Scheduled Annotation not working without component scan - java

I am using Spring's task executor to schedule a method at regular interval.
public class ABC{
#Scheduled(fixedDelay=100000)
public void test(){
}
}
It doesn't work with simple bean declaration for the class ABC.
<bean id="abc" class="com.test.ABC" />
If I put component scan then it works fine.
<context:component-scan base-package="com.test"/>
<context:annotation-config/>
What could be the reason?
I think, both should work fine as Component scan is just an alternative for defining individual bean. might be something wrong from my side.
Let me know if my thoughts are not correct.
Thanks,

Related

How to load two ResourceBundles and inject them separately

I am using Spring for loading localized resource bundles into my application. Here is what I have done.
<bean id="systemMessages" class="o.s.c.s.ResourceBundleMessageSource">
<property name="basename" value="locale/system">
</bean>
<bean id="clientMessages" class="o.s.c.s.ResourceBundleMessageSource">
<property name="basename" value="locale/client">
</bean>
I want to load messages based on the locale in my controller, and I tried both these ways below
#Autowired
#Qualifier("clientMessages")
ResourceBundleMessageSource clientMessages;
#Resource(name="systemMessages")
ResourceBundleMessageSource systemMessages;
EDIT
The application is a JAXRS application and the injection is being tried in a Global Exception Mapper. From the comments I now understand that this class would have been created by the JAXRS container and not Spring ( Code below). How to let Spring know that this injection must work?
import javax.ws.rs.WebApplicationException;
//other imports
public class GlobalWebApplicationException extends WebApplicationException{
private String systemMessage;
private String clientMessage;
//Autowire the multiple resourcebundles
public GlobalWebApplicationException (String key, Locale locale) {
// this is where I want to use the injected object fetch the property
}
public doSomething(){
// Business Logic
}
}
But the injection is not happening and I am getting an NPE. How do I achieve this?
When using Spring and having it do auto wiring using annotations the fields cannot be null. The dependencies need to be satisfied on startup of the application. If that doesn't happen there can be 1 of 2 things wrong
You haven't enabled annotation processing
You aren't using a spring managed bean but are creating instances yourself
For the first option add <context:annotation-config /> to your application context, or if you want to do component scanning add <context:component-scan /> the latter already implies annotation processing.
For the second option you need to make your bean a spring managed bean and use that instead of creating new instances yourself.

#Async does not work with task:executor

I'm trying to call a method in Spring-powered bean asynchronously using #Async. I defined an executor in XML:
<task:executor id="emailTasksExecutor" pool-size="1" />
and here is my method:
#Override
#Async("emailTasksExecutor")
public void sendEmail()
{
...
}
And the method does not get called at all when I use qualifier (emailTasksExecutor). However, if I remove it, everything works ok. But in this case the default executor is used and I need to change this behaviour.
I thought the problem is that my class does not implement any interfaces, and something went wrong with proxies. But extracting the interface did not help.
So, the problem was my maven-aspectj-plugin. I found the solution here. All I need to do is to add mode="aspectj" to the task:annotation-driven.

Spring configured mock giving two different instances

Note: I have purposefully removed words from the names of classes and objects, so please excuse the horribly names in my code examples
I've got a test class that sets up my application using some test Spring context files. The application is a wrapper to a web service.
As this is a test, I have mocked the main interface to the web service in question (the ITransporter class). This gives me the ability to set expectations so that I can check that the requests sent to the web service are: in the expected format; have the expected fields complete; etc...
My mock is defined in a file called test-beans-context.xml and is passed into some service beans, as follows:
<bean id="mockTransporter" class="org.easymock.EasyMock" factory-method="createMock" scope="singleton">
<constructor-arg index="0" value="transport.ITransporter" />
</bean>
<bean id="accountService" class="service.AccountService">
<property name="transporter" ref="mockTransporter" />
</bean>
This context file is used in 2 places. (And I fear this is where my problem arises.)
The first being the test class, which is defined as follows:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration( locations={"classpath:test-beans-context.xml"} )
public class AbstractIntegrationTest {
#Autowired
private ITransporter mockTransporter;
//Some tests that perform expectations like the following:
// EasyMock.reset( this.mockTransporter );
// EasyMock.expect( this.mockTransporter.sendRequest( EasyMock.capture(this.requestXmlCapture) ) ).andReturn( responseXml );
}
The second place is in a class that is within the logical trail for getting to sending the request. It loads a separate XML context file /lite-api-context.xml that then imports the test one in my test set up.
public class Factory implements IFactory {
public Factory() {
context = new ClassPathXmlApplicationContext("/lite-api-context.xml");
}
#Override
public IAccountService getAccountService() {
return (IAccountService) context.getBean("accountService");
}
}
And lite-api-context.xml includes this:
<import resource="classpath:/test-beans-context.xml" />
My problem is that in the test class, I'm getting a different instance of the mocked ITransporter to the one that is ultimately being used by my other services. So the expectations I set up are never actually executed as the mocks end up being different instances.
Is there a way to ensure I get the same instance in both places?
Or am I going to have to create my own singleton test implementation of the ITransporter interface? (Basically creating a stub that behaves exactly like my mock does now.)
EDIT: (Answer)
As The Thom said, it appears I need to create my own class to manage the mock.
I wanted to add my solution here too in case anyone stumbled across a similar problem.
Just wrote a quick static class like this:
public class MockTransporter {
private static ITransporter mockTransporter = EasyMock.createMock(ITransporter.class);
public static final ITransporter getInstance() {
return mockTransporter;
}
}
And had to change the XML config to this:
<bean id="mockTransporter" class="MockTransporter" factory-method="getInstance" />
Oh yeah, that's a problem. When you create a new context that's like creating a new object space for Spring. The one created in your XML file is different from the one created in your handmade context. They will always produce different variables.
I've been burned on that one before.
You're only hope if you want the same ones is to manage your own singletons.
The ideal way to solve this problem would be to create the Factory as a Spring bean as well, and inject the AccountService into the Factory bean.
In general context.getBean() should be avoided in production code because it harms the concept of Inversion of Control (for more information see: Why is Spring's ApplicationContext.getBean considered bad?). It's okay to use it in test code though.

