Scenarios Dynamic language support
35.4 Scenarios
The possible scenarios where defining Spring managed beans in a scripting language would be beneficial are, of course, many and varied. This section describes two possible use cases for the dynamic language support in Spring. Scripted Spring MVC Controllers One group of classes that may benefit from using dynamic-language-backed beans is that of Spring MVC controllers. In pure Spring MVC applications, the navigational flow through a web application is to a large extent determined by code encapsulated within your Spring MVC controllers. As the navigational flow and other presentation layer logic of a web application needs to be updated to respond to support issues or changing business requirements, it may well be easier to effect any such required changes by editing one or more dynamic language source files and seeing those changes being immediately reflected in the state of a running application. Remember that in the lightweight architectural model espoused by projects such as Spring, you are typically aiming to have a really thin presentation layer, with all the meaty business logic of an application being contained in the domain and service layer classes. Developing Spring MVC controllers as dynamic-language-backed beans allows you to change presentation layer logic by simply editing and saving text files; any changes to such dynamic language source files will depending on the configuration automatically be reflected in the beans that are backed by dynamic language source files. Note In order to effect this automatic pickup of any changes to dynamic-language-backed beans, you will have had to enable the refreshable beans functionality. See the section called “Refreshable beans” for a full treatment of this feature. Find below an example of an org.springframework.web.servlet.mvc.Controller implemented using the Groovy dynamic language. from the file WEB-INFgroovyFortuneController.groovy package org.springframework.showcase.fortune.web import org.springframework.showcase.fortune.service.FortuneService import org.springframework.showcase.fortune.domain.Fortune import org.springframework.web.servlet.ModelAndView import org.springframework.web.servlet.mvc.Controller import javax.servlet.http.HttpServletRequest import javax.servlet.http.HttpServletResponse class FortuneController implements Controller { Property FortuneService fortuneService ModelAndView handleRequestHttpServletRequest request, HttpServletResponse httpServletResponse { return new ModelAndView tell , fortune , this .fortuneService.tellFortune } } lang:groovy id = fortune refresh-check-delay = 3000 script-source = WEB-INFgroovyFortuneController.groovy lang:property name = fortuneService ref = fortuneService lang:groovy 4.3.9.RELEASE Spring Framework 783 Scripted Validators Another area of application development with Spring that may benefit from the flexibility afforded by dynamic-language-backed beans is that of validation. It may be easier to express complex validation logic using a loosely typed dynamic language that may also have support for inline regular expressions as opposed to regular Java. Again, developing validators as dynamic-language-backed beans allows you to change validation logic by simply editing and saving a simple text file; any such changes will depending on the configuration automatically be reflected in the execution of a running application and would not require the restart of an application. Note Please note that in order to effect the automatic pickup of any changes to dynamic-language- backed beans, you will have had to enable the refreshable beans feature. See the section called “Refreshable beans” for a full and detailed treatment of this feature. Find below an example of a Spring org.springframework.validation.Validator implemented using the Groovy dynamic language. See Section 9.2, “Validation using Spring’s Validator interface” for a discussion of the Validator interface. import org.springframework.validation.Validator import org.springframework.validation.Errors import org.springframework.beans.TestBean class TestBeanValidator implements Validator { boolean supportsClass clazz { return TestBean. class .isAssignableFromclazz } void validateObject bean, Errors errors { if bean.name?.trim?.size 0 { return } errors.reject whitespace , Cannot be composed wholly of whitespace. } }35.5 Bits and bobs
Parts
» Dependency Injection and Inversion of Control Framework Modules
» Usage scenarios Introduction to the Spring Framework
