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Introduction to Spring Framework | PPTX
Introduction to
Spring Framework
August 2014
Serhat CAN
can.srht@gmail.com
Content
• What is Spring Framework?
• Key features of Spring Framework
• Dependency Injection and Inversion of Control
• Aspect Oriented Programming
• Spring Modules
• Advantages of using Spring Framework
2
What is Spring Framework?
• Spring is the most popular application development framework for
enterprise Java.
• Open source Java platform since 2003.
• Spring supports all major application servers and JEE standards.
• Spring handles the infrastructure so you can focus on your
application.
3
• The technology that actually defines Spring (Heart of Spring).
• Dependency Injection helps us to keep our classes as indepedent as
possible.
• Increase reuse by applying low coupling
• Easy testing
• More understandable
Dependency Injection
Introduction to Concept
4
Dependency Injection
Introduction to Concept
“Dependency injection is a pattern where the container passes objects by name to
other objects, via either constructors, properties, or factory methods.”
5
An injection is the passing of a dependency (a service) to a dependent object (a client).
Passing the service to the client, rather than allowing a client to build or find the service, is
the fundamental requirement of the pattern.
Dependency Injection
Relationship Between DI and Inversion of Control
The Inversion of Control (IoC) is a general concept, and it can be expressed in many
different ways and dependency Injection is merely one concrete example of
Inversion of Control.
6
In software engineering, inversion of control (IoC) describes a design in which custom-
written portions of a computer program receive the flow of control from a generic,
reusable library.
Dependency Injection
IoC Container
• The Spring container (IoC Container) is at the core of the Spring
Framework.
• The container will create the objects, wire them together, configure
them, and manage their complete lifecycle from creation till
destruction.
7
• The container gets its instructions on
what objects to instantiate, configure,
and assemble by reading configuration
metadata provided.
• The configuration metadata can be
represented either by;
• XML,
• Java annotations,
• Java code.
Dependency Injection
IoC Container
8
Dependency Injection
Code Example
9
To instantiate the above classes, one way is to do the usual new operator like new Foo() or new Bar() OR we can use
the Spring dependency injection to instantiate these classes and set the properties accordingly.
Dependency Injection
Code Example
10
Foo f = new Foo("Cleopatra");
Bar b = new Bar("Arthur",26);
b.setFoo(f);
Dependency Injection
Code Example
11
Spring's ClassPathXmlApplicationContext is the commonly used object that
hold the information of all the beans that it instantiates.
Dependency Injection
Bean Scopes
12
Scope Description
Singleton (Default) Scopes a single bean definition to a single object instance per Spring IoC container.
Prototype Scopes a single bean definition to any number of object instances.
Aspect Oriented Programming (AOP)
Introduction to Concept
• AOP entails breaking down program logic into distinct parts called concerns.
• The functions that span multiple points of an application are called cross-cutting
concerns and these cross-cutting concerns are conceptually separate from the
application's business logic.
• AOP is like triggers in programming languages
such as Perl, .NET, Java and others.
Examples of cross-cutting concerns:
• Logging
• Security
• Transaction
• Caching
13
Aspect Oriented Programming (AOP)
Spring AOP
• Spring AOP module provides interceptors to intercept an application, for
example, when a method is executed, you can add extra functionality before or
after the method execution.
• Spring AOP's approach to AOP differs from that of most other AOP frameworks.
The aim is to provide a close integration between AOP implementation and
Spring IoC, not to provide the most complete AOP implementation.
• Spring Framework's AOP functionality is normally used in conjunction with the
Spring IoC container. Aspects are configured using normal bean definition syntax.
14
Aspect Oriented Programming (AOP)
Code Example
15
Aspect Oriented Programming (AOP)
Code Example
16
Pointcut (AspectJ Pointcut
Expression Language)
Join Point
Advice
• @Before – Run before the method execution
• @After – Run after the method returned a
result
• @AfterReturning – Run after the method
returned a result, intercept the returned result
as well.
• @Around – Run around the method execution,
combine all three advices above.
