Commons Daemon, formerly known as JSVC, is a

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

software library In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and sub ...

belonging to the Apache Commons Project. Daemon provides a portable means of starting and stopping a

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 describ ...

(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.

References

{{reflist Java (programming language) libraries Commons Daemon