java.lang -
Provides classes that are fundamental to the design of the Java
programming language.
java.lang.annotation
- Provides library support for the Java programming language
annotation facility.
java.lang.instrument
- Provides services that allow Java programming language agents to
instrument programs running on the JVM.
java.lang.management
- Provides the management interface for monitoring and management
of the Java virtual machine as well as the operating system on
which the Java virtual machine is running.
java.lang.ref
- Provides reference-object classes, which support a limited degree
of interaction with the garbage collector.
java.lang.reflect
- Provides classes and interfaces for obtaining reflective
information about classes and objects.
java.util -
Contains the collectsions framework, legacy collection classes,
event model, date and time facilities, internationalization, and
miscellaneous utility classes (a string tokenizer, a random-number
generator, and a bit array).
java.util.concurrent
- Utility classes commonly useful in concurrent programming.
java.util.concurrent.atomic
- A small toolkit of classes that support lock-free thread-safe
programming on single variables.
java.util.concurrent.locks
- Interfaces and classes providing a framework for locking and
waiting for conditions that is distinct from built-in
synchronization and monitors.
java.util.jar
- Provides classes for reading and writing the JAR (Java ARchive)
file format, which is based on the standard ZIP file format with an
optional manifest file.
java.util.logging
- Provides the classes and interfaces of the Java 2 platform's core
logging facilities.
java.util.regex
- Classes for matching character sequences against patterns
specified by regular expressions.
java.util.prefs
- This package allows applications to store and retrieve user and
system preference and configuration data.
java.util.spi
- Service provider classes for the classes in the java.util
package.
java.util.zip
- Provides classes for reading and writing the standard ZIP and
GZIP file formats.