• @AfterThrowing – Run after the method
throws an exception
Aspect Oriented Programming (AOP)
Code Example
17
Spring Modules
18
Overview of the Spring Framework
• The Spring Framework consists of
features organized into about 20
modules.
• These modules are grouped into
Core Container, Data
Access/Integration, Web, AOP
(Aspect Oriented Programming),
Instrumentation, and Test.
Spring Modules
• The building blocks described
previously make Spring a logical choice
in many scenarios, from applets to full-
fledged enterprise applications that
use Spring's transaction management
functionality and web framework
integration.
19
Typical full-fledged Spring web application
Spring Modules
Spring Projects
• Spring XD
• Spring Data
• Spring Integration
• Spring Batch
• Spring Security
• Spring Cloud
• Spring AMQP
• Spring Grails
• Spring Mobile
• Spring Social
• Spring for Android
• Spring Web Flow
• Spring LDAP
• Spring Groovy
• Spring Hateoas
• Spring Security OAuth
20
Advantages of Using Spring Framework
• Open source
• Lightweight and fast
• Moduler structure
• Low coupling thanks to Dependency Injection
• Resuable software
• AOP support
• Stable and lots of resources
• Projects that make our life easier like Spring Security
21
Introduction to
Spring Framework - Part 2
Content
• Spring MVC
• Spring RESTful Services
• Spring Security
• Spring Test
23
Spring MVC
• The Spring web MVC framework provides
model-view-controller architecture and
ready components that can be used to
develop flexible and loosely coupled web
applications.
• The MVC pattern results in separating the
different aspects of the application (input
logic, business logic, and UI logic), while
providing a loose coupling between these
elements.
24
Spring MVC
MVC Bean Scopes
25
Scope Description
Request Scopes a single bean definition to the lifecycle of a single HTTP request; that is, each HTTP request has its
own instance of a bean created off the back of a single bean definition. Only valid in the context of a web-
aware Spring ApplicationContext.
Session Scopes a single bean definition to the lifecycle of an HTTP Session. Only valid in the context of a web-
aware Spring ApplicationContext.
Global Session Scopes a single bean definition to the lifecycle of a global HTTP Session. Typically only valid when used in a
portlet context. Only valid in the context of a web-aware SpringApplicationContext.
Application Scopes a single bean definition to the lifecycle of a ServletContext. Only valid in the context of a web-
aware Spring ApplicationContext.
Spring MVC
The DispatcherServlet
• The Spring Web model-view-controller (MVC) framework is designed
around a DispatcherServlet that handles all the HTTP requests and
responses.
26
Spring MVC
Web.xml
• You need to map requests that you want the DispatcherServlet to handle, by using a URL mapping
in the web.xml file.
27
<?xml version="1.0" encoding="UTF-8"?>
<web-app>
<display-name>Example</display-name>
<context:component-scan base-package="com.proj.web" />
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
/WEB-INF/context/example-general-context.xml
</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.
ContextLoaderListener
</listener-class>
</listener>
<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/example-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
Spring MVC
Servlet.xml
• Now, let us check the required configuration for example-servlet.xml file, placed in your web
application's WebContent/WEB-INF directory:
28
<context:component-scan base-package="com.proj.web.controller" />
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/view/" />
<property name="suffix" value=".jsp" />
</bean>
<mvc:annotation-driven />
</beans>
Spring MVC
Controller & View
• HomeController.java:
29
@Controller
public class HomeController {
@RequestMapping(value = { "/", "/home" },
method = RequestMethod.GET)
public String showHomePage(ModelMap model) {
model.addAttribute("message", "Hello
Spring MVC Framework!");
return "home";
}
}
<html>
<head>
<title>Here is home page</title>
</head>
<body>
<h2>${message}</h2>
</body>
</html>
• Home.jsp
Spring RESTful Services
30
• REST does not require the client to know anything about the structure of the API.
Rather, the server needs to provide whatever information the client needs to
interact with the service.
