Spring Framework: Difference between revisions

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{{About|the Spring Framework|the Spring Boot|Spring Boot||}}
{{Short description|Application framework for Java platform}}
{{Infobox software
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| license = [[Apache License]] 2.0
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The '''Spring Framework''' is an [[application framework]] and [[inversion of control]] [[Servlet container|container]] for the [[Java platform]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2 Spring Core Tasks | p=47}} The framework's core features can be used by any Java application, but there are extensions for building [[web application]]s on top of the [[Java EE]] (Enterprise Edition) platform. The framework does not impose any specific [[programming model]].{{Citation needed|reason=Spring Web Flux Framework heavily uses the functional-programming paradigm according to Deinum and Cosmina's "Pro Spring MVC with WebFlux". Need supporting information for the claim that the framework does not impose any specific programming model|date=June 2023}}. The framework has become popular in the Java community as an addition to the [[Enterprise JavaBeans]] (EJB) model.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§16-2 Integrating Two Systems Using JMS | pp=694-698}} The Spring Framework is [[OpenFree and open-source software|free and open source software]].{{sfn|Johnson|Hoeller|2004}}{{rp | pp=121–122}}{{sfn|Deinum|Cosmina|2021|loc=§1 Setting up a Local Development Environment | p=1}}
 
==Version history==
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! Version
! Date
! Notes
|-
| 0.9 || 2003
| 2003
|-
| 1.0 || March 24, 2004
| March 24, 2004
| First production release.
|-
| 2.0 || 2006
| 2006
|-
| 3.0 || 2009
| 2009
|
|-
| 4.0 || 2013
| 2013
|
|-
| 5.0 || 2017
| 2017
|
|-
| 6.0 || November 1622, 2022
| 6.0
|-
| November 16, 2022
| 6.1 || November 16, 2023
|
|-
| 6.2 || November 14, 2024
|-
|}
 
The first version was written by [[Rod Johnson (programmer)|Rod Johnson]], who released the framework with the publication of his book ''Expert One-on-One J2EE Design and Development'' in October 2002. The framework was first released under the [[Apache License|Apache 2.0 license]] in June 2003. The first production release, 1.0, was released in March 2004.<ref>{{cite web |url=https://spring.io/blog/2004/03/24/spring-framework-1-0-final-released | date=24 March 2014 | title=Spring Framework 1.0 Final Released | website=Official Spring Framework blog |access-date=1 March 2021}}</ref> The Spring 1.2.6 framework won a [[Jolt Awards|Jolt productivity award]] and a [[JAX Innovation Award]] in 2006.<ref>[http://www.ddj.com/architect/187900423?pgno=10 Jolt winners 2006]</ref><ref>{{Cite web |url=http://jax-award.de/jax_award06/gewinner_de.php |title=JAX Innovation Award Gewinner 2006 |access-date=2009-08-12 |archive-url=https://web.archive.org/web/20090817202514/http://jax-award.de/jax_award06/gewinner_de.php |archive-date=2009-08-17 |url-status=dead }}</ref> Spring 2.0 was released in October 2006, Spring 2.5 in November 2007, Spring 3.0 in December 2009, Spring 3.1 in December 2011, and Spring 3.2.5 in November 2013.<ref>{{cite web |url=https://spring.io/blog/2013/11/07/spring-framework-3-2-5-released |date=7 Nov 2013 | title=Spring Framework 3.2.5 Released | website=Official Spring website | access-date=16 October 2016}}</ref> Spring Framework 4.0 was released in December 2013.<ref>{{cite web|url=https://spring.io/blog/2013/12/12/announcing-spring-framework-4-0-ga-release/|title=Announcing Spring Framework 4.0 GA Release|publisher=Spring blog|date=12 December 2013}}</ref> Notable improvements in Spring 4.0 included support for Java SE (Standard Edition) 8, [[Groovy (programming language)|Groovy]] 2,{{sfn | Walls | 2016 | loc=§5 | pp=92-106}}{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§4 Spring Configuration in Detail and Spring Boot | pp=125-126 }} some aspects of Java EE 7, and [[WebSocket]].{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc = §1 Introducing Spring | pp=1-18}}
{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§4 Spring Configuration in Detail and Spring Boot | pp=125-126 }} some aspects of Java EE 7, and [[WebSocket]].
{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc = §1 Introducing Spring | pp=1-18}}
 
Spring Boot 1.0 was released in April 2014.<ref>{{cite web|url=https://github.com/spring-projects/spring-boot/releases/tag/v1.0.0.RELEASE|title=Spring Boot v1.0.0.RELEASE|publisher=github.com}}</ref>
 
Spring Framework 4.2.0 was released on 31 July 2015 and was immediately upgraded to version 4.2.1, which was released on 01 Sept 2015.<ref>{{cite web|url=http://spring.io/blog/2015/07/31/spring-framework-4-2-goes-ga|title=Spring Framework 4.2 goes GA|publisher=Spring Blog|date=31 July 2015}}</ref> It is ''"compatible with Java 6, 7 and 8, with a focus on core refinements and modern web capabilities"''.<ref name="spring-4.2">{{cite web|url=http://spring.io/blog/2015/07/31/spring-framework-4-2-goes-ga|title=Spring Framework 4.2 goes GA|publisher=Spring Blog}}</ref>
 
Spring Framework 4.3 has been released on 10 June 2016 and will bewas supported until 2020.<ref>{{cite web|url=https://github.com/spring-projects/spring-framework/wiki/Upgrading-to-Spring-Framework-5.xVersions#supported-versions|title=Upgrading to Spring Framework 5.xVersions: Supported Versions|website=github.com}}</ref> It was announced to ''"will be the final generation within the general Spring 4 system requirements (Java 6+, Servlet 2.5+), [...]"''.<ref name="spring-4.2"/>
 
