(com.googlecode.dex2jar.tools.Level.class, "DEBUG")

try {
  tool.doMain(args);
} catch (RuntimeException e) {
  if (e.getMessage() != null && e.getMessage().startsWith("can't convert [")) {
    System.err.println("Bad option value; run with -h for allowed values");
  } else throw e;
}

When it happens

Trigger: Passing a CLI option whose declared field is an enum type but whose value does not match any enum constant name (exact, case-sensitive match required), e.g. --log-level verbose when the enum defines only ERROR/WARN/INFO/DEBUG.

Common situations: Typo or wrong casing of enum constants; using a human-friendly value like 'warn' instead of 'WARN'; passing a number for an enum option; changes in enum constants between dex2jar versions.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• ERROR: Unrecognized option
• ERROR: Option need an argument value
• ERROR: Options: is required
• -cv,--class-version out of range, 1-18 is supported.
• version not support yet!

AI-assisted analysis of pxb1988/dex2jar@b5bda4fb49 (2026-09-08). Data as JSON: /api/errors/78ac3b69dc69a236. Report an issue: GitHub.

Appendix: source

Thrown at d2j-base-cmd/src/main/java/com/googlecode/dex2jar/tools/BaseCmd.java:279

        if (type.equals(double.class) || type.equals(Double.class)) {
            return Double.parseDouble(value);
        }
        if (type.equals(boolean.class) || type.equals(Boolean.class)) {
            return Boolean.parseBoolean(value);
        }
        if (type.equals(File.class)) {
            return new File(value);
        }
        if (type.equals(Path.class)) {
            return new File(value).toPath();
        }
        try {
            type.asSubclass(Enum.class);
            return Enum.valueOf(type, value);
        } catch (Exception ignored) {
        }

        throw new RuntimeException("can't convert [" + value + "] to type " + type);
    }

    protected abstract void doCommandLine() throws Exception;

    public void doMain(String... args) {
        try {
            initOptions();
            parseSetArgs(args);
            doCommandLine();
        } catch (HelpException e) {
            String msg = e.getMessage();
            if (msg != null && msg.length() > 0) {
                System.err.println("ERROR: " + msg);
            }
            usage();
        } catch (Exception e) {
            e.printStackTrace(System.err);
        }

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