Introduction A first example
35. Dynamic language support
35.1 Introduction
Spring 2.0 introduces comprehensive support for using classes and objects that have been defined using a dynamic language such as JRuby with Spring. This support allows you to write any number of classes in a supported dynamic language, and have the Spring container transparently instantiate, configure and dependency inject the resulting objects. The dynamic languages currently supported are: • JRuby 1.5+ • Groovy 1.8+ • BeanShell 2.0 Why only these languages? The supported languages were chosen because a the languages have a lot of traction in the Java enterprise community, b no requests were made for other languages at the time that this support was added, and c the Spring developers were most familiar with them. Fully working examples of where this dynamic language support can be immediately useful are described in Section 35.4, “Scenarios”.35.2 A first example
This bulk of this chapter is concerned with describing the dynamic language support in detail. Before diving into all of the ins and outs of the dynamic language support, let’s look at a quick example of a bean defined in a dynamic language. The dynamic language for this first bean is Groovy the basis of this example was taken from the Spring test suite, so if you want to see equivalent examples in any of the other supported languages, take a look at the source code. Find below the Messenger interface that the Groovy bean is going to be implementing, and note that this interface is defined in plain Java. Dependent objects that are injected with a reference to the Messenger won’t know that the underlying implementation is a Groovy script. package org.springframework.scripting; public interface Messenger { String getMessage; } Here is the definition of a class that has a dependency on the Messenger interface. 4.3.9.RELEASE Spring Framework 771 package org.springframework.scripting; public class DefaultBookingService implements BookingService { private Messenger messenger; public void setMessengerMessenger messenger { this .messenger = messenger; } public void processBooking { use the injected Messenger object... } } Here is an implementation of the Messenger interface in Groovy. from the file Messenger.groovy package org.springframework.scripting.groovy; import the Messenger interface written in Java that is to be implemented import org.springframework.scripting.Messenger define the implementation in Groovy class GroovyMessenger implements Messenger { String message } Finally, here are the bean definitions that will effect the injection of the Groovy-defined Messenger implementation into an instance of the DefaultBookingService class. Note To use the custom dynamic language tags to define dynamic-language-backed beans, you need to have the XML Schema preamble at the top of your Spring XML configuration file. You also need to be using a Spring ApplicationContext implementation as your IoC container. Using the dynamic-language-backed beans with a plain BeanFactory implementation is supported, but you have to manage the plumbing of the Spring internals to do so. For more information on schema-based configuration, see Chapter 41, XML Schema-based configuration. 4.3.9.RELEASE Spring Framework 772 ?xml version=1.0 encoding=UTF-8? beans xmlns = http:www.springframework.orgschemabeans xmlns:xsi = http:www.w3.org2001XMLSchema- instance xmlns:lang = http:www.springframework.orgschemalang xsi:schemaLocation = http:www.springframework.orgschemabeans http:www.springframework.orgschemabeansspring- beans.xsd http:www.springframework.orgschemalang http:www.springframework.orgschemalangspring- lang.xsd -- this is the bean definition for the Groovy-backed Messenger implementation -- lang:groovy id = messenger script-source = classpath:Messenger.groovy lang:property name = message value = I Can Do The Frug lang:groovy -- an otherwise normal bean that will be injected by the Groovy-backed Messenger -- bean id = bookingService class =x.y.DefaultBookingService property
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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