Spring 5 is announced to be built upon [[Reactive Streams]] compatible Reactor Core.<ref>{{cite web|url=http://spring.io/blog/2016/02/09/reactive-spring|title=Reactive Spring|publisher=Spring Blog|date=9 February 2016}}</ref>{{Obsolete source|reason=This source is from 2016, but Spring 5.0.x was already released and was called "a major release" in the book "Pro Spring 5" by Iuliana Cosmina, Rob Harrop, Chris Schaefer and Clarence Ho|date=June 2023}}
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==Modules==
The Spring Framework includes several modules that provide a range of services:
* Spring Core Container: this is the base module of Spring{{sfn | Walls | 2019 | p=48}} and provides spring containers (<code>BeanFactory</code> and <code>ApplicationContext</code>).<ref>[http://docs.spring.io/spring-framework/docs/current/spring-framework-reference/html/beans.html#beans-introduction Spring Framework documentation for the Core Container]</ref>{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §2 - The Bean Factory and ApplicationContext}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-1 Using Java Config to configure POJOs | p=137}} In this context, <code>spring-core</code> is the artifact{{sfn | Johnson | Hoeller | 2004 | loc=Introducing the Spring Framework - The Core Bean Factory | p=150}} found in the core module{{sfn | Deinum | Cosmina | 2021 | loc=§2 Spring Framework Fundamentals - The Spring Framework | pp=22-25}} belonging to the <code>org.springframework</code> group.{{sfn | Walls | 2016 | loc=§Appendix D Spring Boot dependencies | p=240}} The <code>spring-core</code> artifact consists of the IoC container, as well as the utility classes{{sfn | Johnson | Hoeller | 2004 | loc=Introducing the Spring Framework - The Core Bean Factory | p=150}} used throughout the application.{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §1 Introducing the Spring Framework - Module Summary}}
* [[Aspect-oriented programming]]: enables implementing [[cross-cutting concern]]s.{{sfn|Johnson|Höller|Arendsen|Risberg|2005|loc=Chapter §4 - Spring and AOP}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-17 AOP introductions for POJOs | pp=196-198}} The <code>spring-aop</code> is an artifact for the AOP framework.{{sfn | Deinum | Cosmina | 2021 | loc=§2 Spring Framework Fundamentals - The Spring Framework | pp=22-25}}
* [[Authentication]] and [[authorization]]: configurable security processes that support a range of standards, protocols, tools and practices via the [[Spring Security]] sub-project (formerly Acegi Security System for Spring).{{sfn|Johnson|Höller|Arendsen|Risberg|2005|loc=Acegi Security System for Spring}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§7 Spring Security | p=331}}
* [[Convention over configuration]]: a rapid application development solution for Spring-based enterprise applications is offered in the [[Spring Roo]] module.
* [[Data access]]: working with [[RDBMS|relational database management systems]] on the Java platform using [[Java Database Connectivity]] (JDBC){{sfn|Walls|2019|pp=56-59}} and [[object-relational mapping]] tools and with [[NoSQL]]{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}} databases. The <code>spring-jdbc</code> is an artifact found in the JDBC module whilewhich supports JDBC access by including datasource setup classes.{{sfn | Deinum | Cosmina | 2021 | loc=§2 Spring Framework Fundamentals - The Spring Framework | pp=22-25}}
* [[Inversion of control]] container: configuration of application components and lifecycle management of Java objects, done mainly via [[dependency injection]].{{sfn|Johnson|Höller|Arendsen|Risberg|2005|loc=Chapter §2 - The Bean Factory and ApplicationContext}}
* Messaging: declarative registration of message listener objects for transparent message-consumption from [[message queue]]s via [[Java Message Service]] (JMS), improvement of message sending over standard JMS APIs.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§15-4 Create Message-Driven POJOs in Spring | pp=677-681}}
* [[Model–view–controller]]: an [[HTTP]]- and [[Java Servlet API|servlet]]-based framework providing hooks for extension and customization for web applications and [[REST]]ful (representational state transfer) Web services.{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §12 - Web MVC Framework}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4 Spring @MVC | p=217}}
* Remote access framework: declarative [[remote procedure call]] (RPC)-style{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-3 Writing a Custom ItemWriter and ItemReader | pp=525-534}} [[Marshalling (computer science)|marshalling]] of Java objects over networks supporting [[Java remote method invocation]] (RMI),{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-7 Expose and Invoke Services through RMI; §14-8 Expose and Invoke Services through HTTP | pp=627-632}} [[CORBA]] (Common Object Request Broker Architecture) and [[HTTP]]-based protocols including [[Web services]] such as [[SOAP (protocol)|SOAP (Simple Object Access Protocol)]]).{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-10 Introduction to contract first SOAP Web Services,§14-11 Expose and invoke SOAP Web Services with Spring-WS,§14-12 Develop SOAP Web Services with Spring-WS and XML
Marshalling|pp=641-658}}{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §8 - Lightweight Remoting}}
* [[Transaction processing|Transaction management]]: unifies several transaction management APIs and coordinates transactions for Java objects.{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §9 - Supporting Services}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11 Spring Transaction Management | p=475}}
* Remote management: declarative exposure and management of Java objects for local or remote configuration via [[Java Management Extensions]] (JMX).{{sfn | Johnson | Höller | Arendsen | Risberg | 2005 | loc=Chapter §9 - Supporting Services}}{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14 Spring Java Enterprise Services and Remoting Technologies | p=591}}
* [[Software testing|Testing]]: support classes for writing [[Unit testing|unit test]]s{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§17-3 Unit Testing Spring MVC Controllers | pp=737-739}} and [[Integration testing|integration test]]s.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§17-4 Managing Application Contexts in Integration Tests | pp=739-743}}
* WebFlux support: support for using reactive runtimes or web servers such as UnderTow and [[Netty (software)|Netty]].{{sfn | Deinum | Cosmina | 2021 | loc=§2 Spring Framework Fundamentals - The Spring Framework | pp=22-25}}{{sfn | Musib | 2022 | loc=§8.3 Introducing Spring WebFlux | p=358}}
* Web Socket support: Support for communicating using the WebSocket protocol. The artifact for this module is <code>spring-websocket</code>.
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Spring modules are packaged as JAR files.{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | p=21-23}} These artifacts can be accessed via the Maven Central Repository using [[Apache Maven|Maven]]{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§2 Accessing Spring Modules Using Maven | pp=24-25}} or [[Gradle]].{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§2 Accessing Spring Modules Using Gradle| p=26}}
 
