Groovy in Action: Covers Groovy 2.4
Erik Pragt
Solr in Action
Trey Grainger & Timothy Potter
Information Doesn't Want to Be Free: Laws for the Internet Age
Cory Doctorow & Amanda Palmer & Neil Gaiman
Network Security Essentials: Applications and Standards
William Stallings
Mastering Bitcoin: Programming the Open Blockchain
Andreas M. Antonopoulos