java-native-access/jna · error · IllegalArgumentException

must be set from BOOL/BOOL[]

Error message

 must be set from BOOL/BOOL[]

What it means

For EvtVarTypeBoolean, setValue only accepts a BOOL (single value, stored via intValue) or a BOOL[] (stored as an array in native memory). Any other object — Java Boolean, boolean[], int, etc. — triggers this IllegalArgumentException naming the variant type.

Source

Thrown at contrib/platform/src/com/sun/jna/platform/win32/Winevt.java:316

                            throw new IllegalArgumentException(type.name() + " must be set from String/String[]");
                        }
                        break;
                    case EvtVarTypeBoolean:
                        if (value.getClass().isArray() && value.getClass().getComponentType() == BOOL.class) {
                            Type = type.ordinal() | EVT_VARIANT_TYPE_ARRAY;
                            Memory mem = new Memory(((BOOL[]) value).length * 4);
                            for (int i = 0; i < ((BOOL[]) value).length; i++) {
                                mem.setInt(i * 4, ((BOOL[]) value)[i].intValue());
                            }
                            holder = mem;
                            Count = 0;
                            field1.writeField("pointerValue", mem);
                        } else if (value.getClass() == BOOL.class) {
                            Type = type.ordinal();
                            Count = 0;
                            field1.writeField("intValue", ((BOOL) value).intValue());
                        } else {
                            throw new IllegalArgumentException(type.name() + " must be set from BOOL/BOOL[]");
                        }
                        break;
                    case EvtVarTypeString:
                    case EvtVarTypeEvtXml:
                        if (value.getClass().isArray() && value.getClass().getComponentType() == String.class) {
                            Type = type.ordinal() | EVT_VARIANT_TYPE_ARRAY;
                            StringArray sa = new StringArray((String[]) value, true);
                            holder = sa;
                            Count = ((String[]) value).length;
                            field1.writeField("pointerValue", sa);
                        } else if (value.getClass() == String.class) {
                            Type = type.ordinal();
                            Memory mem = new Memory((((String) value).length() + 1) * 2);
                            mem.setWideString(0, (String) value);
                            holder = mem;
                            Count = 0;
                            field1.writeField("pointerValue", mem);
                        } else {

View on GitHub (pinned to d036ad9781)

Solutions

1. Wrap the value: new BOOL(true) for a single value
2. Convert arrays element-wise: BOOL[] arr = Arrays.stream(booleans).mapToObj(b -> new BOOL(b)).toArray(BOOL[]::new); or a loop for boolean[]
3. If the value is java.lang.Boolean, call bool.booleanValue() first and wrap in BOOL

Example fix

// before
variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeBoolean, true);
// after
variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeBoolean, new BOOL(true));

boolean ok = value instanceof BOOL
    || (value != null && value.getClass() == BOOL[].class);
if (!ok) throw new IllegalArgumentException("Boolean variant needs BOOL/BOOL[]");

boolean isBoolVariant(Object v) {
    return v instanceof BOOL || (v != null && v.getClass() == BOOL[].class);
}

try {
    variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeBoolean, value);
} catch (IllegalArgumentException e) {
    variant.setValue(EVT_VARIANT_TYPE.EvtVarTypeBoolean,
        new BOOL(((Boolean) value).booleanValue()));
}

When it happens

Trigger: setValue(EVT_VARIANT_TYPE.EvtVarTypeBoolean, Boolean.TRUE) or setValue(..., new boolean[]{true}) — the JNA wrapper demands its own com.sun.jna.platform.win32.BOOL wrapper type, not java.lang.Boolean or primitive boolean[].

Common situations: Passing Java's Boolean/boolean[] directly because the developer assumed auto-boxing support; constructing event values from JSON where booleans deserialize to java.lang.Boolean.

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 byte/byte[]
• must be set from short/short[]
• must be set from int/int[]
• must be set from long/long[]

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/838af68790add9c9. Report an issue: GitHub.