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Apache Tomcat

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Apache Tomcat
Original author(s)James Duncan Davidson
Developer(s)The Apache Software Foundation
Initial release1999;25 years ago(1999)
Stable release
10.1.26[1]Edit this on Wikidata / 12 July 2024
RepositoryTomcat Repository
Written inJava
TypeServlet container
HTTPweb server
LicenseApache-2.0
Websitetomcat.apache.orgEdit this on Wikidata

Apache Tomcat(called "Tomcat" for short) is afree and open-sourceimplementation of theJakarta Servlet,Jakarta Expression Language,andWebSockettechnologies.[2]It provides a "pure Java"HTTPweb serverenvironment in whichJavacode can also run. Thus it is a Java web application server, although not a full JEE application server.

Tomcat is developed and maintained by an open community of developers under the auspices of theApache Software Foundation,released under theApache License2.0 license.

Components

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Tomcat 4.x was released with Catalina (a servlet container), Coyote (an HTTP connector) and Jasper (aJSP engine).

Catalina

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Catalina is Tomcat'sservlet container.Catalina implementsSun Microsystems' specifications forservletand JavaServer Pages (JSP). In Tomcat, a Realm element represents a "database" of usernames, passwords, and roles (similar toUnixgroups) assigned to those users. Different implementations of Realm allow Catalina to be integrated into environments where such authentication information is already being created and maintained, and then use that information to implement Container Managed Security as described in the Servlet Specification.[3]

Coyote

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Coyote is a Connector component for Tomcat that supports the HTTP 1.1 and 2 protocol as a web server. This allows Catalina, nominally a Java Servlet or JSP container, to also act as a plain web server that serves local files as HTTP documents.[4]Coyote listens for incoming connections to the server on a specificTCPport and forwards the request to the Tomcat Engine to process the request and send back a response to the requesting client. Another Coyote Connector, Coyote JK, listens similarly but instead forwards its requests to another web server, such as Apache, using theJK Protocol.[5]This usually offers better performance.[citation needed]

Jasper

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Jasper is Tomcat's JSP Engine. JasperparsesJSPfiles to compile them into Java code as servlets (that can be handled by Catalina). At runtime, Jasper detects changes to JSP files and recompiles them.

As of version 5, Tomcat uses Jasper 2, which is an implementation of the Sun Microsystems' JSP 2.0 specification. From Jasper to Jasper 2, important features were added:

  • JSP Tag library pooling – Each tag markup in JSP file is handled by a tag handler class. Tag handler class objects can be pooled and reused in the whole JSP servlet.
  • Background JSP compilation – While recompiling modified JSP Java code, the older version is still available for server requests. The older JSP servlet is deleted once the new JSP servlet has finished being recompiled.
  • Recompile JSP when included page changes – pages can be inserted and included into a JSP at runtime. The JSP will not only be recompiled with JSP file changes but also with included page changes.
  • JDT Java compiler – Jasper 2 can use the Eclipse JDT (Java Development Tools) Java compiler instead ofAntandjavac.

Three new components were added with the release of Tomcat 7:

Cluster

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This component has been added to manage large applications. It is used forload balancingthat can be achieved through many techniques. Clustering support currently requires the JDK version 1.5 or higher.

High availability

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A high-availability feature has been added to facilitate the scheduling of system upgrades (e.g. new releases, change requests) without affecting the live environment. This is done by dispatching live traffic requests to a temporary server on a different port while the main server is upgraded on the main port. It is very useful in handling user requests on high-traffic web applications.[6]

Features

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Tomcat 9.x implements the Servlet 4.0 and JSP 2.3 Specifications.[7]

Tomcat 10.0.x implements the Servlet 5.0 and JSP 3.0 Specifications.[7]

Tomcat 10.1.x implements the Servlet 6.0 and JSP 3.1 Specifications.[7]

History

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Tomcat started off as a servletreference implementationbyJames Duncan Davidson,a software architect at Sun Microsystems. He later helped make the projectopen-sourceand played a key role in its donation by Sun Microsystems to the Apache Software Foundation.[8]TheApache Antsoftware build automation tool was developed as a side-effect of the creation of Tomcat as an open source project.

