| Package | Enhancements | More Information | 
|---|
| java.lang 
  Provides classes that are fundamental to the design of the Java programming
  language such as String, Math, and basic runtime support for threads
  and processes.
   | J2SE 5.0,
 J2SDK 1.4, and
 J2SDK 1.3
 
 |  | 
| java.lang.annotation 
  Provides library support for the Java programming language annotation
  facility.
   | New in J2SE 5.0
 |  | 
| java.lang.instrument 
  Provides services that allow Java programming language agents to
  instrument programs running on the JVM.
   | Java SE 6 and
 J2SE 5.0
 |  | 
| java.lang.management 
  Provides the management interface for monitoring and management of
  the JVM as well as the operating system on which the JVM is running.
   | Java SE 6
 |  | 
| java.lang.ref  
  Provides reference-object classes, which support a limited degree of
  interaction with the garbage collector.
   | New in J2SDK 1.3 |  | 
| java.lang.reflect 
  Provides classes and interfaces for obtaining reflective information about
  classes and objects.
   | Java SE 6,
 J2SE 5.0, and
 J2SDK 1.4
 |  | 
| java.util 
  Provides the collections framework, formatted printing and scanning, array
  manipulation utilities, event model, date and time facilities,
  internationalization, and miscellaneous utility classes.
   | Java SE 6,
 J2SE 5.0, and
 J2SDK 1.3
 
 |  | 
| java.util.concurrent java.util.concurrent.atomic
 java.util.concurrent.locks
 
  Provides utility classes used in concurrent programming, including support
  for atomic updates of single variables and a locking framework which
  supplements language-level synchronization.
   | New in J2SE 5.0
 |  | 
| java.util.jar java.util.zip
 
  Provides classes for reading and writing the standard ZIP and GZIP file
  formats as well as the JAR (Java ARchive) file format, which is based on the
  standard ZIP file format with an optional manifest file.
   | Java SE 6 and
 J2SDK 1.3
 |  | 
| java.util.logging 
  Provides support to maintain and service software at customer sites.
   | J2SE 5.0 and
 J2SDK 1.4
 |  | 
| java.util.regex 
  Provides classes for matching character sequences against patterns specified
  by regular expressions.
   | New in J2SDK 1.4
 |  | 
| java.util.prefs 
  Provides classes to store and retrieve user and system preference and
  configuration data.
   | J2SDK 1.4
 |  | 
| java.util.spi 
  Service provider classes for the java.util package.
  
| New in Java SE 6
 |  |  |