java

launches Java applications

TLDR

Run class file

$ java [ClassName]

Run JAR file

$ java -jar [application.jar]

Run with classpath

$ java -cp [path/to/classes] [ClassName]

Set heap size

$ java -Xmx[512m] -jar [app.jar]

Run with system property

$ java -D[property=value] [ClassName]

Show version

$ java -version

Run single source file

$ java [Source.java]

SYNOPSIS

java [options] class [args...]java [options] -jar jarfile [args...]

java launches Java applications by loading and executing compiled bytecode in the Java Virtual Machine (JVM). It supports class files, JAR archives, and since Java 11, single source-file programs.The JVM handles memory management (garbage collection), threading, and platform abstraction. Memory is configured via -Xms (initial heap), -Xmx (max heap), and -Xss (stack size). System properties (-D) configure application behavior at runtime.

PARAMETERS

CLASS

Main class to execute.

-jar FILE

Execute JAR file.

-cp PATH

Class path for dependencies.

-Xmx SIZE

Maximum heap size.

-Xms SIZE

Initial heap size.

-D PROP=VAL

Set system property.

-Xss SIZE

Thread stack size.

-ea, --enableassertions

Enable assertions.

--enable-preview

Enable preview language features.

-verbose :class|:gc|:jni

Enable verbose output.

-version

Show version information.

--help

Display help information.

CAVEATS

Requires JRE/JDK. Version compatibility matters. Memory settings may need tuning.

HISTORY

Java was created by James Gosling at Sun Microsystems in 1995. It's now maintained by Oracle and the OpenJDK community.