Adding a Pre-constructed Bean to a Spring Application Context

Question

I am writing a class that implements the following method:

public void run(javax.sql.DataSource dataSource);

Within this method, I wish to

Answer 1

There's a more elegant way in which you can use an external xml file and load it with file system resource then inject beans configured in it into your application context. Thus:

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.FileSystemResource;
import org.springframework.stereotype.Service;

@Service
@Order(-100)
public class XmlBeanInitializationService implements ApplicationContextAware, InitializingBean {

    private ApplicationContext applicationContext;

    @Value("${xmlConfigFileLocation}")
    private String xmlConfigFileLocation;

    @Override
    public void afterPropertiesSet() throws Exception {
        XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader((BeanDefinitionRegistry)applicationContext);
        reader.loadBeanDefinitions(new FileSystemResource(xmlConfigFileLocation));
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;

    }
}

where ${xmlConfigFileLocation} is a property specified in your application.properties file which points to the file location in your system thus:

xmlConfigFileLocation="your-file-path-anywhere-in-your-system"

and your xml file may contain:

thus when your application starts spring loads the class and loads the bean into application context.

Hope this helps someone.