Sure! Here's a detailed markdown article explaining the differences between java, javaw, and javaws.

The Java platform provides several command-line tools for different purposes, among which java, javaw, and javaws are commonly encountered. Each serves a unique role within the Java ecosystem, especially when dealing with the execution of Java applications. Below is a detailed explanation of these commands, complete with examples and technical details.

Java Command-Line Tools

java

The java command is one of the most fundamental tools of the Java platform. It is used to launch Java applications by executing their compiled bytecode. Essentially, the java command initiates the Java Virtual Machine (JVM) and allows it to run Java .class files or JAR files.

Features:

• Standard Output and Error: java provides both standard output and error output streams, meaning that any print statements or errors encountered can be displayed directly in the terminal or console.
• Environment: The command executes in a command-line environment, which makes it suitable for both desktop applications and server-side applications.
• Arguments: It supports passing command-line arguments to the Java program.

Example Usage:

To run a Java program, MyApp, with java, the command looks like:

java MyApp

If MyApp requires arguments:

java MyApp arg1 arg2

javaw

javaw is similar to java but is designed for Windows environments where you wish to suppress the command-line window entirely. It launches the application without an associated console window, which is useful when running graphical user interface (GUI) applications.

Features:

• No Console Window: This is the key difference; javaw does not open a command prompt window, which is useful for GUI applications where console output is unnecessary.
• Error Reporting: Any exceptions or errors must be handled within the application itself, as there won't be console output to display such messages.

Example Usage:

To run a GUI-based application, MyGuiApp, without a console window:

javaw MyGuiApp

javaws

javaws stands for Java Web Start. It is a deprecated technology as of Java 11, used to launch rich Internet applications and client desktop applications directly from a web browser or via a network. It provides an easy way to deploy Java applications over a network.

Features:

• Network Launching: Allows Java applications to be launched over a network, usually using JNLP (Java Network Launch Protocol) files.
• Version Management: Ensures that users run the correct version of an application by managing the application’s resource lifecycle automatically.
• Security: Provides a sandboxed environment with strict security features.

Example Usage:

To launch an application defined by a JNLP file:

javaws http://example.com/myapp.jnlp

Summary Table

Below is a summary of the key differences between java, javaw, and javaws:

Additional Details

Error Handling

• java and javaw: While java displays errors directly in the console, javaw requires log messages or error notifications embedded within the application itself.
• javaws: Applications can log errors to a defined file or handle them interactively with user dialogs, depending on the application design.

Lifecycle Management

• javaws: Automates version management and can ensure that users always have the latest version of an application. This requires a properly designed JNLP file and server-side setup to control resource versions and deployments.

Conclusion

Understanding the differences between these commands is crucial for developers working within the Java ecosystem. Selecting the appropriate tool depends on the application context—whether you're focusing on standard command-line execution, GUI application without console output, or network-driven application deployments. Despite the depreciation of javaws, familiarity with its fundamentals may be useful when maintaining or transitioning existing Java applications.

This article aims to explain the functionality of java, javaw, and javaws command-line utilities within the Java platform, facilitating better-informed decisions when deploying Java applications.