How to build a bitcoinj checkpoint file How can I build a bitcoinj checkpoint file
like the Bitcoin-wallet checkpoints?
From this discussion: How to create a checkpoint file

Run mvn exec:java -Dexec.mainClass=com.google.bitcoin.tools.BuildCheckpoints in the tools/ directory from the bitcoinj repository.

BuildCheckpoints expects you to have a fully synced local Bitcoin-Qt/bitcoind instance running.