I'm a newbie to spring and wonder how java based configs can be converted to xml based bean configs. I know that annotation based configs are more used now a days. But my requirement is to use xml based configs. Bean configuration is added below.
@Bean
DataStoreWriter<String> dataStoreWriter(org.apache.hadoop.conf.Configuration hadoopConfiguration) {
TextFileWriter writer = new TextFileWriter(hadoopConfiguration, new Path(basePath), null);
return writer;
You can create bean directly in xml configuration
<bean id="dataStoreWriter" class="TextFileWriter">
<constructor-arg index="0" ref="hadoopConfigBean"/>
<constructor-arg index="1">
<bean class="Path">
<constructor-arg index="0" value="/tmp"/>
</bean>
</constructor-arg>
</bean>
If you need non-trivial bean configuration then you can use factory method call in xml configuration
<bean id="dataStoreWriter" class="DataStoreFactory" factory-method="dataStoreWriter">
<constructor-arg index="0" ref="hadoopConfigBean"/>
<constructor-arg index="1" value="/tmp"/>
</bean>
Factory class should look like
public class DataStoreFactory {
public static DataStoreWriter<String> dataStoreWriter(Configuration hadoopConfiguration, String basePath) {
// do something here
TextFileWriter writer = new TextFileWriter(hadoopConfiguration, new Path(basePath), null);
return writer;
}
}
@Bean is a method-level annotation and a direct analog of the XML element. The annotation supports most of the attributes offered by , such as: init-method, destroy-method, autowiring, lazy-init, dependency-check, depends-on and scope.
When you annotate method @bean spring container will execute that method and register the return value as a bean within a BeanFactory. By default, the bean name will be the same as the method name.
@Configuration
public class AppConfig {
@Bean
public TransferService transferService() {
return new TransferServiceImpl();
}
}
Note :Use @bean along with @configuration