java. lang -- basic language functionality and fundamental types java. util -- collection data structure classes java.io -- file operations java. math -- multiprecision arithmetics java. nio -- the Non-blocking I / O framework for Java java.net -- networking operations, sockets, DNS lookups,... java. security -- key generation, encryption and decryption java. sql -- Java Database Connectivity (JDBC) to access databases java. awt -- basic hierarchy of packages for native GUI components java. text -- Provides classes and interfaces for handling text, dates, numbers, and messages in a manner independent of natural languages. java. rmi -- Provides the RMI package. java. time -- The main API for dates, times, instants, and durations. java. beans -- The java. beans package contains classes and interfaces related to JavaBeans components.
all standard classes of java are included within a package called
java. util