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Spring : Initialization of properties before any bean creation

I have the project structure as following -
Facade -> Service-> DAO
In the DAO layer, when the beans are initialized then many dependencies are injected from a property file. Therefore, the properties file must be read first and then the remaining dao beans must be created. When the application is started then it gives an error that Spring cannot resolve a placeholder.
The DAO-application-context.xml is like-
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="prop">
<value>app.properties</value>
</property>
</bean>
<import resource = "a-dao.xml" />
<import resource = "b-dao.xml" />
<import resource = "c-dao.xml" />
Now in all the child application contexts i.e. a-dao, etc, we have-
<bean ....>
<property name = "xyz">
<value>${appValue}<value/>
</property>
<bean>
The error received is that appValue cannot be resolved. I think that it may be due to incorrect sequence of bean creation. However, the same config is working in another larger project.
I have checked Order of Spring Bean Initialization but implementing that solution would not be feasible. Is there any other way ?

Reg this Block of Configuration, property prop seems to be wrong
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="prop">
<value>app.properties</value>
</property>
</bean>
According to the Spring documentation
You could use the property location or locations to set the one or multiple values of the properties file.
So the code should be refactored to
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>app.properties</value>
</property>
</bean>

Custom function for Spring ApplicationContext

I'm heavily using Spring to develop an application and I was wondering if there's a way to register custom method which can be used when a bean is defined. Currently I'm using ClassPathXmlApplicationContext to load the bean definitions from a XLM file, then in the XML file I would like to do something like
<bean id="bean1" class="..." scope="prototype"
p:some_property='"hello" + #getCorrelativeNumber()/>
Here some_property should then be evaluated to hello0. I know I can register custom functions using StandardEvaluationContext of SpEL, however I can't figure how to make that work in the context of the ApplicationContext.
Any help is greatly appreciated.

Please refer to this blog, look at the section which shows to create an application context in which expressions are used to inject values
<bean id="engine" class="com.baeldung.spring.spel.Engine">
<property name="capacity" value="3200"/>
<property name="horsePower" value="250"/>
<property name="numberOfCylinders" value="6"/>
</bean>
<bean id="someCar" class="com.baeldung.spring.spel.Car">
<property name="make" value="Some make"/>
<property name="model" value="Some model"/>
<property name="engine" value="#{engine}"/>
<property name="horsePower" value="#{engine.horsePower}"/>
</bean>

Setting annotation based SpyMemcached configuration in spring mvc

I am new to spring framework. I want to use spy memcached in my application, but i cant find the proper annotation based configuration to set the bean. Currently i am using Memcached static object in my Controller which looks really bad programming. Please provide a simple way to implement memcache in spring configuration. just on default values of memcached "127.0.0.1:11211". Thank you.
edit.
how to convert this xml cinfiguration into proper annitation based config and what to Autowire in cintroller..
<bean name="defaultMemcachedClient" class="com.google.code.ssm.CacheFactory">
<property name="cacheClientFactory">
<bean name="cacheClientFactory" class="com.google.code.ssm.providers.spymemcached.Mem
</property>
<property name="addressProvider">
<bean class="com.google.code.ssm.config.DefaultAddressProvider">
<property name="address" value="127.0.0.1:11211" />
</bean>
</property>
<property name="configuration">
<bean class="com.google.code.ssm.providers.CacheConfiguration">
<property name="consistentHashing" value="true" />
</bean>
</property>
</bean>

Take a look at Simple Spring Memcached (SSM) library.
It provides integration to memcached (via spymemcached or xmemcached client) using:
Spring Cache annotations (#Cacheable)
custom annotations (like ReadThroughSingleCache).

Java Spring IOC bean creation value

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

How to stick with both XML and Annotation based configuration Spring

Currently i am using spring 2.5 XML based configuration for bean. Now i want to upgrade it to Spring 3.x. I want to know after upgrading to 3.x my old XML configuration will work or not. If works then can i write annotation based configuration for new work in my current project.
Example of XML configuration:
<bean id="addTestimonialController" class="com.eam.web.testimonial.AddTestimonialController" singleton="true">
<property name="branchManager" ref="branchMan"/>
<property name="userManager" ref="userMan"/>
<property name="itemManager" ref="itemMan"/>
<property name="vendorManager" ref="vendorMan"/>
<property name="categoryManager" ref="categoryMan"/>
<property name="lineupManager" ref="lineupMan"/>
<property name="testimonialManager" ref="testimonialMan"/>
<property name="categoryMenuManager" ref="categoryMenuMan"/>
<property name="setManager" ref="setMan"/>
<property name="configurationManager" ref="configMan"/>
<property name="cartManager" ref="cartMan"/>
<property name="employeeManager" ref="employeeMan"/>
<property name="employeeBranchManager" ref="employeeBranchMan"/>
<property name="orderItemManager" ref="orderItemMan"/>
<property name="orderFaxManager" ref="orderFaxMan"/>
<property name="sessionForm" value="true"/>
<property name="commandName" value="addTestimonialBean"/>
<property name="branchesVendorManager" ref="branchesVendorMan" />
<property name="commandClass" value="com.eam.bus.testimonial.TestimonialBean"/>
<property name="validator" ref="addTestimonialValidator"/>
<property name="formView" value="addtestimonial"/>
<property name="successView" value="listtestimonials.html"/>
</bean>
Please help me. Also let me know if you similar link where somebody has explained both the configuration in a single configuration file.
Appreciate your help.

You can very well use both XML based metadata and Annotation based configuration metadata in your application. The configuration metadata is the information how you tell the Spring container to instantiate, configure, and assemble the objects in your application. Configuration metadata is traditionally supplied in a simple and intuitive XML format. i.e XML based configuration metadata. Spring 2.5 introduced support for annotation-based configuration metadata.Starting with Spring 3.0, many features provided by the Spring JavaConfig project became part of the core Spring Framework. Thus, you have different ways of providing your configuration metadata of your application through XML, Annotation based and Java config from Spring 3.x versions. This link will take you in the right direction. You must have to learn IOC chapter in Spring documentation

you can use both annotation based configuration and xml based (ControllerClassNameHandlerMapping ) by specifying the order of these handlers.
for annotation based Configuration use below
<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" >
<property name="order" value="0"/>
</bean>
for annotation based configuration we have to provide location ie: where to locate annotated controllers.
<context:component-scan base-package="ur packageName" />
here package name will be the package where #Controller classes are located.
for Controller Class Name based url Mapping
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" >
<property name= "order" value="2"/>
</bean>