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Spring #Service annotation with more values

I would like to ask if there is possible in spring to annotate class with #Service with more than 1 value, something like this:
#Service({"ServiceName1","ServiceName2"})
public class ClassName {
}
The reason is i want to get same class when i am calling applicationContext.getBean("ServiceName1"); or applicationContext.getBean("ServiceName2");
Thanks in advance for answers.

You can just declare your bean in a configuration class instead, and specify multiple names in the Bean annotation:
#Bean(name = { "ServiceName1", "ServiceName2" })
public ClassName myService() {
return new ClassName();
}
But if you're getting beans by name, from the application context, you've probably missed the whole point of dependency injection.

I think if we use #Component/ #Service annotations we can create only one bean instance for a class. If we need to create multiple beans for a single class we need to go with xml approach. Define the beans for the single Class in applicationContext.xml
<bean id="ServiceName1" class="<ClassName Path>">
</bean>
<bean id="ServiceName2" class="<ClassName Path>">
</bean>

SpEL: get current bean name during bean instantiation

I am attempting to use SpEL to get the name of the bean currently being instantiated to allow multiple beans of same class to be created with different properties supplied by #PropertySource. I am hoping for something like the following:
public class SampleBean {
#Value("${#{CurrentBeanName}.val}")
private String val
}
Other bean:
public class OtherBean {
#Autowired
#Qualifier(name="BeanA")
SampleBean beanA;
#Autowired
#Qualifier(name="BeanB")
SampleBean beanB;
}
properties file:
BeanA.val=VALUE A
BeanB.val=VALUE B
If I add beanName=BeanA to my properties file, I am able to get this to work with
#Value("${${beanName}.val}")
Any ideas on what to do for #{BeanName}? If this is impossible then so be it, but if it works it would be much cleaner than my current solution.
EDIT:
Or any way to pass a constant from the xml bean definition to SpEL? example:
<bean id="BeanA" class="...">
<property name="prefix" value="BeanA"/>
</bean>
java:
public class SampleBean {
#Value("${#{prefix}.val}")
private String val
}
Any sort of attribute or anything would work
EDIT2:
This is trivial in old XML based config
spring.xml:
<bean id="beanA" class="SampleBean">
<property name="val" value="${BeanA.val}"/>
</bean>
<bean id="beanB" class="SampleBean">
<property name="val" value="${BeanB.val}"/>
</bean>
SampleBean.java:
public class SampleBean {
private String val;
public void setVal (String val) {
this.val = val;
}
}
However when switching to the new #Value annotations to get rid of all the setters, it seems non-singletons with diff properties aren't supported (i.e. no way to dynamically filter #Value arguments on bean creation)

No; it is not possible to reference the current bean.
EDIT
To address your comment below, the Java Configuration equivalent of
<bean id="BeanA" class="com.my.Foo">
<property name="prefix" value="BeanA"/>
</bean>
is
#Bean
public Foo BeanA() {
Foo a = new Foo();
a.setPrefix("BeanA");
}
although, by convention, you'd probably name it beanA.

If you have singleton bean types you could just use a static final variable for the name and then reference that. But the bigger issue is that you will be breaking the Spring inversion of control principals if you begin depending on Spring bean names, which is why this sort of thing isn't done. Pretty much want to focus on creating modules and domains for your project. If you begin accessing components coming from the Spring Context directly (such as the bean name) you will find that your modules will become brittle, hard to change and very hard to reason about as they begin to depend on behaviour from seemingly unrelated modules, such as the Spring Dependency Injection Framework. Although you may have a valid use-case for doing this you just need to be very very careful.

Spring Prototype-Bean Provider without #Autowired

I have a prototype Bean which is instantiated by singleton bean with a Provider:
#Component
#Scope("prototype")
class MyPrototype {}
#Component
class MySingleton {
#Autowired
javax.inject.Provider<MyPrototype> prototypeFactory;
}
This works fine, but our company rules state that #Autowired is not allowed; the common pattern is #Resource(SingletonBeanClass.BEAN_ID).
Is it possible to annotate the Provider this way so the Spring lookup can create it?
I'm aware I can add a factory method with #Lookup, or a singleton factory bean, but I prefer the Provider.
EDIT:
I didn't get it to work this way and in the end had to edit spring.xml; see below for details.