Spring:autowired field is null

I need to wire external lib class to my bean,in order to use it as singleton.
.xml config:
<bean id="myBean" class="com.my.MyBean">
<property name="someLib" value="com.ExternalBean" />
</bean>
java bean:
#Service
public class MyBean {
#Autowired
private ExternalBean externalBean;
public void setExternalBean(ExternalBean externalBean) {
this.externalBean = externalBean;
}
Further I use wired variable externalBean in public method ,in order not to instantiate it in every method call.
Problem is it null.
Do I wire bean correctly?What is mistake.
You have to define the external class as a bean in order to make #Autowired work.
<bean id="externalBean" class="some.external.package.ExternalBean">
</bean>
<bean id="myBean" class="com.my.MyBean">
</bean>
Also, if you use #Autowired you don't need the setter for it.
loodakrawa is right. A second thing that can cause a problem is, that you have a xml bean declaration for myBean and additional annotated the bean with #Service. I guess this will cause trouble as soon as use enable component scan.
I think that the better ide ais to use context path scan:
<context:component-scan base-package="some.external.package">
</context:component-scan>
Make sure that all these classes are within the package. Then mark both classes with one of the Annotations (#Repository, #Service, #Component).
One of the benefits, no setter required.
P.S: If you re using scan base you don't need to declare class as bean, annotations are enough

using spring, can I extract some part of a static method to use to set a property on a bean?

I have a static method I have no control over: MyUtils.getServiceURL() which returns a URL. I need to extract just the port from this URL to set a property on a bean:
<bean id="myBean>
<property name="defaultPort" value="?????"/>
</bean>
I can get the string value of the URL as a bean like this:
<bean id="serviceURL" class="MyUtils" factory-method="getServiceURL" />
I'm probably just going to write a method to parse the URL in myBean and extract the port. I was wondering if there was a way to avoid having to do this, and configure this directly in the spring context?
No need for custom classes, or parsers. Remember, a bean is just a class with get/is/set methods. A java.net.URL class qualifies as such.
Solution: Use a java.net.URL as a Spring-configurable bean and call it's getPort method.
Remember, in Spring, you can wire anything as a bean very easily so long as it sports methods using the get/is/set Bean convention. The java.net.URL class does such a thing.
** warning ** I'm just typing this out of my a$$, you'll have to check for any syntax shenanigans that I might be introducing in this Spring-config pseudo-code. One thing that is certain is that the concept will work with Spring 2.5 and that it relies on the util schema.
If you are using an older version of Spring, you'll have to use a PropertyPathFactoryBean. If you are using Spring 3.0, you'll want to use Spring expression language (EL), but I can't comment on the later since I'm not familiar with Spring 3.0.
In java:
int port = (new URL(MyUtils.getServiceURL()).getPort()
In Spring:
<bean id="serviceURL" class="MyUtils" factory-method="getServiceURL" />
<bean id="myURL" class="java.net.URL">
<constructor-arg>
<ref-bean="serviceURL"/>
</constructor-arg>
</bean>
<util:property-path id="defaultPort" path="myURL.port"/>
<bean id="myBean>
<property name="defaultPort" ref="defaultPort"/>
</bean>
There might be a way to consolidate all these four expressions into three or less, don't know if that will improve readability, though. The concept remains the same, though. Treat a java.net.URL instance as a bean, set its URL via its constructor, and get a hold (via Spring) of its getPort() method.
** edit **:
If you are using Spring 2.5 you can create an inline groovy bean that does all that for you. I've seen people doing that as integration glue to get rid of multitude of temp Spring bean place holders. That's the best choice IMO when you need to define a class (when it's simpler than just using Spring tags) and when you know such a class won't be used outside of Spring wiring of things.
Not I can think of. Either way, you probably have to write something to parse the port out. Since you have no control of that static method, perhaps you may want to utilize the adapter pattern to hide that static method. Doing so also makes your code easier to test because you can easily mock that external API out. For example:-
public interface URLServiceAdapter {
int getServiceURLPort();
}
public class URLServiceAdapterImpl implements URLServiceAdapter {
public int getServiceURLPort() {
return MyUtils.getServiceURL().getPort();
}
}
Your beans will then rely on your adapter class instead of MyUtils.getServiceURL() directly:-
<bean id="urlServiceAdapter" class="project.URLServiceAdapterImpl" />
That way, you can do something like this:-
#Autowired
private UrlServiceAdapter urlServiceAdapter;
...
bean.setDefaultPort(urlServiceAdapter.getServiceURLPort());
SpEL is your friend.
<bean id="myBean>
<property name="defaultPort"
value='#{ T(com.foo.MyUtils).getServiceURL().split(":")[2].split("/")[0] }'/>
</bean>
Enjoy,

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