Spring Annotations - I am getting some documents regarding Annotations but, they are explaining each annotation and how to use it.
but i want, know how can achieve same annotations behavior with bean configuration.
ex:
Annotation Bean config
#Required ?
Can you help.................
I don't really understand your question, but here are some links from the Spring Reference that seem relevant:
3.9. Annotation-based container configuration
3.11. Java-based container configuration
On second thought (and after editing your question's source) I seem to understand. I think you want an XML alternative to the #Required annotation.
Quote from the #Required section:
The container throws an exception if the affected bean property has not been populated; this allows for eager and explicit failure, avoiding NullPointerExceptions or the like later on.
I'm not sure such a thing exists in XML, I think the only way to get that behavior is through explicit wiring.
<bean class"foo.bar.Service.class">
<!-- This will fail if no bean named subService is available -->
<property name="subService" ref="subService" />
</bean>
Related
so I am working on a school project and I am trying to build a JSON Rest Webservice application. I am using Spring 4 and Hibernate 4 with Jackson 2.
I have a lot of hard times with this app, but now I have a problem I cannot overgo. I am using Cloudbees as my cloud service provider and from time to time (which is important to state, because it sometimes work and sometimes not!) I get a HTTP 500 error :/.
The best part is - I never had it locally.
It goes more or less like this:
HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalStateException: The mapped controller method class 'pl.lodz.pp.controllers.crud.impl.UserController' is not an instance of the actual controller bean instance 'com.sun.proxy.$Proxy47'. If the controller requires proxying (e.g. due to #Transactional), please use class-based proxying.
And I am so confused. I never get this locally and usually if I restart the application on cloud (one or more time) it will work for some time again.
I had made some errors, like
#Autowire
private ClassType variable
instead of
#Autowire
private ClassInterface variable
but I fixed them all. I am NOT USING #Transactional annotation anymore. At least not in my class. Maybe the GenericDao have it somewhere (https://code.google.com/p/hibernate-generic-dao/) but I never had this problem before.
Transaction management:
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
Please, find the full code here:
https://github.com/atais/PP-JSON
Bottom line
I am not using #Transactional and I inject everything with the Interface type. So what am I possibly doing wrong? And what's the best - it works sometimes, but sometimes I get this error :/
The only thing you need to do is to add
#EnableAspectJAutoProxy(proxyTargetClass = true)
to your Spring Configuration.
In many cases the framework applies for your classes some proxying mechanisms: TX, Cache, Async etc. - depends on annotations, which you are using on your classes or its methods.
So it is good practice to introduce for those classes interfaces and use exactly that contract, not classes.
I understand that it looks like overhead for all #Service classes, but introduce interfaces at least for those classes which use some AOP aspects
I got the same exception when i implemented a interface (controller extends x implements interface) in my controller. Removing the interface solved the problem. I suspect implementing a specific interface is not supported for controllers.
I have validator class which uses
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="/WEB-INF/messages" />
</bean>
Besides validator which does more complex validation I also use JSR303 like
#NotNull(message="null value is not allowed")
protected String postCode;
I want for JSR to use same file source messages.
#NotNull(message=<SOMEHOW GO TO MY messages_en_US.properties AND EXTRACT SOMETHING LIKE : user.poscode.null>)
Thanks!
By default JSR303 validator looks for a file called ValidationMessages.properties, which is bundled with the implementation you use.
If you want to add your own constraint validation messages you have to provide your own ValidationMessages.properties, and add to it the message.
You can look at Message interpolation, Hibernate validator docs.
But what I've just describe its Java EE standard behaviour I don't know if Spring behaves in the same way
I resolved the situation with help of another more focused question of mine on simillar topic. Anyone interested : javax.validation how to target different locale?
Please be aware however that there will be a need in two sets of files including resourcebundle and properties.
Is there any XML equivalent of #Configurable annotation?
For example for the bean:
<bean class="org.obliquid.sherd.domain.SalesDocument" scope ="prototype">
<property name="docType" ref="documentTypeProto"/>
</bean>
How can I tell that SalesDocument should be #Configurable?
No - the purpose of #Configurable to inject properties into objects that are not Spring beans. In your example SalesDocument is already a Spring bean, and docType will be injected.
There's no way to simply do this out of the box that I'm aware of.
One approach to achieve what you want is to look at using Spring AspectJ based AOP extensions. It'll be a lot of work, but if you know that your DAOs need limited configuration (probably the just the EntityManager?) it might be doable.
Look at the spring reference docs for details.
I am using Spring3 with xml based configuration.
The problem is when the IOC container starts it loads/caches all the properties/fields defined in com.dao.MyDAOFactory class. I want to tell spring that only load/cache specific properties/fields.
The bean declaration is given below
<bean id="daoFactory" class="com.dao.MyDAOFactory" ></bean>
Can any one help me ?
You can use the lazy-init attribute to defer the loading of your beans, but eventually all of them will be loaded.
Also keep this in mind that if a non-lazy singleton bean depends on one or more lazy beans, the lazy beans will be loaded at startup.
To be exact, how can I get the value of the <display-name> tag under the <web-app> tag stored in an application's web.xml in a Spring application context configuration XML file.
Ideally I would like something like the following...
<bean><property value="${servletContext.servletContextName}/></bean>
It seem like ServletContext.getServletContextName() does what I want but I can't seem to figure out how to get a handle on that in the Spring application context file.
Ok, the answer is trivial in Spring 3.0.x. Per the documentation for ServletContextFactory
Deprecated. as of Spring 3.0, since "servletContext" is now available as a default bean in every WebApplicationContext
So I decided to try the following and it worked!
<bean><property value="#{servletContext.servletContextName}/></bean>
Since servletContext object is implicitly defined we can access it via Spring EL using the #{} syntax.
I don't think you can do this via the XML config.
You can autowire a bean to receive the ServletContext object (or implement ServletContextAware), and fetch it from that programmatically, but I don't think the XML expressions have any visibility of it.
Maybe try the Expression Language?
<bean>
<property value="#{T(javax.servlet.ServletContext).getServletContextName()}"/>
</bean>
I suspect that would print null if it works though, since there is no context yet.