java.util.jar (Java SE 21 & JDK 21)
Description: declaration: module: java.base, package: java.util.jar
Keywords: java.util.jar package

Module java.base

# Package java.util.jar

package 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. The manifest stores meta-information about the JAR file contents and is also used for signing JAR files.

## Package Specification

The `java.util.jar` package is based on the following specifications:

- Info-ZIP file format - The JAR format is based on the Info-ZIP file format. See java.util.zip package description.

  In JAR files, all file names must be encoded in the UTF-8 encoding.

- Manifest and Signature Specification - The manifest format specification.

Since:
  1.2
External Specifications
  - JAR File Specification

- Related Packages
  Package
  Description
  java.util
  Contains the collections framework, some internationalization support classes, a service loader, properties, random number generation, string parsing and scanning classes, base64 encoding and decoding, a bit array, and several miscellaneous utility classes.
- Class
  Description
  Attributes
  The Attributes class maps Manifest attribute names to associated string values.
  Attributes.Name
  The Attributes.Name class represents an attribute name stored in this Map.
  JarEntry
  This class is used to represent a JAR file entry.
  JarException
  Signals that an error of some sort has occurred while reading from or writing to a JAR file.
  JarFile
  The `JarFile` class is used to read the contents of a jar file from any file that can be opened with `java.io.RandomAccessFile`.
  JarInputStream
  The `JarInputStream` class, which extends `ZipInputStream`, is used to read the contents of a JAR file from an input stream.
  JarOutputStream
  The `JarOutputStream` class is used to write the contents of a JAR file to any output stream.
  Manifest
  The Manifest class is used to maintain Manifest entry names and their associated Attributes.