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.
- For values as dependency (like simple String) you can do <property name="brand" value="MRF"/> or <property name="bat" ref="myBat"/>
- 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)
- Also note p namespace does not have any schema reference.
Entire Spring configuration bean looks like -
<?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.
<?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
<?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.
