private void recalcHashes(DataNode item) throws IOException { if (item.dirty == null) { return; // not dirty, which means no children are dirty } // only directories have derived hashes if (item instanceof DirectoryNode) { DirectoryNode dirNode = (DirectoryNode) item; for (DataNode child : dirNode) { recalcHashes(child); } ByteArrayOutputStream bout = new ByteArrayOutputStream(); hashCalc.sort(dirNode.getChildren()); String newHash = hashCalc.calcHash(dirNode, bout); item.setHash(newHash); byte[] arrTriplets = bout.toByteArray(); blobStore.setBlob(newHash, arrTriplets); log.info( "recalcHashes: " + item.name + " children:" + dirNode.members.size() + " hash=" + newHash); } }