Spring RESTful Services
• Spring's annotation-based MVC framework serves as the basis for creating
RESTful Web Services.
• RESTful services use URIs to name resources. To facilitate accessing the
information contained in a URI, its structure follows conventions so that it can
easily be described in a parameterized form.
31
Spring RESTful Services
• Spring uses the @RequestMapping method annotation to define the URI Template for the
request. The @PathVariable annotation is used to extract the value of the template variables
and assign their value to a method variable.
• When a request comes in for /users/serhat, the value ‘serhat' is bound to the method
parameter String userId.
32
Spring RESTful Services
• A RESTful architecture may expose multiple representations of a resource. There are two
strategies for a client to inform the server of the representation it is interested in receiving.
• The first strategy is to use a distinct URI for each resource. This is typically done by using a
different file extension in the URI.
• For example the URI http://www.example.com/users/serhat.pdf requests a PDF representation of the user serhat
while http://www.example.com/users/serhat.xml requests an XML representation.
• The second strategy is for the client to use the same URI to locate the resource but set
the Accept HTTP request header to list the media types that it understands.
• For example, a HTTP request for http://www.example.com/users/serhat with an Accept header set
to application/pdf requests a PDF representation of the user serhat
while http://www.example.com/users/serhat with an Accept header set to text/xml requests an XML
representation. This strategy is known as content negotiation.
33
Spring RESTful Services
34
Do not forget to implement serializable in your entity
Spring RESTful Services
• This code uses Spring 4’s new @RestController annotation, which marks the class as a controller where every
method returns a domain object instead of a view. It’s shorthand for @Controller and @ResponseBody rolled
together.
• The Greeting object must be converted to JSON. Thanks to Spring’s HTTP message converter support, you don’t
need to do this conversion manually.
35
Spring Security
Spring Security is a framework that focuses on providing both
authentication and authorization to Java applications.
Features:
• Comprehensive and extensible support for both Authentication and Authorization
• Protection against attacks like session fixation, clickjacking, cross site request forgery, etc
• Servlet API integration
• Optional integration with Spring Web MVC
• Much more...
36
Spring Security
Authentication & Authorization
37
Spring Security
Authentication & Authorization
38
Spring Security
Authentication & Authorization
39
Lastly, forcing application to use secure channel
(https) is easy to implement in Spring Security.
Lastly, forcing application to use secure channel
(https) is easy to implement in Spring Security.
Spring Security
Authentication & Authorization
40
Spring special naming for
Spring supported Authentication
Spring Security
Authentication & Authorization
• The authorize & authentication tag
41
Spring Security
Authentication & Authorization
• You can access the Authentication object in your MVC controller (by calling
SecurityContextHolder.getContext().getAuthentication()) and add the data directly to
your model for rendering by the view.
42
Spring Security
Authentication & Authorization
43
• Authorization with annotations in RESTful Web Service
Spring Test
Spring Test Framework supports;
• Unit testing with mock objects
• Easy unit testing for Controllers
• IoC container to create dependencies for Integration Testing
• Transaction management for Integration Testing
• Third party frameworks like JUnit, TestNG, Mockito
44
Spring Test
Unit Testing
45
Spring Test
Unit Testing
46
Spring Test
Unit Testing
47
Spring Test
Integration Testing
48
Spring Test
Integration Testing
49
Spring Test
Integration Testing
50
References
• http://docs.spring.io/spring/docs/current/spring-framework-reference/html/
• http://projects.spring.io/spring-security/
• http://www.mkyong.com/tutorials/spring-mvc-tutorials/
• http://www.mkyong.com/tutorials/spring-security-tutorials/
• http://www.tutorialspoint.com/spring/
• http://www.mkyong.com/tutorials/spring-tutorials/
• http://www.slideshare.net/rstoya05/testing-web-apps-with-spring-framework-32
• http://www.petrikainulainen.net/programming/spring-framework/integration-
testing-of-spring-mvc-applications-security/
51
Thank you for listening...

Introduction to Spring Framework

  • 1.
