Parsing very large XML documents (and a bit more) in java

Question

(All of the following is to be written in Java)

I have to build an application that will take as input XML documents that are, potentially, very large. The document

Answer 1

You might be interested by XOM:

XOM is fairly unique in that it is a dual streaming/tree-based API. Individual nodes in the tree can be processed while the document is still being built. The enables XOM programs to operate almost as fast as the underlying parser can supply data. You don't need to wait for the document to be completely parsed before you can start working with it.

XOM is very memory efficient. If you read an entire document into memory, XOM uses as little memory as possible. More importantly, XOM allows you to filter documents as they're built so you don't have to build the parts of the tree you aren't interested in. For instance, you can skip building text nodes that only represent boundary white space, if such white space is not significant in your application. You can even process a document piece by piece and throw away each piece when you're done with it. XOM has been used to process documents that are gigabytes in size.