java-native-access/jna · error · IllegalArgumentException

must be set from long/long[]

Error message

 must be set from long/long[]

What it means

For EvtVarTypeHexInt64, EvtVarTypeInt64 and EvtVarTypeUInt64, setValue requires a primitive long (getClass() == long.class) or a long[] array. Other types raise IllegalArgumentException '<TypeName> must be set from long/long[]'.

Source

Thrown at contrib/platform/src/com/sun/jna/platform/win32/Winevt.java:405

                            throw new IllegalArgumentException(type.name() + " must be set from int/int[]");
                        }
                        break;
                    case EvtVarTypeHexInt64:
                    case EvtVarTypeInt64:
                    case EvtVarTypeUInt64:
                        if (value.getClass().isArray() && value.getClass().getComponentType() == long.class) {
                            Type = type.ordinal() | EVT_VARIANT_TYPE_ARRAY;
                            Memory mem = new Memory(((long[]) value).length * 4);
                            mem.write(0, (long[]) value, 0, ((long[]) value).length);
                            holder = mem;
                            Count = 0;
                            field1.writeField("pointerValue", mem);
                        } else if (value.getClass() == long.class) {
                            Type = type.ordinal();
                            Count = 0;
                            field1.writeField("longValue", value);
                        } else {
                            throw new IllegalArgumentException(type.name() + " must be set from long/long[]");
                        }
                        break;
                    case EvtVarTypeSingle:
                        if (value.getClass().isArray() && value.getClass().getComponentType() == float.class) {
                            Type = type.ordinal() | EVT_VARIANT_TYPE_ARRAY;
                            Memory mem = new Memory(((float[]) value).length * 4);
                            mem.write(0, (float[]) value, 0, ((float[]) value).length);
                            holder = mem;
                            Count = 0;
                            field1.writeField("pointerValue", mem);
                        } else if (value.getClass() == float.class) {
                            Type = type.ordinal();
                            Count = 0;
                            field1.writeField("floatValue", value);
                        } else {
                            throw new IllegalArgumentException(type.name() + " must be set from float/float[]");
                        }
                        break;

View on GitHub (pinned to d036ad9781)

Solutions

1. Cast to long: (long) intValue — widening is safe for signed values
2. Convert List<Long>/Long[] to long[] with a loop or Arrays.stream(longBoxed).mapToLong(Long::longValue).toArray()
3. For BigInteger use bigInteger.longValueExact() to avoid silent truncation

Example fix

// before
variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeUInt64, integerList.toArray()); // Integer[]
// after
long[] longs = new long[integerList.size()];
for (int i = 0; i < longs.length; i++) longs[i] = integerList.get(i).longValue();
variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeUInt64, longs);

if (value instanceof Integer) value = (long) (Integer) value;
else if (value instanceof BigInteger) value = ((BigInteger) value).longValueExact();

boolean isLongVariant(Object v) {
    return v != null && (v.getClass() == long.class || v.getClass() == long[].class);
}

try {
    variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeUInt64, value);
} catch (IllegalArgumentException e) {
    variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeUInt64, ((Number) value).longValue());
}

When it happens

Trigger: setValue(EVT_VARIANT_TYPE.EvtVarTypeUInt64, intValue) — an int passed for a 64-bit field; or an Integer/Long boxed in a collection so getClass() is the wrapper class.

Common situations: Timestamps or file times kept as Integer; values from List<Long> converted with toArray() giving Long[]; BigIntegers from parsing hex strings.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• must be set from String/String[]
• must be set from BOOL/BOOL[]
• must be set from byte/byte[]
• must be set from short/short[]
• must be set from int/int[]

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/19bdce3eed95a495. Report an issue: GitHub.