=== Inversion of control container ===
The [[inversion of control]] (IoC) container is the core container in the Spring Framework.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2 Spring Core Tasks | p=47}} It provides a consistent means of configuring and managing Java objects{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2 Spring Core Tasks | p=47}}{{sfn|Johnson|Hoeller|2004}}{{rp|pp=127–131}} using [[Reflection (computer science)|reflection]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-2 Create POJOs by Invoking a Constructor|pp=53-62}} The container is responsible for managing [[Object lifetime|object lifecycles]] of specific objects:{{sfn|Johnson|Hoeller|2004}}{{rp | p=128}} creating these objects,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-1 Manage and Configure POJOs with the Spring IoC Container|pp=48-52}} calling their [[Initialization (programming)|initialization]] methods,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-2 Create POJOs by Invoking a Constructor|pp=53-62}} and configuring these objects by wiring them together.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-3 Use POJO References, Auto-Wiring, and Imports to Interact with Other POJOs|pp=59-67}}
 
In many cases, one need not use the container when using other parts of the Spring Framework, although using it will likely make an application easier to configure and customize. The Spring container provides a consistent mechanism to configure applications{{sfn | Johnson | Hoeller | 2004}}{{rp | p=122}} and integrates with almost all Java environments, from small-scale applications to large enterprise applications.
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====Creating and managing beans====
Objects created by the container are called managed objects or [[JavaBeans|beans]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-16 Use Property Editors in Spring|pp=112-116}} The container can be configured by loading [[XML]] (Extensible Markup Language) files{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-1 Manage and Configure POJOs with the Spring IoC Container | pp=48-52}}{{sfn | Johnson | Hoeller | 2004}}{{rp|pp=151–152}} or detecting specific [[Java annotation]]s on configuration classes. These data sources contain the bean definitions that provide the information required to create the beans.
 
The {{code|@Configuration}} is a Spring-specific annotation that marks a class as the configuration class. thatThe configuration class provides the beans to the Spring {{code|ApplicationContext}}.{{sfn|Walls|2019|loc=§1.1 Getting started with Spring - What is Spring|pp=4-6}} Each of the methods in the Spring configuration class is configured with the {{code|@Bean}} annotation,. which informs theThe {{code|ApplicationContext}} tointerface will then return the objects configured with the {{code|@Bean}} annotation as beans. The advantage of javaJava-based configuration over XML-based configuration is better type safety and refactorability.{{sfn|Walls|2019|loc=§1.1 Getting started with Spring - What is Spring | pp=4-6}}
 
==== Types of Inversion of Control ====
There are several types of Inversion of Control. Dependency injection and dependency lookup are examples of Inversion of Control.{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§3 Introducing IoC and DI in Spring | p=37}} Objects can be obtained by means of either dependency lookup or dependency injection.{{sfn | Johnson | Hoeller | 2004}}{{rp | p=127}}<ref>[http://forum.springsource.org/showthread.php?79731-What-is-the-difference-between-the-depencylookup-and-dependency-injection What is the difference between the depencylookup and dependency injection - Spring Forum]. Forum.springsource.org (2009-10-28). Retrieved on 2013-11-24.</ref>
 
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====Autowiring====
The Spring framework has a feature known as autowiring, which useuses the springSpring container to automatically satisfy the dependencies specified in the JavaBean properties to objects of the appropriate type in the current factory.{{sfn | Johnson | Hoeller | 2004 | loc=§6 Lightweight Containers and Inversion of Control - IOC Containers | pp=135–137}} This can only occur if there is only one object with the appropriate type.{{sfn | Johnson | Hoeller | 2004 | loc=§6 Lightweight Containers and Inversion of Control - IOC Containers | pp=135–137}}
 
There are several annotations that can be used for autowiring POJOs, including the Spring-specific annotation {{code|@Autowire}} (as well as several other Spring-specific annotations that help resolve autowire ambiguity such as the {{code|@Qualifier}} or {{code|@Primary}} annotations),{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-3 Use POJO References and Auto-Wiring to Interact with other POJOs |pp=145-151}}{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§3 Introducing IoC and DI in Spring - Autowiring Your Beans | pp=112-120 }} and the standard Java annotations {{code|@Resource}} and {{code|@Inject}}.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-4 Auto-wire POJOs the @Resource and @Inject annotation | pp=151-154}}
 
The {{code|@Qualifier}} annotation is a Spring can be used on a class that defines a bean to inform Spring to prioritize the bean creation when autowiring it by '''name'''.{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§3 Introducing IoC and DI in Spring - Autowiring Your Beans | pp=112-120 }}
 
The {{code|@Primary}} annotation can be used on a class that defines a bean to inform Spring to prioritize the bean creation when autowiring it by '''type'''.{{sfn | Cosmina | Harrop | Schaefer | Ho | 2017 | loc=§3 Introducing IoC and DI in Spring - Autowiring Your Beans | pp=112-120 }}
 
The {{code|@Resource}} annotation is an annotation that conforms to [[JSR 250]], or Common Annotations for the Java Platform, and allowsis used for autowiring references to POJOs by '''name'''.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-4 Auto-wire POJOs the @Resource and @Inject annotation | pp=151-154}}

The {{code|@Inject}} annotation is an annotation that conforms to JSR 300, or Standard Annotations for injection, and is allowsused for autowiring references to POJOs by '''type'''.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§3-4 Auto-wire POJOs the @Resource and @Inject annotation | pp=151-154}}
 
===Aspect-oriented programming framework===
{{main article | Aspect-oriented programming}}
The Spring Framework has its own [[Aspect-oriented programming]] (AOP) framework that modularizes cross-cutting concerns in [[Aspect (computer science)|aspects]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§2-12 Aspect Orientated Programming |pp=99-104}} The motivation for creating a separate AOP framework is to provide basic AOP features without too much complexity in either design, implementation, or configuration. The Spring AOP framework takes full advantage of the Spring container.
 