» Java EE 6 and 7 Groovy Bean Definition DSL
» Core Container Improvements General Web Improvements
» WebSocket, SockJS, and STOMP Messaging Testing Improvements
» JMS Improvements Caching Improvements
» Web Improvements New Features and Enhancements in Spring Framework 1
» WebSocket Messaging Improvements Testing Improvements
» Core Container Improvements New Features and Enhancements in Spring Framework 4.2
» Data Access Improvements JMS Improvements Web Improvements
» Core Container Improvements Data Access Improvements Caching Improvements
» JMS Improvements Web Improvements WebSocket Messaging Improvements Testing Improvements
» Introduction to the Spring IoC container and beans
» Container overview The IoC container
» Bean overview The IoC container
» Dependencies The IoC container
» y.Baz beans The IoC container
» driverClassName = username = The IoC container
» email = spouse-ref = The IoC container
» y.Bar bean y.Foo constructor-arg y.Foo c:bar-ref baz-ref = y.Foo c:_0-ref _1-ref =
» y.z.MyValueCalculator b.c.ReplacementComputeValue Bean scopes
» y.Foo property Customizing the nature of a bean
» Bean definition inheritance The IoC container
» Container Extension Points The IoC container
» Annotation-based container configuration The IoC container
» Classpath scanning and managed components
» Using JSR 330 Standard Annotations
» Java-based container configuration The IoC container
» Environment abstraction The IoC container
» Registering a LoadTimeWeaver Additional Capabilities of the ApplicationContext
» The BeanFactory The IoC container
» Introduction The Resource interface
» Built-in Resource implementations Resources
» The ResourceLoaderAware interface Resources
» Resources as dependencies Application contexts and Resource paths
» Introduction Validation, Data Binding, and Type Conversion
» Validation using Spring’s Validator interface
» Resolving codes to error messages Bean manipulation and the BeanWrapper
» Spring Type Conversion Validation, Data Binding, and Type Conversion
» Spring Field Formatting Validation, Data Binding, and Type Conversion
» Configuring a global date time format
» Spring Validation Validation, Data Binding, and Type Conversion
» Introduction Feature Overview Spring Expression Language SpEL
» Expression Evaluation using Spring’s Expression Interface
» Expression support for defining bean definitions
» Language Reference Spring Expression Language SpEL
» 3e0 4 .getValueDouble. 4e0 2 .getValueDouble.
» Classes used in the examples
» Introduction Aspect Oriented Programming with Spring
» Schema-based AOP support Aspect Oriented Programming with Spring
» y.service.DefaultFooService y.SimpleProfiler aop:config
» Choosing which AOP declaration style to use
» Mixing aspect types Proxying mechanisms
» Introduction Pointcut API in Spring
» Advisor API in Spring Using the ProxyFactoryBean to create AOP proxies
» Concise proxy definitions Spring AOP APIs
» Creating AOP proxies programmatically with the ProxyFactory Manipulating advised objects
» Using the auto-proxy facility
» Using TargetSources Spring AOP APIs
» Mock Objects Unit Testing support Classes
» Overview Goals of Integration Testing
» JDBC Testing Support Annotations
» Spring TestContext Framework Integration Testing
» loginAction-ref = username = userPreferences-ref = theme =
» PetClinic Example Integration Testing
» Understanding the Spring Framework transaction abstraction
» Synchronizing resources with transactions
» Declarative transaction management Transaction Management
» y.service.DefaultFooService Transaction Management
» y.service.DefaultFooService y.SimpleProfiler y.service.DefaultFooService
» y.SimpleProfiler Transaction Management
» Programmatic transaction management Transaction Management
» Choosing between programmatic and declarative transaction management Transaction bound event
» Application server-specific integration Transaction Management
» Introduction Consistent exception hierarchy
» Annotations used for configuring DAO or Repository classes
» Introduction to Spring Framework JDBC
» Using the JDBC core classes to control basic JDBC processing and error handling
» Controlling database connections Data access with JDBC
» JDBC batch operations Data access with JDBC
» Simplifying JDBC operations with the SimpleJdbc classes
» Modeling JDBC operations as Java objects
» Common problems with parameter and data value handling
» Embedded database support Data access with JDBC
» Initializing a DataSource Data access with JDBC
» Introduction to ORM with Spring