As you have an XML configuration file, you can configure it via XML in the following way:
<bean id="myPrototype" class="some.package.MyPrototype" scope="prototype" />
<bean id="mySingleton" class="some.package.MySingleton">
<lookup-method name="getPrototypeFactory" bean="myPrototype "/>
</bean>
In this way, you have to access to the myPrototype with the getPrototypeFactory() and not directly to the property. You can even remove the annotations on those 2 classes.
For any extra details, you can look at the following blog post Injecting a prototype bean into a singleton bean

For reference, if someone comes across this via Google:
I ended up needing to declare it in the spring.xml. I tried #Lookup, but even that didn't work due to the prototype-bean referencing yet another prototype-bean.
This is how it was recommended here,
but it does not work:
#Component("proto1")
#Scope("prototype")
class MyPrototypeBean1 {
#Lookup(value="proto2")
protected MyPrototypeBean2 createBean2() { return null; }
}
#Component("proto2")
#Scope("prototype")
class MyPrototypeBean2 {
}
#Component("singleton")
class MySingleton {
#Lookup(value="proto1")
protected MyPrototypeBean1 createBean1() { return null; }
}
This results in the error message "Cannot apply #Lookup to beans without corresponding bean definition" when trying to create "innerBean...".
I assume it is due to "lookup methods cannot get replaced on beans returned from factory methods where we can't dynamically provide a subclass for them" as is quoted in the link above.
So what I ended up doing in the spring.xml:
<bean name="proto2" class="my.package.PrototypeBean2" />
<bean name="proto1" class="my.package.PrototypeBean1" >
<lookup-method name="createBean2" bean="proto2" />
</bean>
<bean name="singleton" class="my.package.SingletonBean" >
<lookup-method name="createBean1" bean="proto1" />
</bean>
And this works.
For the unit tests, I had to subclass the respective classes:
class SingletonUnitTest {
#Mock
MyPrototypeBean1 bean1;
#InjectMocks
DummySingleton sut;
#Before public void setBean1() {
sut.bean = bean1;
}
static class DummySingletonBean extends MySingeton {
MyPrototypeBean1 bean;
protected MyPrototypeBean1 createBean1() {
return bean;
}
}
}

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

Spring prototype beans in combination with singleton beans and dependency injection. Is there an approach that is configuration only?

I have a singleton bean which needs for each call of a function to return a reference to a different (new) prototype bean. The only way that I can think of doing this is to programmatically retrieve a new prototype bean instance from the BeanFactory/ApplicatioContext by invoking its getBean() method. Code sample will follow...
Is there a better way to do this? Only via configuration, hopefully? (Personally, I doubt there is...)
<bean id="protoBean" scope="prototype"
class="com.blahblah.ProtoBean" />
<bean id="singletonBean"
class="com.blahblah.SingletonBean" />
public class ProtoBean {
....
}
public class SingletonBean {
private BeanFactory factory;
public ProtoBean dispense() {
return (ProtoBean) factory.getBean("protoBean");
}
....
}

take a look at Method Injection

From Spring 3.0, we can use <aop:scoped-proxy> for dependency injection of the proper scope. Behind the scene, Spring injects proxied objects and is responsible for finding the right scope context, may it be prototype, session or request etc. See the official documentations here.
And to make life easier, Spring has also introduced proxyMode attribute for #Scope, so we are not limited to XML declarations only. For example:
#Scope(value = "prototype", proxyMode = ScopedProxyMode.INTERFACES)
Make sure to document clearly the injected bean is a proxy to warn others that getClass() and casting may not yield the expected result. Also, make sure equals() and hashCode() in the proxied class use access methods rather than directly accessing class variables.

Using method injection makes the singleton-bean class difficult to unit-test (you need to create a subclass to implement the method which gives out the dependency). Plus it's less reusable because you can't directly instantiate it, so if you're not using Spring and want to use this class, you'll need to subclass and provide the bean-returning method.
A better approach IMHO is to use a proxy, a prototype target source and a prototype target bean, as follows. Such a singleton-bean class is easily unit-testable and better reusable.
<bean id="targetPooledObject" class="pool.PooledObject" scope="prototype">
<constructor-arg value="42" />
</bean>
<bean id="prototypeTargetSource" class="org.springframework.aop.target.PrototypeTargetSource">
<property name="targetBeanName" value="targetPooledObject" />
</bean>
<bean id="pooledObject" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="targetSource" ref="prototypeTargetSource" />
</bean>
<bean id="poolConsumer" class="pool.PoolConsumer">
<property name="pooledObject" ref="pooledObject" />
</bean>
Now we can inject pooledObject into a singleton bean (poolConsumer as shown above), and for every method call that we make on that singleton bean, (e.g. every time we call poolConsumer.callPooledObjectMethod() which in turn calls pooledObject.foo()) we get a new PooledObject bean.
Following is the corresponding code:
public class PooledObject
{
private int x;
public PooledObject(int x)
{
this.x = x;
}
public void foo()
{
System.out.println("foo called");
}
}
public class PoolConsumer
{
private PooledObject pooledObject;
public PooledObject getPooledObject()
{
return pooledObject;
}
public void setPooledObject(PooledObject pooledObject)
{
this.pooledObject = pooledObject;
}
public void callPooledObjectMethod()
{
pooledObject.foo();
}
}