Davidson had initially hoped that the project would become open-sourced and, since many open-source projects hadO'Reillybooks associated with them featuring an animal on the cover, he wanted to name the project after an animal. He came up withTomcatsince he reasoned the animal represented something that could fend for itself. Although the tomcat was already in use for another O'Reilly title,[9]his wish to see an animal cover eventually came true when O'Reilly published their Tomcat book with asnow leopardon the cover in 2003.[10]

Releases

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Series[11] Declared stable Description Latest release Latest release date End of life[12]
Old version, no longer maintained:2.0 1998 Tomcat started off in November 1998[13]as a servletreference implementationbyJames Duncan Davidson,a software architect at Sun Microsystems. ? ? ?
Old version, no longer maintained:3.0 1999 Initial release. Merger of donated Sun Java Web Server code and ASF and Implements Servlet 2.2, and JSP 1.1 specifications. 3.3.2 2004-03-09 ?
Old version, no longer maintained:4.1 2002-09-06[14] First Apache Tomcat release to support the Servlet 2.3 and JSP 1.2[15]specifications. 4.1.40 2009-06-25 ?
Old version, no longer maintained:5.0 2003-12-03 Supports the Servlet 2.4, JSP 2.0, andEL 1.1[15]specifications. 5.0.30 2004-08-30 ?
Old version, no longer maintained:5.5[16] 2004-11-10[17] Designed for J2SE 5.0. Inclusion of Eclipse JDT allows Tomcat to run without a full Java Development Kit being installed. 5.5.36 2012-10-10 2012-09-30[18]
Old version, no longer maintained:6.0 2007-02-28[19] Supports the Servlet 2.5, JSP 2.1,[15]and EL 2.1 specifications. 6.0.53 2017-04-07 2016-12-31[20]
Old version, no longer maintained:7.0 2011-01-14[21] Supports the Servlet 3.0, JSP 2.2, EL 2.2, and WebSocket[15]specifications. 7.0.109 2021-04-26[22] 2021-03-31[23]
Old version, no longer maintained:8.0 2014-06-25[24] Supports the Servlet 3.1, JSP 2.3, and EL 3.0[15]specifications. 8.0.53 2018-07-05 2018-06-30[25]
Old version, no longer maintained:8.5 2016-06-13 Adds support forHTTP/2,OpenSSL for JSSE, TLS virtual hosting and JASPIC 1.1. Created from Tomcat 9, following delays to Java EE 8. 8.5.100 2024-03-25[26] 2024-03-31[27]
Older version, yet still maintained:9.0 2018-01-18 Supports the Servlet 4.0[15]specifications. 9.0.90 2024-06-19[28] TBA
Old version, no longer maintained:10.0 2021-02-02 Supports the Servlet 5.0, JSP 3.0, EL 4.0, WebSocket 2.0 and Authentication 2.0[15]specifications. 10.0.27 2022-10-10[29] 2022-10-31[30]
Current stable version:10.1 2022-09-26 Supports theJakartaServlet 6.0, JSP 3.1, EL 5.0, WebSocket 2.1, and JASPIC 3.0[15]specifications. 10.1.20 2024-03-25[31] TBA
Latest preview version of a future release:11.0 ( Alpha ) Supports theJakartaServlet 6.1, JSP 4.0, and as-yet-to-be-determined versions of EL, WebSocket, and JASPIC[15]specifications. 11.0.0-M18 2024-03-14[32] TBA
Legend:
Old version
Older version, still maintained
Latest version
Latest preview version
Future release


Apache TomEE

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Apache TomEE(pronounced "Tommy" ) is theEnterprise Editionof Apache Tomcat (Tomcat + Java/Jakarta EE = TomEE) that combines several Java enterprise projects includingApache OpenEJB,Apache OpenWebBeans,Apache OpenJPA,Apache MyFacesand others.[33]In October 2011, the project obtained certification byOracle Corporationas a compatible implementation of the Java EE 6 Web Profile.[34][35]

See also

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Related software that is now obsolete or defunct:

