Bit Coin Core Client for Java (B3C4J)
B3C4J (in short for Bit Coin Core Client for Java) is a Java based client for use with Bitcoin Core (bitcoind). B3C4J is specifically created by a team of software professionals with solid background in building enterprise financial services applications and platforms.
Compared to other libraries, the differentiating features include broader support for RPC calls, BigDecimal, multi-thread safe, etc.
Bitcoin’s Blockchain Data Navigator (BitNavi)
BitNavi (in short for Bitcoin’s Blockchain Data Navigator) is an end-to-end solution for storing Bitcoin block data in real-time in RDBMS and navigating the same. BitNavi provides both web and REST API interface for browsing the entire blockchain. By storing in an RDBMS, it allows users to query the block data using SQL besides using REST API.
BitNavi keeps track of all the raw blockchain information like blocks, transactions, inputs/outputs, difficulty, fees, addresses, etc.