Commons Daemon

Last updated
Commons Daemon
Developer(s) Apache Software Foundation
Stable release
1.3.4 [1] / May 10, 2023;2 months ago (2023-05-10)
Written in Java, C
Operating system Cross-platform
Type Library
License Apache License 2.0
Website commons.apache.org/daemon

Commons Daemon, formerly known as JSVC, is a Java software library belonging to the Apache Commons Project.

Daemon provides a portable means of starting and stopping a Java Virtual Machine (JVM) that is running server-side applications. Such applications often have additional requirements compared to client-side applications. For example, the servlet container Tomcat 4 would need to serialize sessions and shutdown web applications before the JVM process terminates.

Daemon comprises 2 parts: a native library written in C that interfaces with the operating system, and the library that provides the Daemon API, written in Java.

There are two ways to use Commons Daemon: by implementing the daemon interface or by calling a class that provides the required methods for daemon. For example, Tomcat-4.1.x uses the daemon interface and Tomcat-5.0.x provides a class whose methods are called by JSVC directly.

Related Research Articles

<span class="mw-page-title-main">Java (programming language)</span> Object-oriented programming language

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities that are typically not available in traditional compiled languages. As of 2019, Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers.

<span class="mw-page-title-main">Java virtual machine</span> Java Virtual machine

A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.

Jakarta Enterprise Beans is one of several Java APIs for modular construction of enterprise software. EJB is a server-side software component that encapsulates business logic of an application. An EJB web container provides a runtime environment for web related software components, including computer security, Java servlet lifecycle management, transaction processing, and other web services. The EJB specification is a subset of the Java EE specification.

<span class="mw-page-title-main">Apache Tomcat</span> Java-based HTTP web server environment

Apache Tomcat is a free and open-source implementation of the Jakarta Servlet, Jakarta Expression Language, and WebSocket technologies. It provides a "pure Java" HTTP web server environment in which Java code can also run. Thus it is a Java web application server, although not a full JEE application server.

In software design, the Java Native Interface (JNI) is a foreign function interface programming framework that enables Java code running in a Java virtual machine (JVM) to call and be called by native applications and libraries written in other languages such as C, C++ and assembly.

<span class="mw-page-title-main">Adobe ColdFusion</span> Rapid Web app development platform

Adobe ColdFusion is a commercial rapid web-application development computing platform created by J. J. Allaire in 1995. ColdFusion was originally designed to make it easier to connect simple HTML pages to a database. By version 2 (1996) it had become a full platform that included an IDE in addition to a full scripting language.

<span class="mw-page-title-main">Apache Ant</span> Java software tool

Apache Ant is a software tool for automating software build processes which originated from the Apache Tomcat project in early 2000 as a replacement for the Make build tool of Unix. It is similar to Make, but is implemented using the Java language and requires the Java platform. Unlike Make, which uses the Makefile format, Ant uses XML to describe the code build process and its dependencies.

<span class="mw-page-title-main">Apache Groovy</span> Programming language

Apache Groovy is a Java-syntax-compatible object-oriented programming language for the Java platform. It is both a static and dynamic language with features similar to those of Python, Ruby, and Smalltalk. It can be used as both a programming language and a scripting language for the Java Platform, is compiled to Java virtual machine (JVM) bytecode, and interoperates seamlessly with other Java code and libraries. Groovy uses a curly-bracket syntax similar to Java's. Groovy supports closures, multiline strings, and expressions embedded in strings. Much of Groovy's power lies in its AST transformations, triggered through annotations.

<span class="mw-page-title-main">Apache Axis</span> Web service framework

Apache Axis is an open-source, XML based Web service framework. It consists of a Java and a C++ implementation of the SOAP server, and various utilities and APIs for generating and deploying Web service applications. Using Apache Axis, developers can create interoperable, distributed computing applications. Axis development takes place under the auspices of the Apache Software Foundation.

Apache Harmony is a retired open source, free Java implementation, developed by the Apache Software Foundation. It was announced in early May 2005 and on October 25, 2006, the board of directors voted to make Apache Harmony a top-level project. The Harmony project achieved 99% completeness for J2SE 5.0, and 97% for Java SE 6. The Android operating system has historically been a major user of Harmony, although since Android Nougat it increasingly relies on OpenJDK libraries.

Web server software allows computers to act as web servers. The first web servers supported only static files, such as HTML, but now they commonly allow embedding of server side applications.

<span class="mw-page-title-main">Scala (programming language)</span> General-purpose programming language

Scala is a strong statically typed high-level general-purpose programming language that supports both object-oriented programming and functional programming. Designed to be concise, many of Scala's design decisions are aimed to address criticisms of Java.

In software engineering, a WAR file is a file used to distribute a collection of JAR-files, JavaServer Pages, Java Servlets, Java classes, XML files, tag libraries, static web pages and other resources that together constitute a web application.

<span class="mw-page-title-main">Java (software platform)</span> Set of computer software and specifications

Java is a set of computer software and specifications developed by James Gosling at Sun Microsystems that provides a system for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages.

<span class="mw-page-title-main">Google Web Toolkit</span> Free Java library

Google Web Toolkit, or GWT Web Toolkit, is an open-source set of tools that allows web developers to create and maintain JavaScript front-end applications in Java. It is licensed under Apache License 2.0.

In software development, the programming language Java was historically considered slower than the fastest 3rd generation typed languages such as C and C++. The main reason being a different language design, where after compiling, Java programs run on a Java virtual machine (JVM) rather than directly on the computer's processor as native code, as do C and C++ programs. Performance was a matter of concern because much business software has been written in Java after the language quickly became popular in the late 1990s and early 2000s.

<span class="mw-page-title-main">Apache Pivot</span> Open-source platform for building applications in Java

Apache Pivot is an open-source platform for building rich web applications in Java or any JVM-compatible language. It is released under the Apache License version 2.0.

The Java Development Kit (JDK) is a distribution of Java Technology by Oracle Corporation. It implements the Java Language Specification (JLS) and the Java Virtual Machine Specification (JVMS) and provides the Standard Edition (SE) of the Java Application Programming Interface (API). It is derivative of the community driven OpenJDK which Oracle stewards. It provides software for working with Java applications. Examples of included software are the virtual machine, a compiler, performance monitoring tools, a debugger, and other utilities that Oracle considers useful for a Java programmer.

Kotlin is a cross-platform, statically typed, general-purpose high-level programming language with type inference. Kotlin is designed to interoperate fully with Java, and the JVM version of Kotlin's standard library depends on the Java Class Library, but type inference allows its syntax to be more concise. Kotlin mainly targets the JVM, but also compiles to JavaScript or native code via LLVM. Language development costs are borne by JetBrains, while the Kotlin Foundation protects the Kotlin trademark.

References

  1. "Daemon – Apache Commons Daemon Release Notes".