References

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  1. ^"Tomcat 10.1.26 (schultz)".12 July 2024.Retrieved13 July2024.
  2. ^"How to install Apache Tomcat on Ubuntu Server 16.04".21 March 2017.Retrieved2019-10-04.
  3. ^"Apache Tomcat Configuration Reference - The Realm Component".Tomcat.apache.org.Retrieved2013-11-01.
  4. ^The Coyote HTTP/1.1 Connector,Apache
  5. ^"Server Configuration Reference - The Coyote JK Connector".tomcat.apache.org.Retrieved24 August2018.
  6. ^King, Graham (December 20, 2004)."High availability Tomcat".JavaWorld.Retrieved2020-07-21.
  7. ^abc"Apache Tomcat Versions".Retrieved2022-08-26.
  8. ^Davidson, James Duncan(November 14, 2014)."What was the history of Tomcat inside Sun before it was open-sourced?".Quora.Retrieved2018-07-25.
  9. ^Sinan Si Alhir (1998),UML in a Nutshell,O'Reilly Books, pp.296,ISBN978-1-56592-448-2
  10. ^Brittain, Jason; Darwin, Ian F. (28 November 2007),Tomcat: The Definitive Guide(1st ed.),O'Reilly Media,p.320,ISBN978-0596003180,retrieved2018-03-01
  11. ^Apache Tomcat Versions
  12. ^"Tomcat Versions - Apache Tomcat".cwiki.apache.org.The Apache Software Foundation.Retrieved2020-07-20.
  13. ^"The Origin Story of Tomcat".TechNotif. 24 April 2015.Archivedfrom the original on 30 June 2018.Retrieved23 July2017.
  14. ^"[ANNOUNCEMENT] Tomcat 4.1.10 Stable".Retrieved21 September2015.
  15. ^abcdefghiSaegesser, Marc A."Apache Tomcat - Which Version Do I Want?".tomcat.apache.org.Retrieved24 August2018.
  16. ^Apache Tomcat Project."Apache Tomcat".Retrieved21 September2015.
  17. ^"The Jakarta Site - News and Status".Retrieved21 September2015.
  18. ^Apache Tomcat Project."Apache Tomcat".Retrieved2022-03-28.
  19. ^"[ANN] Apache Tomcat 6.0.10 released".Retrieved21 September2015.
  20. ^"Apache Tomcat - End of life for Apache Tomcat 6.0.x".tomcat.apache.org.Retrieved2020-07-20.
  21. ^Apache Tomcat Project."Apache Tomcat".Retrieved21 September2015.
  22. ^"Apache Tomcat 7 (7.0.109) - Changelog".tomcat.apache.org.Retrieved2021-06-17.
  23. ^"Apache Tomcat - End of life for Apache Tomcat 7.0.x".tomcat.apache.org.Retrieved2020-07-20.
  24. ^Apache Tomcat Project."Apache Tomcat".Retrieved5 October2015.
  25. ^"Apache Tomcat - End of life for Apache Tomcat 8.0.x".tomcat.apache.org.Retrieved2020-07-20.
  26. ^Apache Tomcat Project."Apache Tomcat 8.5 Changelog".Retrieved2024-04-07.
  27. ^"Apache Tomcat - End of life for Apache Tomcat 8.5.x".tomcat.apache.org.Retrieved2023-10-16.
  28. ^Apache Tomcat Project."Apache Tomcat 9.0 Changelog".Retrieved2024-04-07.
  29. ^Apache Tomcat Project."Apache Tomcat 10.0 Changelog".Retrieved2023-05-09.
  30. ^"Apache Tomcat - End of life for Apache Tomcat 10.0.x".tomcat.apache.org.Retrieved2022-11-17.
  31. ^Apache Tomcat Project."Apache Tomcat 10.1 Changelog".Retrieved2024-04-07.
  32. ^Apache Tomcat Project."Apache Tomcat 11.0 Changelog".Retrieved2024-04-07.
  33. ^"Apache TomEE".Apache OpenEJB.
  34. ^"The Apache Software Foundation Announces Apache TomEE Certified as Java EE 6 Web Profile Compatible".MarketWatch.4 Oct 2011.
  35. ^"Apache TomEE Web stack gains approval".InfoWorld.7 Oct 2011.

Bibliography

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