Understanding p-namespace and c-namespace in Spring

Background

 In one of the previous post on Spring Dependency Injection we saw how beans are created. We also saw c namespace and how to use it.

1. For values as dependency (like simple String) you can do <property name="brand" value="MRF"/> or <property name="bat" ref="myBat"/>
2. Instead of using property tag you can also use p namespace - <bean id="cricket" class="Cricket" p:brand="MRF" p:bat-ref="myBat" />  (don't forget to add the namespace)
3. Also note p namespace does not have any schema reference. 

Entire Spring configuration bean looks like -

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<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"   xmlns:p="http://www.springframework.org/schema/p"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://www.springframework.org/schema/beans    http://www.springframework.org/schema/beans/spring-beans.xsd">     <bean id="cricket" class="com.osfg.Cricket" p:brand="MRF" p:bat-ref="myBat" />   </beans>

In this post we will see what c name space is and how to use it.

Spring 3.1 Constructor Namespace  

As you already know by now you can do dependency injection by setters or by constructor - setter injection and constructor injection.

Let's see a simple  example of constructor based dependency injection.

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<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://www.springframework.org/schema/beans     http://www.springframework.org/schema/beans/spring-beans.xsd">     <bean id="cricket" class="com.osfg.Cricket">     <constructor-arg value="MRF"/>     <constructor-arg ref="myBat"/>   </bean>

</beans>

NOTE : The <constructor-arg> tag could take type and index to reduce ambiguity, but not name.

You can simplify above xml using c namespace

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<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"   xmlns:c="http://www.springframework.org/schema/c"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://www.springframework.org/schema/beans     http://www.springframework.org/schema/beans/spring-beans.xsd">     <bean id="cricket" class="com.osfg.Cricket"     c:brand="MRF"     c:ref-bat="myBat"/>   </beans>

NOTE : Both the “p” ad “c” namespaces do not have a schema reference in the XML header.

Related Links

• Spring dependency injection using annotation based Autowiring(OSFG)
• Spring Dependency Injection(OSFG)