    Introduction to Spring Framework August2014 Serhat CAN can.srht@gmail.com
  • 2.
    Content • What isSpring Framework? • Key features of Spring Framework • Dependency Injection and Inversion of Control • Aspect Oriented Programming • Spring Modules • Advantages of using Spring Framework 2
  • 3.
    What is SpringFramework? • Spring is the most popular application development framework for enterprise Java. • Open source Java platform since 2003. • Spring supports all major application servers and JEE standards. • Spring handles the infrastructure so you can focus on your application. 3
  • 4.
    • The technologythat actually defines Spring (Heart of Spring). • Dependency Injection helps us to keep our classes as indepedent as possible. • Increase reuse by applying low coupling • Easy testing • More understandable Dependency Injection Introduction to Concept 4
  • 5.
    Dependency Injection Introduction toConcept “Dependency injection is a pattern where the container passes objects by name to other objects, via either constructors, properties, or factory methods.” 5 An injection is the passing of a dependency (a service) to a dependent object (a client). Passing the service to the client, rather than allowing a client to build or find the service, is the fundamental requirement of the pattern.
  • 6.
    Dependency Injection Relationship BetweenDI and Inversion of Control The Inversion of Control (IoC) is a general concept, and it can be expressed in many different ways and dependency Injection is merely one concrete example of Inversion of Control. 6 In software engineering, inversion of control (IoC) describes a design in which custom- written portions of a computer program receive the flow of control from a generic, reusable library.
  • 7.
    Dependency Injection IoC Container •The Spring container (IoC Container) is at the core of the Spring Framework. • The container will create the objects, wire them together, configure them, and manage their complete lifecycle from creation till destruction. 7
  • 8.
    • The containergets its instructions on what objects to instantiate, configure, and assemble by reading configuration metadata provided. • The configuration metadata can be represented either by; • XML, • Java annotations, • Java code. Dependency Injection IoC Container 8
  • 9.
    Dependency Injection Code Example 9 Toinstantiate the above classes, one way is to do the usual new operator like new Foo() or new Bar() OR we can use the Spring dependency injection to instantiate these classes and set the properties accordingly.
  • 10.
    Dependency Injection Code Example 10 Foof = new Foo("Cleopatra"); Bar b = new Bar("Arthur",26); b.setFoo(f);
  • 11.
    Dependency Injection Code Example 11 Spring'sClassPathXmlApplicationContext is the commonly used object that hold the information of all the beans that it instantiates.
  • 12.
    Dependency Injection Bean Scopes 12 ScopeDescription Singleton (Default) Scopes a single bean definition to a single object instance per Spring IoC container. Prototype Scopes a single bean definition to any number of object instances.
  • 13.
    Aspect Oriented Programming(AOP) Introduction to Concept • AOP entails breaking down program logic into distinct parts called concerns. • The functions that span multiple points of an application are called cross-cutting concerns and these cross-cutting concerns are conceptually separate from the application's business logic. • AOP is like triggers in programming languages such as Perl, .NET, Java and others. Examples of cross-cutting concerns: • Logging • Security • Transaction • Caching 13
  • 14.
    Aspect Oriented Programming(AOP) Spring AOP • Spring AOP module provides interceptors to intercept an application, for example, when a method is executed, you can add extra functionality before or after the method execution. • Spring AOP's approach to AOP differs from that of most other AOP frameworks. The aim is to provide a close integration between AOP implementation and Spring IoC, not to provide the most complete AOP implementation. • Spring Framework's AOP functionality is normally used in conjunction with the Spring IoC container. Aspects are configured using normal bean definition syntax. 14
  • 15.
    Aspect Oriented Programming(AOP) Code Example 15
  • 16.
    Aspect Oriented Programming(AOP) Code Example 16 Pointcut (AspectJ Pointcut Expression Language) Join Point Advice • @Before – Run before the method execution • @After – Run after the method returned a result • @AfterReturning – Run after the method returned a result, intercept the returned result as well. • @Around – Run around the method execution, combine all three advices above. • @AfterThrowing – Run after the method throws an exception
  • 17.
