org.springframework.batch.core.scope
Class StepScope

java.lang.Object
  org.springframework.batch.core.scope.StepScope

All Implemented Interfaces:

org.springframework.beans.factory.config.BeanFactoryPostProcessor, org.springframework.beans.factory.config.Scope, org.springframework.core.Ordered

public class StepScope
extends java.lang.Object
implements org.springframework.beans.factory.config.Scope, org.springframework.beans.factory.config.BeanFactoryPostProcessor, org.springframework.core.Ordered

Scope for step context. Objects in this scope use the Spring container as an object factory, so there is only one instance of such a bean per executing step. All objects in this scope are <aop:scoped-proxy/> (no need to decorate the bean definitions).

In addition, support is provided for late binding of references accessible from the StepContext using #{..} placeholders. Using this feature, bean properties can be pulled from the step or job execution context and the job parameters. E.g.

 <bean id="..." class="..." scope="step">
        <property name="parent" ref="#{stepExecutionContext[helper]}" />
 </bean>
 
 <bean id="..." class="..." scope="step">
        <property name="name" value="#{stepExecutionContext['input.name']}" />
 </bean>
 
 <bean id="..." class="..." scope="step">
        <property name="name" value="#{jobParameters[input]}" />
 </bean>
 
 <bean id="..." class="..." scope="step">
        <property name="name" value="#{jobExecutionContext['input.stem']}.txt" />
 </bean>
 

The StepContext is referenced using standard bean property paths (as per BeanWrapper). The examples above all show the use of the Map accessors provided as a convenience for step and job attributes.

Since:

2.0

Author:

Dave Syer

Field Summary

static java.lang.String

ID_KEY Context key for clients to use for conversation identifier.

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

StepScope()

Method Summary

java.lang.Object	get(java.lang.String name, org.springframework.beans.factory.ObjectFactory objectFactory)
java.lang.String	getConversationId()
int	getOrder()
void	postProcessBeanFactory(org.springframework.beans.factory.config.ConfigurableListableBeanFactory beanFactory) Register this scope with the enclosing BeanFactory.
void	registerDestructionCallback(java.lang.String name, java.lang.Runnable callback)
java.lang.Object	remove(java.lang.String name)
java.lang.Object	resolveContextualObject(java.lang.String key) If Spring 3.0 is available, this will be used to resolve expressions in step-scoped beans.
void	setName(java.lang.String name) Public setter for the name property.
void	setOrder(int order)
void	setProxyTargetClass(boolean proxyTargetClass) Flag to indicate that proxies should use dynamic subclassing.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ID_KEY

public static final java.lang.String ID_KEY

Context key for clients to use for conversation identifier.

See Also:

Constant Field Values

Constructor Detail

StepScope

public StepScope()

Method Detail

setOrder

public void setOrder(int order)

Parameters:

order - the order value to set priority of callback execution for the BeanFactoryPostProcessor part of this scope bean.

getOrder

public int getOrder()

Specified by:

getOrder in interface org.springframework.core.Ordered

setProxyTargetClass

public void setProxyTargetClass(boolean proxyTargetClass)

Flag to indicate that proxies should use dynamic subclassing. This allows classes with no interface to be proxied. Defaults to false.

Parameters:

proxyTargetClass - set to true to have proxies created using dynamic subclasses

resolveContextualObject

public java.lang.Object resolveContextualObject(java.lang.String key)

If Spring 3.0 is available, this will be used to resolve expressions in step-scoped beans. This method is part of the Scope SPI in Spring 3.0, but should just be ignored by earlier versions of Spring.

get

public java.lang.Object get(java.lang.String name,
                            org.springframework.beans.factory.ObjectFactory objectFactory)

Specified by:

get in interface org.springframework.beans.factory.config.Scope

See Also:

Scope.get(String, ObjectFactory)

getConversationId

public java.lang.String getConversationId()

Specified by:

getConversationId in interface org.springframework.beans.factory.config.Scope

See Also:

Scope.getConversationId()

registerDestructionCallback

public void registerDestructionCallback(java.lang.String name,
                                        java.lang.Runnable callback)

Specified by:

registerDestructionCallback in interface org.springframework.beans.factory.config.Scope

See Also:

Scope.registerDestructionCallback(String, Runnable)

remove

public java.lang.Object remove(java.lang.String name)

Specified by:

remove in interface org.springframework.beans.factory.config.Scope

See Also:

Scope.remove(String)

postProcessBeanFactory

public void postProcessBeanFactory(org.springframework.beans.factory.config.ConfigurableListableBeanFactory beanFactory)
                            throws org.springframework.beans.BeansException

Register this scope with the enclosing BeanFactory.

Specified by:

postProcessBeanFactory in interface org.springframework.beans.factory.config.BeanFactoryPostProcessor

Parameters:

beanFactory - the BeanFactory to register with

Throws:

org.springframework.beans.BeansException - if there is a problem.

See Also:

BeanFactoryPostProcessor.postProcessBeanFactory(ConfigurableListableBeanFactory)

setName

public void setName(java.lang.String name)

Public setter for the name property. This can then be used as a bean definition attribute, e.g. scope="step". Defaults to "step".

Parameters:

name - the name to set for this scope.