The Spring AOP framework is [[Proxy pattern|proxy pattern-based]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-6 Managing Transactions Declaratively with the @Transactional Annotation | pp=492-494}}{{sfn | Deinum | Cosmina | 2021 | loc=§2 Spring Framework Fundamentals - The Spring Framework | pp=22-25}} It is configured at [[run time (program lifecycle phase)|run time]].{{Citation needed|date=June 2023}} This removes the need for a compilation step or load-time weaving.{{Citation needed|date=June 2023}} On the other hand, interception only allows for public method-execution on existing objects at a [[join point]].{{Citation needed|date=June 2023}}
 
Compared to the [[AspectJ]] framework, Spring AOP is less powerful, but also less complicated.{{Citation needed|date=June 2023}} Spring 1.2 includes support to configure AspectJ aspects in the container. Spring 2.0 added more integration with AspectJ; for example, the [[pointcut]] language is reused and can be mixed with Spring AOP-based aspects.{{Citation needed|date=June 2023}} Further, Spring 2.0 added a Spring Aspects library that uses AspectJ to offer common Spring features such as declarative transaction management{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-6 Managing Transactions Declaratively with the @Transactional Annotation | pp=492-494}} and dependency injection via AspectJ compile-time or load-time weaving.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-11 Managing Transactions with Load-Time Weaving | pp=509-510}} [[SpringSource]] uses AspectJ AOP in other Spring projects such as Spring Roo and Spring Insight, with Spring Security offering an AspectJ-based aspect library.{{Citation needed|date=June 2023}}
 
Spring AOP has been designed to work with cross-cutting concerns inside the Spring Framework.{{sfn | Johnson | Hoeller | 2004}}{{rp | p=473}} Any object which is created and configured by the container can be enriched using Spring AOP.
 
The Spring Framework uses Spring AOP internally for transaction management, security, remote access, and [[Java Management Extensions|JMX]].<ref>{{Citationcite book |last=Chidester |first=Ashlan |title=Looking Forward to the Spring Framework needed|date=June2024 |publisher=Kindle Edition |url=https://www.amazon.com/dp/B0CFYBPFLQ?ref=KC_GS_GB_US |access-date=February 12, 20232025}}</ref>
 
Since version 2.0 of the framework, Spring provides two approaches to the AOP configuration:
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===Data access framework===
Spring's data access framework addresses common difficulties developers face when working with databases in applications. Support is provided for all popular data access frameworks in Java: JDBC, [[IBATIS|iBatis]]/[[MyBatis]],{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}} [[Hibernate (Java)|Hibernate]],{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}} [[Java Data Objects]] (JDO, discontinued since 5.x),{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}} [[Java Persistence API|Jakarta Persistence API]] (JPA),{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}} [[TopLink|Oracle TopLink]], [[Ojb|Apache OJB]], and [[Apache Cayenne]], among others.
 
For all of these supported frameworks, Spring provides these features
 
* Resource management – automatically acquiring and releasing database resources
* Exception handling – translating data access related exception to a Spring data access hierarchy{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10-5 Handling Exceptions in the Spring JDBC Framework | pp=441-446}}
* Transaction participation – transparent participation in ongoing transactions{{sfn | Johnson | Hoeller | 2004}}{{rp|pp=290–291}}
* Resource unwrapping – retrieving database objects from connection pool wrappers
* Abstraction for [[binary large object]] (BLOB) and [[character large object]] (CLOB) handling
 
All these features become available when using [[Template method pattern|template classes]] provided by Spring for each supported framework.{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|pp=426-441,463-465}} Critics have said these template classes are intrusive and offer no advantage over using (for example) the Hibernate API directly.<ref>[http://houseofhaug.wordpress.com/2005/08/12/hibernate-hates-spring Hibernate VS Spring]</ref>{{Failed verification|date=January 2012}} In response, the Spring developers have made it possible to use the Hibernate and JPA APIs directly. This however requires transparent transaction management, as application code no longer assumes the responsibility to obtain and close database resources,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10-8 Persisting Objects with Spring's ORM Templates | pp=463-466}} and does not support exception translation.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10-6 Problems with Using ORM Frameworks Directly | pp=446-462}}
 
Together with Spring's transaction management, its data access framework offers a flexible abstraction for working with data access frameworks. The Spring Framework doesn't offer a common data access API; instead, the full power of the supported APIs is kept intact.{{Citation needed|date=June 2023}} The Spring Framework is the only framework available in Java that offers managed data access environments outside of an application server or container.<ref>
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While using Spring for transaction management with Hibernate, the following beans may have to be configured:
* A <code>[[Datasource]]</code> like <code>com.mchange.v2.c3p0.ComboPooledDataSource</code> or <code>org.apache.commons.dbcp.BasicDataSource</code>{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10 Data Access | pp=419-426}}
* A <code>SessionFactory</code> like <code>org.springframework.orm.hibernate3.LocalSessionFactoryBean</code> with a <code>DataSource</code> attribute{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10-7 Configuring ORM Resource Factories in Spring | pp=456-460}}{{sfn | Johnson | Hoeller | 2004}}{{rp|p=173}}
* A <code>HibernateProperties</code>{{sfn | Johnson | Hoeller | 2004}}{{rp|p=173}} like <code>org.springframework.beans.factory.config.PropertiesFactoryBean</code>
* A <code>TransactionManager</code> like <code>org.springframework.orm.hibernate3.HibernateTransactionManager</code> with a <code>SessionFactory</code> attribute{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§10-7 Configuring ORM Resource Factories in Spring | pp=456-460}}
Other points of configuration include:
* An AOP configuration of cutting points.
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===Transaction management===
Spring's transaction management framework brings an abstraction mechanism to the Java platform.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-2 Choosing a Transaction Manager Implementation|pp=464-468}} Its abstraction is capable of:
* working with local and [[distributed transaction|global transaction]]s{{sfn | Johnson | Hoeller | 2004}}{{rp | p=258}} (local transaction does not require an [[application server]])
* working with [[nested transaction]]s{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-7 Setting the Propagation Transaction Attribute|pp=494-499}}
* working with [[savepoint]]s{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-7 Setting the Propagation Transaction Attribute | pp=494-499}}
* working in almost all environments of the Java platform
 
In comparison, [[Java Transaction API]] (JTA) only supports nested transactions and global transactions, and requires an application server (and in some cases, deployment of applications in an application server).
 
