How to correctly create a file and write XML content? Is there any relevant use case?

[xuexixuexijpg]

[xuexixuexijpg]

Why can't I pass null to namespace or prefix so that namespaceHolder.nextAutoPrefix() is not used to automatically set appliedPrefix? It seems a bit troublesome now. Is there any API that can directly disable namespaceHolder from automatically getting nextAutoPrefix?

[pdvrieze]

The thing is that every tag/attribute name lives in a namespace. The prefix is merely the short way of referring to a specific namespace. The "" namespace is the default (or null) namespace that matches the empty/missing prefix "". It is possible to change the default prefix for tag names, but this does not apply to attributes. Attributes without prefix are always in the default namespace. If attributes are not intended to be used beyond the tag that defines them (they are not extensions of some sort) the recommendation/common practice is to use default namespace attributes.

What this code does (is intended to do - it doesn't look fully correct on reflection) is to:

• Treat a null namespace the same as the empty namespace
• If the namespace is null/empty, use an empty prefix
• If there is already a prefix declared for the namespace (for example by a namespace declaration attribute on the same element) use that
• If the provided prefix is null, pick an automatic prefix (as one is needed)

Looking at the code this code is probably incorrect (although you are actually looking at the fallback path as you are expected to use namepace attributes to declare it before using it.

But your example code should work by default (as you appear to want to not really use namespaces).