554 Part II: The Java Library
The java.util Subpackages
Java defines the following subpackages tojava.util:- java.util.concurrent
- java.util.concurrent.atomic
- java.util.concurrent.locks
- java.util.jar
- java.util.logging
- java.util.prefs
- java.util.regex
- java.util.spi
- java.util.zip
Each is briefly examined here.java.util.concurrent, java.util.concurrent.atomic, and java.util.concurrent.locks
Thejava.util.concurrentpackage along with its two subpackages,java.util.concurrent.atomic
andjava.util.concurrent.locks, support concurrent programming. These packages provide
a high-performance alternative to using Java’s built-in synchronization features when
thread-safe operation is required. These packages are examined in detail in Chapter 26.java.util.jar
Thejava.util.jarpackage provides the ability to read and write Java Archive (JAR) files.java.util.logging
Thejava.util.loggingpackage provides support for program activity logs, which can be
used to record program actions, and to help find and debug problems.java.util.prefs
Thejava.util.prefspackage provides support for user preferences. It is typically used to
support program configuration.java.util.regex
Thejava.util.regexpackage provides support for regular expression handling. It is described
in detail in Chapter 27.java.util.spi
Thejava.util.spipackage provides support for service providers. (Added by Java SE 6.)java.util.zip
Thejava.util.zippackage provides the ability to read and write files in the popular ZIP
and GZIP formats. Both ZIP and GZIP input and output streams are available.