The Spring Framework ships a <code>PlatformTransactionManager</code>{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-2 Choosing a Transaction Manager Implementation | pp=482-484}} for a number of transaction management strategies:
* Transactions managed on a JDBC Connection{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-2 Choosing a Transaction Manager Implementation|pp=464-468}}
* Transactions managed on Object-relational mapping Units of Work{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-2 Choosing a Transaction Manager Implementation|pp=464-468}}
* Transactions managed via the JTA {{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-2 Choosing a Transaction Manager Implementation|pp=464-468}}<code>JtaTransactionManager</code>{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-3 Managing Transactions Programmatically with the Transaction Manager API|pp=484-486}}{{sfn | Johnson | Hoeller | 2004}}{{rp | pp=255–257}} and <code>UserTransaction</code>{{sfn | Johnson | Hoeller | 2004}}{{rp | p=234}}
* Transactions managed on other resources, like [[object database]]s
 
Next to this abstraction mechanism the framework provides two ways of adding transaction management to applications:
* Procedurally, by using Spring's <code>TransactionTemplate</code>{{sfn |Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-4 Managing Transactions Programmatically with a Transaction Template | pp=486-489}}
* Declaratively, by using [[metadata]] like XML or Java annotations (<code>@Transactional</code>,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§11-6 Managing Transactions Declaratively with the @Transactional Annotation | pp=492-494}} etc.)
 
Together with Spring's data access framework &ndash; which integrates the transaction management framework &ndash; it is possible to set up a transactional system through configuration without having to rely on JTA or [[EJB]]. The transactional framework also integrates with messaging{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§15-4 Create Message-Driven POJOs in Spring | pp=677-685}} and [[cache (computing)|caching]]{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§15-5 Cache and pool JMS connections | pp=685-686}} engines.
 
===Model–view–controller framework===
[[File:Spring5JuergenHoeller2.jpg|thumb|Spring MVC/Web Reactive presentation given by Jürgen Höller]]
The Spring Framework features its own [[model–view–controller]] (MVC) [[web application framework]],{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4 Spring @MVC | p=217}} which was not originally planned. The Spring developers decided to write their own Web framework as a reaction to what they perceived as the poor design of the (then) popular [[Jakarta Struts]] Web framework,<ref>[http://www.theserverside.com/tt/articles/article.tss?l=SpringFramework Introduction to the Spring Framework]</ref>{{Failed verification|date=June 2023}} as well as deficiencies in other available frameworks. In particular, they felt there was insufficient separation between the presentation and request handling layers, and between the request handling layer and the model.<ref>Johnson, Expert One-on-One J2EE Design and Development, Ch.&nbsp;12. et al.</ref>
 
Like Struts, Spring MVC is a request-based framework.{{sfn | Johnson | Hoeller | 2004}}{{rp | p=375}} The framework defines [[strategy pattern|strategy]] interfaces{{sfn | Johnson | Hoeller | 2004}}{{rp | p=144}} for all of the responsibilities that must be handled by a modern request-based framework. The goal of each interface is to be simple and clear so that it's easy for Spring MVC users to write their own implementations, if they so choose. MVC paves the way for cleaner front end code. All interfaces are tightly coupled to the [[Java Servlet|Servlet API]]. This tight coupling to the Servlet API is seen by some as a failure on the part of the Spring developers to offer a high level of abstraction for Web-based applications {{Citation needed|date=February 2007}}. However, this coupling ensures that the features of the Servlet API remain available to developers while offering a high abstraction framework to ease working with it.
 
The <code>DispatcherServlet</code> class is the [[front controller]]<ref>Patterns of Enterprise Application Architecture: [http://www.martinfowler.com/eaaCatalog/frontController.html Front Controller]</ref> of the framework and is responsible for delegating control to the various interfaces during the execution phases of an [[Hypertext Transfer Protocol|HTTP request]].{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}}
 
The most important interfaces defined by Spring MVC, and their responsibilities, are listed below:{{sfn | Deinum | Cosmina | 2021 | loc=§4 Spring MVC Architecture - The Request Processing Summary | pp=82-83}}
* <code>Controller</code>: comes between <code>Model</code> and <code>View</code> to manage incoming requests and redirect to proper response.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-219}} <code>Controller</code> will map the http request to corresponding methods.{{sfn|Walls|2019|pp=18-19}} It acts as a gate that directs the incoming information. It switches between going into <code>Model</code> or <code>View</code>.
* <code>HandlerAdapter</code>: responsible for execution of objects that handle incoming requests.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-3 Intercepting Requests with Handler Interceptors|pp=236-239}}
* <code>HandlerInterceptor</code>: responsible for intercepting incoming requests.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-3 Intercepting Requests with Handler Interceptors | pp=236-239}} Comparable, but not equal to Servlet filters{{sfn | Johnson | Hoeller | 2004}}{{rp | p=509}} (use is optional{{sfn | Johnson | Hoeller | 2004}}{{rp | p=511}} and not controlled by <code>DispatcherServlet</code>).
* <code>HandlerMapping</code>: responsible for selecting objects that handle incoming requests (handlers) based on any attribute or condition internal or external to those requests{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC | pp=217-232}}
* <code>LocaleResolver</code>: responsible for resolving and optionally saving of the [[locale (computer software)|locale]] of an individual user.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-4 Resolving User Locales | pp=239-240}}
* <code>MultipartResolver</code>: facilitate working with file uploads by wrapping incoming requests.{{sfn | Deinum | Cosmina | 2021 | loc=§4 Spring MVC Architecture - Prepare a request | pp=75-76}}
* <code>View</code>: responsible for returning a response to the client. The <code>View</code> should not contain any business logic and should only present the data encapsulated by the <code>Model</code>.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4 Spring @MVC | p=217}} Some requests may go straight to <code>View</code> without going to the <code>Model</code> part; others may go through all three.
* <code>ViewResolver</code>: responsible for selecting a <code>View</code> based on a logical name for the <code>View</code>{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-6 Resolving Views by Names|pp=243-247}}{{sfn | Deinum | Cosmina | 2021 | loc=§4 Spring MVC Architecture - Render a view | p=81}} (use is not strictly required{{sfn | Johnson | Hoeller | 2004}}{{rp | p=511}}).
* <code>Model</code>: responsible for encapsulating business data.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-6 Resolving Views by Names|pp=243-247}} The <code>Model</code> is exposed to the view by the controller.{{sfn | Johnson | Hoeller | 2004}}{{rp | p=374}} (use is not strictly required).
 
