java-native-access/jna · error · com.sun.jna.platform.win32.COM.tlb.imp.TlbParameterNotFoundException

Commandline parameter not found: <key>

Error message

Commandline parameter not found: <key>

What it means

TlbCmdlineArgs.getRequiredParam retrieves a command-line parameter and throws TlbParameterNotFoundException when no value exists for the given key. It enforces that mandatory options were supplied to the COM type-library importer. The message names the missing key so you can see which option is absent.

Source

Thrown at contrib/platform/src/com/sun/jna/platform/win32/COM/tlb/imp/TlbCmdlineArgs.java:47

    private static final long serialVersionUID = 1L;

    public TlbCmdlineArgs(String[] args) {
        this.readCmdArgs(args);
    }

    public int getIntParam(String key) {
        String param = this.getRequiredParam(key);
        return Integer.parseInt(param);
    }

    public String getParam(String key) {
        return this.get(key);
    }

    public String getRequiredParam(String key) {
        String param = this.getParam(key);
        if (param == null)
            throw new TlbParameterNotFoundException(
                    "Commandline parameter not found: " + key);

        return param;
    }

    private void readCmdArgs(String[] args) {
        if (args.length < 2)
            this.showCmdHelp();

        for (int i = 0; i < args.length;) {
            String cmdName = args[i];
            String cmdValue = args[i+1];
            if (cmdName.startsWith("-") && !cmdValue.startsWith("-")) {
                this.put(cmdName.substring(1), cmdValue);
                i+=2;
            }else {
                this.showCmdHelp();
                break;

View on GitHub (pinned to d036ad9781)

Solutions

1. Add the missing parameter to the com2java command line (check the key name shown in the message)
2. Verify argument syntax expected by TlbCmdlineArgs (key=value pairs)
3. Wrap the generator invocation in a script that validates required args before running
4. If the param is genuinely optional in your flow, use getParam instead of getRequiredParam

Example fix

// before
java -jar com2java.jar -output C:\out mylib.tlb
// after
java -jar com2java.jar -tlb mylib.tlb -output C:\out -package com.mylib.jna

Map<String,String> args = parse(argsArray);
for (String required : List.of("tlb", "output")) {
    if (!args.containsKey(required)) throw new IllegalArgumentException("missing arg: " + required);
}

try { String tlb = cmdArgs.getRequiredParam("tlb"); } catch (TlbParameterNotFoundException e) { /* print usage with e.getMessage() */ }

When it happens

Trigger: Calling TlbCmdlineArgs.param/getRequiredParam (directly or via TlbImp) for a key such as 'tlb' or 'output' that was never passed on the command line, or passed with wrong spelling/missing '=' separator.

Common situations: Invoking com2java from an Ant/CI script with an incomplete argument list; upgrading JNA's contrib tool and a previously optional parameter becoming required; forgetting quoting so one of two arguments is lost.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• Output directory NOT sucessfully created to: <comRootDir>
• remove
• advise: Interface must define a value for either iid via the
• ComInterface must define a value for iid
• Class type <paramTypes[i].getName()> not mapped to primitive

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/6dd5eb263b965dcf. Report an issue: GitHub.