    Aspect Oriented Programming(AOP) Code Example 17
  • 18.
    Spring Modules 18 Overview ofthe Spring Framework • The Spring Framework consists of features organized into about 20 modules. • These modules are grouped into Core Container, Data Access/Integration, Web, AOP (Aspect Oriented Programming), Instrumentation, and Test.
  • 19.
    Spring Modules • Thebuilding blocks described previously make Spring a logical choice in many scenarios, from applets to full- fledged enterprise applications that use Spring's transaction management functionality and web framework integration. 19 Typical full-fledged Spring web application
  • 20.
    Spring Modules Spring Projects •Spring XD • Spring Data • Spring Integration • Spring Batch • Spring Security • Spring Cloud • Spring AMQP • Spring Grails • Spring Mobile • Spring Social • Spring for Android • Spring Web Flow • Spring LDAP • Spring Groovy • Spring Hateoas • Spring Security OAuth 20
  • 21.
    Advantages of UsingSpring Framework • Open source • Lightweight and fast • Moduler structure • Low coupling thanks to Dependency Injection • Resuable software • AOP support • Stable and lots of resources • Projects that make our life easier like Spring Security 21
  • 22.
  • 23.
    Content • Spring MVC •Spring RESTful Services • Spring Security • Spring Test 23
  • 24.
    Spring MVC • TheSpring web MVC framework provides model-view-controller architecture and ready components that can be used to develop flexible and loosely coupled web applications. • The MVC pattern results in separating the different aspects of the application (input logic, business logic, and UI logic), while providing a loose coupling between these elements. 24
  • 25.
    Spring MVC MVC BeanScopes 25 Scope Description Request Scopes a single bean definition to the lifecycle of a single HTTP request; that is, each HTTP request has its own instance of a bean created off the back of a single bean definition. Only valid in the context of a web- aware Spring ApplicationContext. Session Scopes a single bean definition to the lifecycle of an HTTP Session. Only valid in the context of a web- aware Spring ApplicationContext. Global Session Scopes a single bean definition to the lifecycle of a global HTTP Session. Typically only valid when used in a portlet context. Only valid in the context of a web-aware SpringApplicationContext. Application Scopes a single bean definition to the lifecycle of a ServletContext. Only valid in the context of a web- aware Spring ApplicationContext.
  • 26.
    Spring MVC The DispatcherServlet •The Spring Web model-view-controller (MVC) framework is designed around a DispatcherServlet that handles all the HTTP requests and responses. 26
  • 27.
    Spring MVC Web.xml • Youneed to map requests that you want the DispatcherServlet to handle, by using a URL mapping in the web.xml file. 27 <?xml version="1.0" encoding="UTF-8"?> <web-app> <display-name>Example</display-name> <context:component-scan base-package="com.proj.web" /> <context-param> <param-name>contextConfigLocation</param-name> <param-value> /WEB-INF/context/example-general-context.xml </param-value> </context-param> <listener> <listener-class> org.springframework.web.context. ContextLoaderListener </listener-class> </listener> <servlet> <servlet-name>spring</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/example-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>spring</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
  • 28.
    Spring MVC Servlet.xml • Now,let us check the required configuration for example-servlet.xml file, placed in your web application's WebContent/WEB-INF directory: 28 <context:component-scan base-package="com.proj.web.controller" /> <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/WEB-INF/view/" /> <property name="suffix" value=".jsp" /> </bean> <mvc:annotation-driven /> </beans>
  • 29.
    Spring MVC Controller &View • HomeController.java: 29 @Controller public class HomeController { @RequestMapping(value = { "/", "/home" }, method = RequestMethod.GET) public String showHomePage(ModelMap model) { model.addAttribute("message", "Hello Spring MVC Framework!"); return "home"; } } <html> <head> <title>Here is home page</title> </head> <body> <h2>${message}</h2> </body> </html> • Home.jsp
  • 30.
