Managing JAR Files with WinZIP

Java Tools Tutorials - Herong's Tutorial Examples

∟jar - The JAR File Tool

∟Managing JAR Files with WinZIP

This section provides a tutorial example on how to manage a JAR file as a ZIP file with the ZIP tool, WinZIP.

The JAR specification says that "JAR file is a file format based on the popular ZIP file format". So are JAR files really ZIP files? I did some tests to find out.

Test 1. Create a JAR file, test.jar, with "jar" command. Rename test.jar to test.zip. Unzip test.zip with WinZIP. You should have no problem to extract all files out of test.zip with WinZIP.

Test 2. Create a ZIP file, tutu.zip, with WinZIP. Rename tutu.zip to tutu.jar. Extract files from tutu.jar with "jar". You should have no problem to extract all files out of tutu.jar with "jar" command.

Test 3. Create a password protected ZIP file, secure.zip, with WinZIP. Rename secure.zip to secure.jar. Extract files from secure.jar with "jar". You should get a run time exception like this:

herong> jar --list --file secure.jar
java.util.zip.ZipException: invalid CEN header (encrypted entry)
   at java.base/java.util.zip.ZipFile$Source.zerror(ZipFile.java:1527)
   at java.base/java.util.zip.ZipFile$Source.initCEN(ZipFile.java:1493)
   ...
   at jdk.jartool/sun.tools.jar.Main.list(Main.java:1488)
   at jdk.jartool/sun.tools.jar.Main.run(Main.java:373)
   at jdk.jartool/sun.tools.jar.Main.main(Main.java:1669)

So JAR files and ZIP files are fully compatible, as long as no encryptions are used on ZIP files.

I guess I don't need WinZIP anymore. I can use "jar" command to manage ZIP files.

Or I don't need "jar" command. I can use WinZIP to manage JAR files!

Table of Contents

About This Book

Java Tools Terminology

Java Tools Included in JDK

javac - The Java Program Compiler

java - The Java Program Launcher

►jar - The JAR File Tool

JAR - Java Archive File Format

jar - JAR File Tool Command and Options

"jar --create" - Creating New JAR File

"jar --list" - Listing Files in JAR File

"jar --extract" - Extracting Files from JAR File

►Managing JAR Files with WinZIP

META-INF/MANIFEST.MF - JAR Manifest File

Adding META-INF/MANIFEST.MF to JAR Files

"jar -C" - Changing Input Directory

Using JAR Files in Java Class Paths

"jar --update" - Updating Class Files in JAR

"jar --main-class" - Making JAR File Executable

Creating Module JAR File

"jar --module-version" - Updating Module Version in JAR

jlink - The JRE Linker

jmod - The JMOD File Tool

jimage - The JIMAGE File Tool

jpackage - Binary Package Builder

javadoc - The Java Document Generator

jdeps - The Java Class Dependency Analyzer

jdeprscan - The Java Deprecated API Scanner

jdb - The Java Debugger

jcmd - The JVM Diagnostic Tool

jconsole - Java Monitoring and Management Console

jstat - JVM Statistics Monitoring Tool

JVM Troubleshooting Tools

jhsdb - The Java HotSpot Debugger

jvisualvm (Java VisualVM) - JVM Visual Tool

jmc - Java Mission Control

javap - The Java Class File Disassembler

keytool - Public Key Certificate Tool

jarsigner - JAR File Signer

jshell - Java Language Shell

jrunscript - Script Code Shell

Miscellaneous Tools

native2ascii - Native-to-ASCII Encoding Converter

JAB (Java Access Bridge) for Windows

Archived Tutorials

Full Version in PDF/EPUB