java-native-access/jna · error · RuntimeException

Unsupported type:

Error message

Unsupported type: 

What it means

registryGetValues enumerates each value, switches on the type reported by RegQueryValueEx, and decodes REG_SZ/REG_EXPAND_SZ, REG_DWORD, REG_QWORD, REG_BINARY and REG_MULTI_SZ into Java objects. A value whose type falls outside this set (e.g. REG_LINK, REG_RESOURCE_LIST, REG_FULL_RESOURCE_DESCRIPTOR, REG_RESOURCE_REQUIREMENTS_LIST) hits the default branch and throws this RuntimeException naming the numeric type. The library refuses to guess a decoding for unknown registry types.

Source

Thrown at contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java:2230

                            s = byteData.getString(offset);
                            offset += s.length();
                            offset += 1;
                        }

                        if (s.length() == 0) {
                            // A sequence of null-terminated strings,
                            // terminated by an empty string (\0).
                            // => The first empty string terminates the
                            break;
                        } else {
                            result.add(s);
                        }
                    }
                    keyValues.put(nameString, result.toArray(new String[0]));
                    break;
                }
                default:
                    throw new RuntimeException("Unsupported type: "
                        + lpType.getValue());
            }
        }
        return keyValues;
    }

    /**
     * Get a table of registry values.
     *
     * @param root
     *            Registry root.
     * @param keyPath
     *            Regitry key path.
     * @return Table of values.
     */
    public static TreeMap<String, Object> registryGetValues(HKEY root,
            String keyPath) {
        return registryGetValues(root, keyPath, 0);

View on GitHub (pinned to d036ad9781)

Solutions

1. Catch RuntimeException around registryGetValues per key and skip/log keys containing unsupported types.
2. Read individual values with registryGetValue and only the names you expect, avoiding unknown types.
3. Use Advapi32.registryQueryInfoKey yourself to inspect types and handle unsupported ones explicitly before decoding.
4. Update JNA - newer versions handle more registry types during enumeration.

Example fix

// before
TreeMap<String, Object> vals = Advapi32Util.registryGetValues(root, key); // throws on REG_RESOURCE_LIST

// after
TreeMap<String, Object> vals;
try {
    vals = Advapi32Util.registryGetValues(root, key);
} catch (RuntimeException e) {
    LOG.debug("Key {} has values with unsupported types, skipping", key);
    vals = new TreeMap<>();
}

// pre-check each value's type with RegQueryValueEx and skip unsupported ones:
Memory lpData = new Memory(4); IntByReference lpcb = new IntByReference(0);
IntByReference lpType = new IntByReference();
Advapi32.INSTANCE.RegQueryValueEx(hKey, valueName, 0, lpType, (Pointer) null, lpcb);
boolean supported = lpType.getValue() == WinNT.REG_SZ || lpType.getValue() == WinNT.REG_EXPAND_SZ
    || lpType.getValue() == WinNT.REG_MULTI_SZ || lpType.getValue() == WinNT.REG_DWORD
    || lpType.getValue() == WinNT.REG_QWORD || lpType.getValue() == WinNT.REG_BINARY;

try { return Advapi32Util.registryGetValues(root, key, 0); }
catch (RuntimeException e) { log.debug("Skipping key {} with unsupported value types", key); return Collections.emptyMap(); }

When it happens

Trigger: Calling Advapi32Util.registryGetValues(key) or registryGetValues(root, key, samDesiredExtra) on a key that contains a non-empty value of a type not in the supported set (REG_LINK, REG_RESOURCE_LIST, REG_FULL_RESOURCE_DESCRIPTOR, REG_RESOURCE_REQUIREMENTS_LIST, or vendor-defined types).

Common situations: Bulk-enumerating HKLM\SYSTEM\CurrentControlSet\Services or hardware Enum keys that commonly store resource-descriptor values; reading keys written by drivers or OEM tools using private types; security-scanning scripts walking whole hives.

Related errors

• Unsupported empty type:
• Unexpected registry type + lpType.getValue() + , expected RE
• Unexpected registry type {}, expected REG_SZ
• Unexpected registry type {}, expected REG_BINARY
• Unexpected registry type {}, expected REG_DWORD

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/96d824d15f1e62d0. Report an issue: GitHub.