CODEWITHSUNDEEP
javaspringoopdesign-patternsspring-ioc
Naren Karanam
Naren Karanam

Reputation: 61

Spring IoC: Conditional Injection in run time

How can I conditionally inject a bean externally using the framework ( not creating a factory class)?

In below scenario both childBeans will be instantiated already while but injected into parent bean in run time based on condition.

<bean id=ChildBean1>
<bean id=ChildBean2>
<parentBean name='parentBean' lazy-init="true">
   <property name='flag'>

   <somecondition flag=1/>  
   <property name='child' ref ='childBean1'/>
   <somecondition flag=2/> 
   <property name='child' ref ='childBean2'/>
</parentBean>

Upvotes: 0

Views: 1346

Answers (1)

shankarsh15
shankarsh15

Reputation: 1967

You can do it via spring expression language(SpEL):

<bean class="com.example.spring.TestBean">
    <property name="dependency" value="#{systemProperties['profile'] == 'test' ? dependencyA : dependencyB}" />
</bean>

Also it is possible using a Java Config something like below:

@Bean
public HelloBean helloBean() {
    HelloBean helloBean = new HelloBean ();
    if (condition) {
        helloBean.setDependency(dependencyA());
    } else {
        helloBean.setDependency(dependencyB());
    }
    return helloBean;
}

Upvotes: 1

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