I want to define in my Spring XML context a bean that has a property of the type List of classes: i.e. List<Class<?>> classes
How do I send that bean a number of classes, say java.lang.String and java.lang.Integer?
The list needs not be reusable, i.e. I will not refer to it in another bean.
With Spring, the simplest possibility usually works.....
<property name="classes">
<list>
<value>java.lang.String</value>
<value>java.lang.Integer</value>
</list>
</property>
<property name="classes">
<list>
<bean class="java.lang.Class" factory-method="forName">
<constructor-arg value="java.lang.String"/>
</bean>
</list>
</property>
Something like that...
Related
I need a bean like this
<bean id="studentWithSchool" class="com.model.Student" scope="prototype">
<property name="school">
<bean class="com.model.School" scope="prototype"/>
</property>
</bean>
This is OK.
My problem is I have the student returning from a method from a different bean.
I usually load the bean like this when is a property.
<property name='beanProperty' value='#{anotherBean.getBeanProperty()}'/>
But in this case I need the new bean itself being set from the other bean method (School object is returned from another bean method).
This is what I try, and of course this is wrong:
<bean id="studentWithSchool" class="com.model.Student" scope="prototype" value='#{anotherBean.getBeanProperty()}'>
<property name="school">
<bean class="com.model.School" scope="prototype"/>
</property>
</bean>
Is there any workaround?
If I understand you correctly, the studentWithSchool is created and returned by a method in anotherBean. If that's the case, you can use a factory-method:
<bean id="studentWithSchool" factory-bean="anotherBean" factory-method="getBeanProperty" scope="prototype" />
I believe you are trying to use factory patter with Spring . For that you can use factory bean from spring.
<bean id="studentWithSchool" factory-bean="anotherBeanStaticFactory" factory- method="createBeanProperty" scope="prototype"
<property name="school">
<bean class="com.model.School" scope="prototype"/>
</property>
For more detail you can use below link :-
http://docs.spring.io/spring-framework/docs/2.5.6/api/org/springframework/beans/factory/BeanFactory.html
Inside a web application, I'm using dozer mapper (5.3.2) to perform some object to object mappings.
DozerBeanMapper is instantiated using spring bean definition. Mapping file is provided as property in the spring context xml.
<bean id="idmToBoMPersonMapper" class="org.dozer.DozerBeanMapper" lazy-init="false" scope="singleton" >
<property name="mappingFiles" value="config/IiIdmToBoMPersonMapping.xml"/>
</bean>
Mapping is working, but according to logs, instance of DozerBeanMapper is created every time the code uses the mapper.
INFO DozerBeanMapper:166 - Initializing a new instance of dozer bean mapper.
This is concerns me, I'd expect the mapper to be created once and only once.
I have tried to explicitly use scope="singleton" in the spring bean configuration, but that is not helping either.
Any suggestions for me to try?
I would be better to use the Spring integration with Dozer instead, namely the DozerBeanMapperFactoryBean, see here the documentation for further details:
<bean class="org.dozer.spring.DozerBeanMapperFactoryBean">
<property name="mappingFiles"
value="classpath*:/*mapping.xml"/>
<property name="customConverters">
<list>
<bean class=
"org.dozer.converters.CustomConverter"/>
</list>
</property>
<property name="eventListeners">
<list>
<bean class="org.dozer.listeners.EventListener"/>
</list>
</property>
<property name="factories">
<map>
<entry key="id" value-ref="bean-factory-ref"/>
</map>
</property>
</bean>
How can I define a Spring bean in an xml config file matching this attribute ?
private List<String[]> durations;
I've different things, but none of them seems to work - I'm getting exception from the parser.
Thank you !
You could try a <list> in <list> in the spring application context. A <list> is converted by spring to either a real java.util.List or an array.
<property name="durations">
<list>
<list>
<value>abc</value>
<value>def</value>
</list>
<list>
<value>abc2</value>
<value>def2</value>
</list>
</list>
</property>
Try this:
<bean name="test" class="Test">
<property name="values" value="hugo,emil"/>
</bean>
Spring should carryout the conversion for you if you seperate the values with comma's.
values is a String[] array
Try without generic type : private List durations;
Bean A depends on another Bean B. (Bean B is a property of Bean A).
I want Bean B sometime have objects and sometimes be null.
The simple answer is Yes. In terms of Spring 2.x XML (and this will work in 3.x):
<bean id="A" class="my.bean.A">
<property name="property_B">
<ref local="B"/>
</property>
</bean>
<bean id="B" class="my.bean.B"/>
You can build on this to expand 'B' so that it has its own properties:
<bean id="B" class="my.bean.B">
<property name="property_C">
<ref local="C"/>
</property>
</bean>
You can make B null with respect to A by changing you XML so that B is not injected into A
<bean id="A" class="my.bean.A"/>
Short question: If I have class that impelemnts FactoryBean interface, how can I get from FactoryBean object itself instead of FactoryBean.getObject()?
Long question: I have to use 3-rd party Spring based library which is hardly use FactoryBean interface. Right now I always must configure 2 beans:
<!-- Case 1-->
<bean id="XYZ" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2">
<property name="itemReader" ref="aName"/>
</bean>
</property>
</bean>
<bean id="aName" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.ABC"/>
</property>
</bean>
<!-- Case 2-->
<bean id="XYZ2" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2">
<property name="itemReader" ref="aName2"/>
</bean>
</property>
</bean>
<bean id="aName2" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.QWE"/>
</property>
</bean>
Actyually defintion of a bean with name "XYZ" (compare with "XYZ2") never will be changed, but because of factory nature I must copy the code for each configuration.
Definition of a bean with name "aName" always will be new (i.e. each configuration will have own objectContext value).
I would like to simplify the configuration have a single factory bean (remove "XYZ2" and rid of link to "aName"):
<bean id="XYZ" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2"/>
</property>
</bean>
<bean id="aName" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.ABC"/>
</property>
</bean>
<bean id="aName2" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.QWE"/>
</property>
</bean>
Unfortunately, it's not as simple as I expect. I suppose to glue factory (i.e. XYZ bean from the example) with necessary objects (i.e. "aName", "aName2") at runtime.
The approach doesn't work because when I ask Spring for FactoryBean object it returns to me FactoryBean.getObject() which impossible to instanciate at that time because of missing itemReader value.
I hope that SpringSource foresee my case I can somehome "hook" FactoryBean.getObject() call to provide all necessary properties at runtime.
Another complexity that disturb me a bit it's chains of Factories (Factory1 get an object from Factory2 that I have to "hook" at runtime).
Any ideas will be appreciated.
It's the & (ampersand), not the At-symbol, see Spring Framework documentation: Customizing instantiation logic using FactoryBeans
<property name="factoryBean" ref="&theFactoryBean" />
You can get the factory bean itself using the & syntax in the spring config:
<property name="factoryBean" ref="&theFactoryBean" />
as opposed to:
<property name="createdBean" ref="theFactoryBean" />