Multi-version compatible JAR function allows us to choose to use the version of the class we want when running the library program in a specific version of the Java environment . We can specify the compiled version through the --release parameter.
One specific change is that there is a new attribute in the MANIFEST.MF file in the META-INF directory, as shown below
<strong>Multi-Release: true</strong>## There is a new version directory under the #"
META-INF" directory. If we want to support Java 9 version, there is a 9 directory under the versions directory.
<strong>multirelease.jar ├── META-INF │ └── versions │ └── 9 │ └── multirelease │ └── Helper.class ├── multirelease ├── Helper.class └── Main.class</strong>In the following example, we can use a
Multi-version compatible JAR function from "Test.java"The file generates two versions of jar packages. One version is jdk 7 and the other version is jdk 9, and then we execute it in different environments.
Step one: Create a folder in the C:/test/java7/com/tutorialspoint directory and create a "# in the folder ##Test.java" file, as shown below: <strong>package com.tutorialspoint;
public class Test {
public static void main(String args[]) {
System.out.println("Inside Java 7");
}
}</strong>
Create the folder C:/test/java9/com/tutorialspoint, and create a "Test.java" file in the folder as follows: <strong>package com.tutorialspoint;
public class Test {
public static void main(String args[]) {
System.out.println("Inside Java 9");
}
}</strong>
We can follow the following Method to compile code:
<strong>C:\test> javac --release 9 java9/com/tutorialspoint/Test.java C:\test> javac --release 7 java7/com/tutorialspoint/Test.java</strong>##We can create a
multi-version compatible jar package in the following way
<strong>C:\JAVA> jar -c -f test.jar -C java7 . --release 9 -C java9 Warning: entry META-INF/versions/9/com/tutorialspoint/Test.java, multiple resources with same name</strong>Use JDK 7 to execute:
<strong>C:\JAVA> java -cp test.jar com.tutorialspoint.Test Inside Java 7</strong>
##Use JDK 9 to execute:
<strong>C:\JAVA> java -cp test.jar com.tutorialspoint.Test Inside Java 9</strong>
The above is the detailed content of What is the use of multi-version compatible jars in Java 9?. For more information, please follow other related articles on the PHP Chinese website!

JVM handles operating system API differences through JavaNativeInterface (JNI) and Java standard library: 1. JNI allows Java code to call local code and directly interact with the operating system API. 2. The Java standard library provides a unified API, which is internally mapped to different operating system APIs to ensure that the code runs across platforms.

modularitydoesnotdirectlyaffectJava'splatformindependence.Java'splatformindependenceismaintainedbytheJVM,butmodularityinfluencesapplicationstructureandmanagement,indirectlyimpactingplatformindependence.1)Deploymentanddistributionbecomemoreefficientwi

BytecodeinJavaistheintermediaterepresentationthatenablesplatformindependence.1)Javacodeiscompiledintobytecodestoredin.classfiles.2)TheJVMinterpretsorcompilesthisbytecodeintomachinecodeatruntime,allowingthesamebytecodetorunonanydevicewithaJVM,thusfulf

JavaachievesplatformindependencethroughtheJavaVirtualMachine(JVM),whichexecutesbytecodeonanydevicewithaJVM.1)Javacodeiscompiledintobytecode.2)TheJVMinterpretsandexecutesthisbytecodeintomachine-specificinstructions,allowingthesamecodetorunondifferentp

Platform independence in JavaGUI development faces challenges, but can be dealt with by using Swing, JavaFX, unifying appearance, performance optimization, third-party libraries and cross-platform testing. JavaGUI development relies on AWT and Swing, which aims to provide cross-platform consistency, but the actual effect varies from operating system to operating system. Solutions include: 1) using Swing and JavaFX as GUI toolkits; 2) Unify the appearance through UIManager.setLookAndFeel(); 3) Optimize performance to suit different platforms; 4) using third-party libraries such as ApachePivot or SWT; 5) conduct cross-platform testing to ensure consistency.

Javadevelopmentisnotentirelyplatform-independentduetoseveralfactors.1)JVMvariationsaffectperformanceandbehavioracrossdifferentOS.2)NativelibrariesviaJNIintroduceplatform-specificissues.3)Filepathsandsystempropertiesdifferbetweenplatforms.4)GUIapplica

Java code will have performance differences when running on different platforms. 1) The implementation and optimization strategies of JVM are different, such as OracleJDK and OpenJDK. 2) The characteristics of the operating system, such as memory management and thread scheduling, will also affect performance. 3) Performance can be improved by selecting the appropriate JVM, adjusting JVM parameters and code optimization.

Java'splatformindependencehaslimitationsincludingperformanceoverhead,versioncompatibilityissues,challengeswithnativelibraryintegration,platform-specificfeatures,andJVMinstallation/maintenance.Thesefactorscomplicatethe"writeonce,runanywhere"


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