    Spring RESTful Services 30 •REST does not require the client to know anything about the structure of the API. Rather, the server needs to provide whatever information the client needs to interact with the service.
  • 31.
    Spring RESTful Services •Spring's annotation-based MVC framework serves as the basis for creating RESTful Web Services. • RESTful services use URIs to name resources. To facilitate accessing the information contained in a URI, its structure follows conventions so that it can easily be described in a parameterized form. 31
  • 32.
    Spring RESTful Services •Spring uses the @RequestMapping method annotation to define the URI Template for the request. The @PathVariable annotation is used to extract the value of the template variables and assign their value to a method variable. • When a request comes in for /users/serhat, the value ‘serhat' is bound to the method parameter String userId. 32
  • 33.
    Spring RESTful Services •A RESTful architecture may expose multiple representations of a resource. There are two strategies for a client to inform the server of the representation it is interested in receiving. • The first strategy is to use a distinct URI for each resource. This is typically done by using a different file extension in the URI. • For example the URI http://www.example.com/users/serhat.pdf requests a PDF representation of the user serhat while http://www.example.com/users/serhat.xml requests an XML representation. • The second strategy is for the client to use the same URI to locate the resource but set the Accept HTTP request header to list the media types that it understands. • For example, a HTTP request for http://www.example.com/users/serhat with an Accept header set to application/pdf requests a PDF representation of the user serhat while http://www.example.com/users/serhat with an Accept header set to text/xml requests an XML representation. This strategy is known as content negotiation. 33
  • 34.
    Spring RESTful Services 34 Donot forget to implement serializable in your entity
  • 35.
    Spring RESTful Services •This code uses Spring 4’s new @RestController annotation, which marks the class as a controller where every method returns a domain object instead of a view. It’s shorthand for @Controller and @ResponseBody rolled together. • The Greeting object must be converted to JSON. Thanks to Spring’s HTTP message converter support, you don’t need to do this conversion manually. 35
  • 36.
    Spring Security Spring Securityis a framework that focuses on providing both authentication and authorization to Java applications. Features: • Comprehensive and extensible support for both Authentication and Authorization • Protection against attacks like session fixation, clickjacking, cross site request forgery, etc • Servlet API integration • Optional integration with Spring Web MVC • Much more... 36
  • 37.
  • 38.
  • 39.
    Spring Security Authentication &Authorization 39 Lastly, forcing application to use secure channel (https) is easy to implement in Spring Security. Lastly, forcing application to use secure channel (https) is easy to implement in Spring Security.
  • 40.
    Spring Security Authentication &Authorization 40 Spring special naming for Spring supported Authentication
  • 41.
    Spring Security Authentication &Authorization • The authorize & authentication tag 41
  • 42.
    Spring Security Authentication &Authorization • You can access the Authentication object in your MVC controller (by calling SecurityContextHolder.getContext().getAuthentication()) and add the data directly to your model for rendering by the view. 42
  • 43.
    Spring Security Authentication &Authorization 43 • Authorization with annotations in RESTful Web Service
  • 44.
    Spring Test Spring TestFramework supports; • Unit testing with mock objects • Easy unit testing for Controllers • IoC container to create dependencies for Integration Testing • Transaction management for Integration Testing • Third party frameworks like JUnit, TestNG, Mockito 44
  • 45.
  • 46.
  • 47.
  • 48.
  • 49.
  • 50.
  • 51.
    References • http://docs.spring.io/spring/docs/current/spring-framework-reference/html/ • http://projects.spring.io/spring-security/ •http://www.mkyong.com/tutorials/spring-mvc-tutorials/ • http://www.mkyong.com/tutorials/spring-security-tutorials/ • http://www.tutorialspoint.com/spring/ • http://www.mkyong.com/tutorials/spring-tutorials/ • http://www.slideshare.net/rstoya05/testing-web-apps-with-spring-framework-32 • http://www.petrikainulainen.net/programming/spring-framework/integration- testing-of-spring-mvc-applications-security/ 51
  • 52.
    Thank you forlistening...