Each strategy interface above has an important responsibility in the overall framework. The abstractions offered by these interfaces are powerful, so to allow for a set of variations in their implementations.{{sfn | Johnson | Hoeller | 2004}}{{rp | p=144}} Spring MVC ships with implementations of all these interfaces and offers a feature set on top of the Servlet API. However, developers and vendors are free to write other implementations. Spring MVC uses the Java {{Javadoc:SE|package=java.util|java/util|Map}} interface as a data-oriented abstraction for the <code>Model</code> where keys are expected to be {{Javadoc:SE|java/lang|String}} values.{{Citation needed|date=June 2023}}
 
The ease of testing the implementations of these interfaces is one important advantage of the high level of abstraction offered by Spring MVC.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§17 Spring Testing | p=723}}{{sfn | Johnson | Hoeller | 2004}}{{rp | p=324}} <code>DispatcherServlet</code> is tightly coupled to the Spring inversion of control container for configuring the web layers of applications. However, web applications can use other parts of the Spring Framework, including the container, and choose not to use Spring MVC.
 
====A workflow of Spring MVC====
When a user clicks a link or submits a form in their web-browser, the request goes to the Spring <code>DispatcherServlet</code>. <code>DispatcherServlet</code> is a [[Front controller|front-controller]] in Spring MVC.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}}{{sfn | Deinum | Cosmina | 2021 | loc=§4 Spring MVC Architecture - DispatcherServlet Request Processing Workflow|pp=73-74}} The <code>DispatcherServlet</code> is highly customizable and flexible.{{sfn|Deinum|Cosmina|2021|loc=§4 Spring MVC Architecture - DispatcherServlet Request Processing Workflow|pp=73-74}} Specifically, it is capable of handling more types of handlers than any implementations of <code>org.
springframework.web.servlet.mvc.Controller</code> or <code>org.
springframework.stereotype.Controller</code> annotated classes.{{sfn|Deinum|Cosmina|2021|loc=§4 Spring MVC Architecture - DispatcherServlet Request Processing Workflow|pp=73-74}} It consults one or more handler mappings.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}} <code>DispatcherServlet</code> chooses an appropriate controller and forwards the request to it. The <code>Controller</code> processes the particular request and generates a result. It is known as <code>Model</code>. This information needs to be formatted in html or any front-end technology like [[Jakarta Server Pages]] (also known as JSP){{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}}{{sfn|Walls|2019 | p=35}} or [[Thymeleaf]].{{sfn|Walls|2019 | p=35}} This is the <code>View</code> of an application.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}} All of the information is in the <code>Model</code> And <code>View</code> object. When the controller is not coupled to a particular view, <code>DispatcherServlet</code> finds the actual <code>View</code> (such as JSP) with the help of <code>ViewResolver</code>.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§4-1 Developing a Simple Web Application with Spring MVC|pp=217-232}}{{sfn | Johnson | Hoeller | 2004}}{{rp | pp=390–391}}
 
====Configuration of DispatcherServlet====
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* By using <code>javax.servlet.ServletContainerInitializer</code>{{sfn|Deinum|Cosmina|2021|loc=§4 Spring MVC Architecture - Bootstrapping DispatcherServlet|pp=84-90}}
* By implementing the <code> org.springframework.web.WebApplicationInitializer</code> interface.{{sfn|Deinum|Cosmina|2021|loc=§4 Spring MVC Architecture - Bootstrapping DispatcherServlet|pp=84-90}}
* By using the built-in autoconfiguration for Spring Boot, which uses the <code>[[Spring Boot#Bootstrapping DispatcherServlet|SpringBootServletInitializer]]</code> class.lm{{sfn|Deinum|Cosmina|2021|loc=§4 Spring MVC Architecture - Bootstrapping DispatcherServlet|pp=84-90}}
 
===Remote access framework===
Spring's Remote Access framework is an abstraction for working with various RPC ([[remote procedure call]])-based technologies available on the Java platform both for client connectivity and marshalling objects on servers.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-7 Expose and Invoke Services through RMI|pp=627-632}} The most important feature offered by this framework is to ease configuration and usage of these technologies as much as possible by combining inversion of control and AOP.
 
The framework provides fault-recovery (automatic reconnection after connection failure) and some optimizations for client-side use of EJB remote [[Stateless Session Bean|stateless session beans]].
Line 267 ⟶ 256:
 
* HTTP-based protocols
** [[Hessian (Web service protocol)|Hessian]]: binary serialization protocol,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-8 Expose and Invoke Services through HTTP|pp=632-635}}{{sfn | Johnson | Hoeller | 2004}}{{rp | p=335}} open-sourced{{sfn | Johnson | Hoeller | 2004}}{{rp | p=335}} and maintained by [[Common Object Request Broker Architecture|CORBA]]-based protocols{{Citation needed|reason=Sources such as "Expert One-on-One J2EE Design and Development" by Rod Johnson or "Spring Recipes" by Deinum et Al. only mention that the Hessian is maintained by the company "Caucho" and they do not explicity mention that the Hessian is maintained by CORBA-based protocols|date=June 2023}}. Hessian is maintained by the company [[Caucho Technology|Caucho]].{{sfn | Johnson | Hoeller | 2004}}{{rp | p=335}} Hessian is suitable for stateless remoting needs, in particular, Java-to-Java communication.{{sfn | Johnson | Hoeller | 2004}}{{rp|pp=335–336}}
** Burlap: An [[Xml based language|XML-based]] binary protocol that is open-sourced and also maintained by the company [[Caucho Technology|Caucho]].{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§14-8 Expose and Invoke Services through HTTP|pp=632-635}}{{sfn | Johnson | Hoeller | 2004}}{{rp | p=335}} The only advantage of using Burlap instead of Hessian is that it is [[XML parser|XML-parsable]] and [[Human readable code|human readable]].{{sfn | Johnson | Hoeller | 2004}}{{rp | p=335}} For Java-to-Java communication, the Hessian is preferred since it is more light-weight and efficient.{{sfn|Johnson|Hoeller|2004}}{{rp | p=335}}
** [[Java remote method invocation|RMI]] (1): method invocations using RMI infrastructure yet specific to Spring{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-7 Expose and Invoke Services through RMI|pp=627-632}}
** RMI (2): method invocations using RMI interfaces complying with regular RMI usage{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-7 Expose and Invoke Services through RMI|pp=627-632}}
** [[RMI-IIOP]] ([[Common Object Request Broker Architecture|CORBA]]): method invocations using RMI-IIOP/CORBA
* [[Enterprise JavaBean]] client integration{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§16-1 Integrating One System with Another Using EAI|pp=692-694}}
** Local EJB stateless session bean connectivity: connecting to local stateless session beans
** Remote EJB stateless session bean connectivity: connecting to remote stateless session beans
* SOAP
** Integration with the [[Apache Axis]] Web services framework{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-9 Expose and invoke SOAP Web Services with JAX-WS|pp=635-641}}
 
