To follow up on this a bit, since I spent a bit of time attempting to optimize this - the two big performance wins are:
1. Cache a byte[] and reuse it for every JAR entry (pass in a lambda to read() rather than get out a Map<String,byte[]>) 2. Maven's DefaultScanner will pass the indexer *every single file* in the repository it's indexing, while NetBeans is likely uninterested in .sha1 files and similar; filtering the list of files to things NetBeans is likely to be interested offers large benefits These two optimizations cut scanning time of my ~/.m2/repository dir (~2700 JAR files) from 42304ms to 30100ms, which is a 29% performance improvement with That said, I have some tests to get passing before this is patch-worthy, so we'll see if those results hold up. Of course, this only helps local indexing - whatever "Unpacking indexes" is doing with remote repositories won't be helped by this. Still, it seems like something that could be optimized quite a bit before giving up on it. If anyone's interested in poking at this: https://timboudreau.com/files/maven-indexer.diff -Tim
