JAR File Documentation

Overview

Feature Value
File Extension .jar
Full Form Java Archive File
MIME Type application/java-archive
File Format ZIP
Primary Usage Aggregating many files into one
Contains Java classes, metadata, resources
Compression Yes
Manifest File META-INF/MANIFEST.MF
Executable Yes, if contains a main class
Main Class Declaration Yes, in the manifest file
Can Contain Native Libraries Yes
Signature META-INF/*.SF, META-INF/*.RSA, META-INF/*.DSA
Popular Development Tools Java Development Kit (JDK), Eclipse, IntelliJ IDEA
Used By Java Frameworks, Applications, Applets
Security Can be signed to verify the author
Accessibility Can be extracted using ZIP tools
Standard Developed by Sun Microsystems (now Oracle)
Advantages Portability, security, compactness
Disadvantages Might require Java runtime for execution
Associated Programs Java Runtime Environment (JRE), Java Development Kit (JDK)
Encoding Binary