How to handle a Findbugs “Non-transient non-serializable instance field in serializable class”?

Question

Consider the class below. If I run Findbugs against it it will give me an error (\"Non-transient non-serializable instance field in serializable class\") on line 5 but not o

Answer 1

You could use a capture helper to ensure that a passed in Set supports two interfaces:

private static class SerializableTestClass & Serializable> implements Serializable
{
    private static final long serialVersionUID = 1L;
    private final T serializableSet;

    private SerializableTestClass(T serializableSet)
    {
        this.serializableSet = serializableSet;
    }
}

public static class PublicApiTestClass
{
    public static  & Serializable> Serializable forSerializableSet(T set)
    {
        return new SerializableTestClass(set);
    }
}

In this way you can have a public API that enforces Serializable without checking/requiring specific implementation details.