TinySpring 构建过程 Step6-ApplicationContext

其实 BeanFactory 已经提供了完整的功能，但是使用起来比较麻烦。现在用 ApplicationContext 做一个接口封装。

1. ApplicationContext 接口

public interface ApplicationContext extends BeanFactory {
}
​

2. AbstractApplicationContext 抽象类

public abstract class AbstractApplicationContext implements ApplicationContext {
	protected AbstractBeanFactory beanFactory;

	public AbstractApplicationContext(AbstractBeanFactory beanFactory) {
		this.beanFactory = beanFactory;
	}

	public void refresh() throws Exception{
	}

	@Override
	public Object getBean(String name) throws Exception {
		return beanFactory.getBean(name);
	}
}
	
​

3. ClassPathXmlApplicationContext xml 的 ApplicationContext，refesh() 用来初始化 Bean

public class ClassPathXmlApplicationContext extends AbstractApplicationContext {

	private String configLocation;

	public ClassPathXmlApplicationContext(String configLocation) throws Exception {
		this(configLocation, new AutowireCapableBeanFactory());
	}

	public ClassPathXmlApplicationContext(String configLocation, AbstractBeanFactory beanFactory) throws Exception {
		super(beanFactory);
		this.configLocation = configLocation;
		refresh();
	}

	@Override
	public void refresh() throws Exception {
		XmlBeanDefinitionReader xmlBeanDefinitionReader = new XmlBeanDefinitionReader(new ResourceLoader());
		xmlBeanDefinitionReader.loadBeanDefinitions(configLocation);
		for (Map.Entry<String, BeanDefinition> beanDefinitionEntry : xmlBeanDefinitionReader.getRegistry().entrySet()) {
			beanFactory.registerBeanDefinition(beanDefinitionEntry.getKey(), beanDefinitionEntry.getValue());
		}
	}

}
	
​

4. 测试代码，比之前使用更佳简便，封装了实现细节。

@Test
public void test() throws Exception {
	ApplicationContext applicationContext = new ClassPathXmlApplicationContext("tinyioc.xml");
	HelloWorldService helloWorldService = (HelloWorldService) applicationContext.getBean("helloWorldService");
	helloWorldService.helloWorld();
}
​