LSPosed/LSPosed · error · NoSuchFieldError

Field of type ${type.getName()} in class ${clazz.getName()}

Error message

Field of type ${type.getName()} in class ${clazz.getName()}

What it means

XposedHelpers.findFirstFieldByExactType(Class, Class) walks the class hierarchy (getDeclaredFields on each level up to Object) looking for the first field whose declared type exactly matches (== identity, not assignability) the given type. If none matches it throws NoSuchFieldError with the type and class names. Note it is an Error, not an exception — a bug carried over from the original Xposed API for fail-fast module development.

Source

Thrown at core/src/main/java/de/robv/android/xposed/XposedHelpers.java:303

     * Might be useful for Proguard'ed classes to identify fields with unique types.
     *
     * @param clazz The class which either declares or inherits the field.
     * @param type  The type of the field.
     * @return A reference to the first field of the given type.
     * @throws NoSuchFieldError In case no matching field was not found.
     */
    public static Field findFirstFieldByExactType(Class<?> clazz, Class<?> type) {
        Class<?> clz = clazz;
        do {
            for (Field field : clz.getDeclaredFields()) {
                if (field.getType() == type) {
                    field.setAccessible(true);
                    return field;
                }
            }
        } while ((clz = clz.getSuperclass()) != null);

        throw new NoSuchFieldError("Field of type " + type.getName() + " in class " + clazz.getName());
    }

    /**
     * Look up a method and hook it. See {@link #findAndHookMethod(String, ClassLoader, String, Object...)}
     * for details.
     */
    public static XC_MethodHook.Unhook findAndHookMethod(Class<?> clazz, String methodName, Object... parameterTypesAndCallback) {
        if (parameterTypesAndCallback.length == 0 || !(parameterTypesAndCallback[parameterTypesAndCallback.length - 1] instanceof XC_MethodHook))
            throw new IllegalArgumentException("no callback defined");

        XC_MethodHook callback = (XC_MethodHook) parameterTypesAndCallback[parameterTypesAndCallback.length - 1];
        Method m = findMethodExact(clazz, methodName, getParameterClasses(clazz.getClassLoader(), parameterTypesAndCallback));

        return XposedBridge.hookMethod(m, callback);
    }

    /**
     * Look up a method and hook it. The last argument must be the callback for the hook.

View on GitHub (pinned to df74d83eb0)

Solutions

1. Verify the field exists with the exact declared type: dump clazz.getDeclaredFields() across the hierarchy and check field.getType() == wantedType.
2. If the declared type changed, search by that exact type, or switch to XposedHelpers.findField(clazz, name) if the name is stable.
3. Wrap the call in try/catch (NoSuchFieldError | Throwable) to degrade gracefully per Android version / OEM.
4. For subtype tolerance write a small loop using isAssignableFrom instead of this exact-match helper.

Example fix

// before
Field f = XposedHelpers.findFirstFieldByExactType(Activity.class, WindowManager.class); // NoSuchFieldError

// after
Field f = null;
try {
    f = XposedHelpers.findFirstFieldByExactType(Activity.class, WindowManager.class);
} catch (NoSuchFieldError e) {
    // version-specific layout: fall back to named lookup or skip feature
    f = XposedHelpers.findField(Activity.class, "mWindowManager");
}

static Field findFirstFieldByExactTypeSafe(Class<?> clazz, Class<?> type) {
    for (Class<?> c = clazz; c != null; c = c.getSuperclass())
        for (Field f : c.getDeclaredFields())
            if (f.getType() == type) return f;
    return null;
}

try {
    f = XposedHelpers.findFirstFieldByExactType(clazz, type);
} catch (NoSuchFieldError e) { // API throws Error, not Exception
    // version/OEM mismatch: skip feature or use named lookup
}

When it happens

Trigger: findFirstFieldByExactType(clazz, SomeType.class) where no field in clazz or any superclass is declared exactly as SomeType (a subclass field, a generic Object field, or an inherited field with a different declared type all fail).

Common situations: Android OEM updates change a framework field's declared type (e.g. a field refactored from a concrete type to an interface or vice versa); the field exists on a sibling class instead of a superclass; passing a subtype of the actual declared type (assignability is not considered); obfuscation/renaming in target apps.

Related errors

• No parameter of type {} found in {}
• Cannot hook Method.invoke
• More than one parameter of type {} found in {}
• Only methods and constructors can be deoptimized: ${deoptimi
• Cannot deoptimize abstract methods: ${deoptimizedMethod}

AI-assisted analysis of LSPosed/LSPosed@df74d83eb0 (2026-08-14). Data as JSON: /api/errors/eb2da017b82903ff. Report an issue: GitHub.