[[Apache CXF]] provides integration with the Spring Framework for RPC-style exporting of objects on the server side.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§14-9 Expose and invoke SOAP Web Services with JAX-WS|pp=635-641}}
 
Both client and server setup for all RPC-style protocols and products supported by the Spring Remote access framework (except for the Apache Axis support) is configured in the Spring Core container.
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====Spring Boot====
{{main article|Spring Boot}}
[[Spring Boot]] Extension is Spring's [[Convention over configuration|convention-over-configuration]] solution for creating [[standaloneStandalone applicationprogram|stand-alone]], production-grade{{sfn|Walls|2016|loc=§foreword | p=vii}} Spring-based Applications that you can "just run".<ref>{{cite web|url=http://projects.spring.io/spring-boot/|title=Spring Boot|publisher=spring.io}}</ref> It is preconfigured with the Spring team's "opinionated view"{{sfn | Walls | 2016 | loc=§2.4 | p=48}}{{sfn|Deinum|Cosmina|2021|loc=§2 Spring Framework Fundamentals | pp=21-22}} of the best configuration and use of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.{{sfn|Walls|2016|loc=§2.3|pp=37-48}}
 
Key Features:
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* Provide opinionated 'starter' [[Project Object Model]]s (POMs) to simplify your [[Maven (software)|Maven]]/[[Gradle]] configuration{{sfn|Walls|2016|loc=§Preface|p=x}}
* Automatically configure Spring whenever possible{{sfn|Walls|2016|loc=§1.1.2|pp=4-5}}
* Provide production-ready{{sfn|Walls|2016|loc=§foreword|p=vii}} features such as [[software metrics|metrics]],{{sfn|Walls|2016|loc=§7|pp=124-139}} health checks {{sfn|Walls|2016|loc=§7|pp=124-139}} and externalized configuration{{sfn|Walls|2016|loc=§3.1-§3.2.3|pp=49-69}}
* Absolutely no code generation{{sfn|Walls|2016|loc=§1.1.3|p=7}} and no requirement{{sfn|Walls|2016|loc=§Preface|p=x}} for XML configuration.<ref>{{cite web | url=https://aristeksystems.com/blog/what-you-need-know-about-spring-boot/| title=About Spring Boot | accessdate=2020-03-18}}</ref>
* Smooth Integration and supports all Enterprise Integration Patterns.
Line 316 ⟶ 305:
* [[Logging (computing)|logging]]/[[Tracing (software)|tracing]]
* transaction management
* job processing statistics{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-7 Controlling Step Execution|pp=536-541}}
* job restart
 
It provides more advanced technical services and features that enables extremely high-volume{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§16-9 Staging Events Using Spring Batch|pp=714-717}} and high-performance batch jobs{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-7 Controlling Step Execution|pp=536-541}} through optimizations and partitioning{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-7 Controlling Step Execution|pp=536-541}} techniques.
 
Spring Batch executes a series of jobs; a job consists of many steps and each step consists of a "READ-PROCESS-WRITE" task or single operation task (tasklet). A "single" operation task is also known as a tasklet.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-2 Reading and Writing|pp=518-524}} It means doing a single task only, like cleaning up the resources before or after a step is started or completed.
 
The "READ-PROCESS-WRITE" process consists of these steps: "read" data from a resource ([[comma-separated values]] (CSV), XML, or database), "process" it, then "write" it to other resources (CSV, XML, or database). For example, a step may read data from a CSV file,{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-2 Reading and Writing|pp=518-524}} process it, and write it into the database. Spring Batch provides many classes to read/write CSV, XML, and database.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12 Spring Batch|pp=511-512}}
 
The steps can be chained together to run as a job.{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§12-2 Reading and Writing|pp=518-524}}
 
===Integration framework===
{{main article|Spring Integration}}
[[Spring Integration]] is a framework for [[Enterprise application integration]] that provides reusable functions essential to messaging or [[event-driven architecture]]s.
* routers – routes a message to a message channel based on conditions{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§16-8 Conditional Routing with Routers|pp=713-714}}
* transformers – converts/transforms/changes the message payload and creates a new message with transformed payload{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§16-5 Transforming a Message from One Type to Another|pp=704-707}}
* adapters – integrates with other technologies and systems (HTTP, [[AMQP]] (Advanced Message Queuing Protocol),{{sfn | Deinum | RubioLong | LongMak | MakRubio | 2014 | loc=§15-6 Send and Receive AMQP Messages with Spring|pp=686-690}} [[Java Message Service|JMS]] (Java Message Service), [[XMPP]] (Extensible Messaging and Presence Protocol), [[SMTP]] (Simple Mail Transfer Protocol),{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§14-4 Send E-mail with Spring’s E-mail Support|pp=613-620}} [[IMAP]] (Internet Message Access Protocol), [[FTP]] (File Transfer Protocol) as well as [[FTPS]]/[[SSH File Transfer Protocol|SFTP]], file systems, etc.)
* filters – filters a message based on criteria. If the criteria are not met, the message is dropped.{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§9-2 Using Spring in Your Servlets and Filters|p=406}}
* service activators – invoke an operation on a service object. Spring supports the use of the annotation <code>@ServiceActivator</code> to declare the component that requires this functionality.{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§16-2 Integrating Two Systems Using JMS|pp=695-698}}
* management and auditing
* gateways - exposes an interface to the client for the requested services. A messaging middleware is responsible for provisioning this interface. This interface decouples the messaging middleware from the client by hiding the underlying JMS or Spring Integration APIs. Gateways are related to the [[Facade pattern]]. Spring's Integration class, <code>SimpleMessagingGateway</code>, provides essential support for gateways. <code>SimpleMessagingGateway</code> enables the Spring application to specify the channel that sends requests, and the channel that expects to receive responses. The primary focus of <code>SimpleMessagingGateway</code> is to deal with payloads, which spares the client from the intricate details of the transmitted and received messages. <code>SimpleMessagingGateway</code> is used along with channels to enable integration with file systems, JMS, e-mail, or any other systems that require payloads and channels.{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§16-10 Using Gateways|pp=717-722}}
* splitter - Separates a large payload into smaller payloads to support different processing flows. The splitter is achieved in Spring using the splitter component. The splitter component usually forwards the messages to classes with more specialized functionality. Spring supports the <code>@Splitter</code> annotation to declare the component that requires this functionality.{{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§16-7 Forking Integration Control: Splitters and Aggregators|pp=710-713}}
* aggregator - Used for combining many messages into a single result. Loosely speaking, the aggregator is the reverse of the splitter. The aggregator publishes a single message for all components downstream. Spring supports the <code>@Aggregator</code> annotation to declare the component that requires this functionality. {{sfn|Deinum|Rubio|Long|Mak|Rubio|2014|loc=§16-7 Forking Integration Control: Splitters and Aggregators|pp=710-713}}
 