» General ORM integration considerations
» Hibernate Object Relational Mapping ORM Data Access
» JDO Object Relational Mapping ORM Data Access
» Introduction Marshaller and Unmarshaller
» Using Marshaller and Unmarshaller
» XML Schema-based Configuration JAXB
» Castor Marshalling XML using OX Mappers
» XMLBeans JiBX Marshalling XML using OX Mappers
» XStream Marshalling XML using OX Mappers
» Introduction to Spring Web MVC framework
» The DispatcherServlet Web MVC framework
» Handler mappings Web MVC framework
» Resolving views Web MVC framework
» Using flash attributes Web MVC framework
» Building URIs Web MVC framework
» Using locales Web MVC framework
» Using themes Web MVC framework
» Spring’s multipart file upload support
» Handling exceptions Web MVC framework
» Web Security Convention over configuration support
» y.RegistrationController HTTP caching support
» Code-based Servlet container initialization
» Configuring Spring MVC Web MVC framework
» simpleDateFormat = Web MVC framework
» Introduction Thymeleaf Groovy Markup Templates
» Velocity FreeMarker View technologies
» Document views PDFExcel Property
» Feed Views JSON Mapping View
» Introduction Integrating with other web frameworks
» Common configuration Integrating with other web frameworks
» JavaServer Faces 1.2 Apache Struts 2.x
» Introduction Portlet MVC Framework
» The DispatcherPortlet Portlet MVC Framework
» The ViewRendererServlet Controllers Portlet MVC Framework
» Handler mappings Portlet MVC Framework
» Views and resolving them Multipart file upload support
» Handling exceptions Annotation-based controller configuration
» absolute-ordering absolute-ordering WebSocket API
» SockJS Fallback Options WebSocket Support
» STOMP Over WebSocket Messaging Architecture
» Introduction Controller method CORS configuration
» Global CORS configuration Advanced Customization
» Introduction Remoting and web services using Spring
» Using Hessian or Burlap to remotely call services via HTTP
» Exposing services using HTTP invokers
» Web services Remoting and web services using Spring
» JMS Remoting and web services using Spring
» Accessing RESTful services on the Client
» Introduction Accessing EJBs Enterprise JavaBeans EJB integration
» Introduction JMS Java Message Service
» Using Spring JMS JMS Java Message Service
» Sending a Message JMS Java Message Service
» Receiving a message JMS Java Message Service
» Support for JCA Message Endpoints
» Annotation-driven listener endpoints JMS Java Message Service
» JMS namespace support JMS Java Message Service
» Introduction Exporting your beans to JMX
» Controlling the management interface of your beans
» Controlling the ObjectNames for your beans
» Accessing MBeans via Proxies
» Introduction Configuring CCI JCA CCI
» Using Spring’s CCI access support
» Modeling CCI access as operation objects
» Using the JavaMail MimeMessageHelper
» Introduction The Spring TaskExecutor abstraction
» The Spring TaskScheduler abstraction
» Annotation Support for Scheduling and Asynchronous Execution
» The task namespace Task Execution and Scheduling
» Introduction A first example
» y.DefaultBookingService property Defining beans that are backed by dynamic languages
» y.DefaultBookingService property Dynamic language support
» Scenarios Dynamic language support
» Bits and bobs y.DefaultBookingService property
» Introduction Understanding the cache abstraction
» Declarative annotation-based caching Cache Abstraction
» JCache JSR-107 annotations Cache Abstraction
» Declarative XML-based caching y.service.DefaultBookService
» Configuring the cache storage name =
» Classic ORM usage Classic Spring Usage
» JMS Usage Classic Spring Usage
» Concise proxy definitions Classic Spring AOP Usage
» Using the autoproxy facility
» Using TargetSources Classic Spring AOP Usage
» Introduction XML Schema-based configuration
» Introduction Authoring the schema
» Coding a NamespaceHandler Extensible XML authoring
» BeanDefinitionParser Extensible XML authoring
» Registering the handler and the schema
» Using a custom extension in your Spring XML configuration Meatier examples
» Introduction The argument tag The bind tag
» The escapeBody tag The eval tag The hasBindErrors tag
» The htmlEscape tag The message tag
» The nestedPath tag The param tag The theme tag
» The transform tag The url tag
» Introduction The button tag The checkbox tag
» The checkboxes tag The errors tag
» The option tag The options tag
» The password tag The radiobutton tag
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