Launching Hello.java - My First Java Program

This section provides a tutorial example on how to launch a simple java program using the 'java' tool without any options.

To test the Java launcher, 'java', I wrote the following Java file, Hello.java:

class Hello {
   public static void main(String[] a) {
      System.out.println("Hello world!"); 	
   }
}

Here is what I did in a command window to compile Hello.java into Hello.class:

C:\herong>javac Hello.java

C:\herong>dir Hello.*
   416 Hello.class
   116 Hello.java

C:\herong>java Hello
Hello world!

As you can see, launching a simple Java application is easy - Run the 'java' command without any options followed by the class name.

Last update: 2018.

Table of Contents

 About This Book

 Java Tools Terminology

 Java Tools Included in JDK

 javac - The Java Program Compiler

 jar - The JAR File Tool

 jlink - The JRE Linker

 jmod - The JMOD File Tool

 jimage - The JIMAGE File Tool

java - The Java Program Launcher

 java - Program Launching Command and Options

Launching Hello.java - My First Java Program

 "java -classpath" - Specifying Class Path

 "java -jar" - Specifying Executable JAR File

 "java -X" - Specifying Non-Standard Options

 "java --list-modules" - Listing Modules in JDK

 "java --describe-module" - Printing Module Definition

 "java --module" - Launching Program from Module

 "java --module" - Launching Program from Module JAR

 javaw - Launching Java Programs without Console

 jdb - The Java Debugger

 jcmd - The JVM Diagnostic Tool

 jconsole - Java Monitoring and Management Console

 jstat - JVM Statistics Monitoring Tool

 JVM Troubleshooting Tools

 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

 native2ascii - Native-to-ASCII Encoding Converter

 Outdated Tutorials

 References

 Full Version in PDF/EPUB