Spring Integration supports pipe-and-filter based architectures.
 
===Spring WebSocket===
An essential rule for dealing with data streams effectively is to never block.{{sfn|Deinum|Cosmina|2021|loc=§11 The WebSocket Protocol|pp=422-425}} The WebSocket is a viable solution to this problem.{{sfn|Deinum|Cosmina|2021|loc=§11 The WebSocket Protocol|pp=422-425}} The WebSocket Protocol is a low-level [[transport protocol]] that allows [[Full duplex|full-duplex]] communication channels over a [[TCP connection]]. The WebSocket acts as an alternative to HTTP to enable two-way communication between the client and the server. The WebSocket is especially useful for applications that require frequent and fast exchanges of small data chunks, at a high speed and volume.{{sfn|Deinum|Cosmina|2021|loc=§11 The WebSocket Protocol|pp=422-425}}
 
Spring supports the WebSocket protocol by providing the WebSocket API for the reactive application. The <code>@EnableWebSocket</code> annotation gives Websocket request processing functionality when places in a Spring configuration class. A mandatory interface is the <code>WebSocketConfigurer</code> which grants access to the <code>WebSocketConfigurer</code>. Then, the Websocket URL is mapped to the relevant handlers by implementing the registerWebSocketHandlers(WebSocketHandlerRegistry) method .{{sfn|Deinum|Cosmina|2021|loc=§11 The WebSocket Protocol|pp=425-432}}
 
===Spring WebFlux===
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Although applications using Spring WebFlux technology is usually less readable than their MVC counterparts, they are more resilient, and simpler to extend.{{sfn|Deinum|Cosmina|2021|loc=§11 Securing Spring WebFlux Applications|p=421}} Spring WebFlux reduces the need to deal with the complications associated with synchronizing thread access.{{sfn|Deinum|Cosmina|2021|loc=§11 Securing Spring WebFlux Applications|p=421}}
 
Spring WebFlux supports [[server-sent events]] (SSE), which is a server push technology that allows the client to get automatic updates from a server through an HTTP connection. This communication is unidirectional, and shares many similarities with the publish/subscribe model found in JMS.{{sfn|Deinum|Cosmina|2021|loc=§11 The WebSocket Protocol|pp=422-425}}
 
==Relationship with Jakarta Enterprise Beans (EJB)==
Line 365 ⟶ 354:
==Spring4Shell vulnerability==
{{See also | Log4Shell}}
A [[remote code execution]] vulnerability affecting certain versions of Spring Framework was published in April 2022 under {{CVE|2022-22965}}. It was given the name ''Spring4Shell'' in reference to the recent [[Log4Shell]] vulnerability, both having similar proofs-of-concept in which attackers could gain shell access on vulnerable machines., gain shell access<ref>{{Cite web |url=https://www.kaspersky.com/blog/spring4shell-critical-vulnerability-in-spring-java-framework/44034/ |title=Spring4Shell: critical vulnerability in Spring - Kaspersky official blog }}</ref> or even full control.<ref>{{cite news |last1=Chirgwin |first1=Richard |title=VMware sprung by Spring4shell vulnerability |url=https://itnews.com.au/news/vmware-sprung-by-spring4shell-vulnerability-578267|archive-url=https://web.archive.org/web/20240213052709/https://www.itnews.com.au/news/vmware-sprung-by-spring4shell-vulnerability-578267 |archive-date=13 February 2024 |access-date=13 February 2024 |publisher=itnews.com.au |date=4 April 2022}}</ref>
 
==See also==
Line 383 ⟶ 372:
* {{cite book | last=Cosmina | first=Iuliana | last2=Harrop | first2=Rob | last3=Schaefer | first3=Chris | last4=Ho | first4=Clarence | title=Pro Spring 5 | publisher=Apress | publication-place=Berkeley, CA | year=2017 | isbn=978-1-4842-2807-4 | doi=10.1007/978-1-4842-2808-1}}
* {{cite book | last=Deinum | first=Marten | last2=Cosmina | first2=Iuliana | title=Pro Spring MVC with WebFlux | publisher=Apress | publication-place=Berkeley, CA | year=2021 | isbn=978-1-4842-5665-7 | doi=10.1007/978-1-4842-5666-4}}
* {{cite book | last=Deinum | first=Marten | last2=Long | first2=Josh | last3=Mak | first3=Gary | last4=Rubio | first4=Daniel | title=Spring Recipes | publisher=Apress | publication-place=Berkeley, CA | year=2014 | isbn=978-1-4302-5908-4 | doi=10.1007/978-1-4302-5909-1}}
*{{cite book
| first1 = Rod
| last1 = Johnson
Line 509 ⟶ 499:
{{Wikibooks|Java Programming|Spring framework}}
* {{Official website|https://spring.io}}
* [https://websparrow.org/category/spring Spring Tutorials]
 
{{Java (Sun)}}