TinySpring分析二

标签：源码   spring   ioc   容器   .重构   

step5

	public void Step5() throws Exception {
		// 1.读取配置
		XmlBeanDefinitionReader xmlBeanDefinitionReader = new XmlBeanDefinitionReader();
		xmlBeanDefinitionReader.loadBeanDefinitions("bin/resources/tinyioc.xml");
		 
		// 2.初始化BeanFactory并注册bean
		BeanFactory beanFactory = new AbstractBeanFactory();
		for (Map.Entry<String, BeanDefinition> beanDefinitionEntry : xmlBeanDefinitionReader.getBeanDefinitionMap().entrySet()) {
		        ((AbstractBeanFactory)beanFactory).registerBeanDefinition(beanDefinitionEntry.getKey(), beanDefinitionEntry.getValue());
		}
		 
		// 3.获取bean
		HelloWorldServiceImpl helloWorldService = (HelloWorldServiceImpl) beanFactory.getBean("helloWorldService");
		helloWorldService.helloWorld3();
	}

public class XmlBeanDefinitionReader {

	//bean清单 就是前面说的学校里面的学生信息表
	private Map<String, BeanDefinition> beanDefinitionMap;
		
	public XmlBeanDefinitionReader(){
		beanDefinitionMap = new HashMap<String, BeanDefinition>();
	}

	public void loadBeanDefinitions(String local) throws IOException, ParserConfigurationException, SAXException {
		InputStream is = new FileInputStream(local);
		parseNode(is);
	}

/**
	 * 通过InputStream 获得每一个bean
	 * @param is
	 * @throws ParserConfigurationException
	 * @throws SAXException
	 * @throws IOException
	 */
	public void parseNode(InputStream is) throws ParserConfigurationException, SAXException, IOException {
		DocumentBuilderFactory domfac = DocumentBuilderFactory.newInstance();
		DocumentBuilder domBuilder = domfac.newDocumentBuilder();


		// 默认是工程目录
	//	InputStream is = new FileInputStream("bin/resources/tinyioc.xml");
		Document doc = domBuilder.parse(is);
		Element root = doc.getDocumentElement();
		NodeList beans = root.getChildNodes();
		for (int i = 0; i < beans.getLength(); i++) 
			if (beans.item(i) instanceof Element) {
				Element el=(Element)beans.item(i);
				parseElement(el);
			}
		is.close();
		
	}
	
	/**
	 * 分析每一个bean的id class
	 * @param el
	 */
	public void parseElement(Element el){
		String id=el.getAttribute("id");
		String classPath=el.getAttribute("class");
	//	System.out.println(id+"  "+classPath);
		BeanDefinition bd=new BeanDefinition();
		bd.setBeanClassName(classPath);
		parseProperties(el,bd);
		beanDefinitionMap.put(id, bd);
	}
	
	/**
	 * 分析每一个bean的参数  并加入到beandefinition的property里面
	 * @param el
	 * @param bd
	 */
	public void parseProperties(Element el,BeanDefinition bd){
		NodeList bl=el.getElementsByTagName("property");
		for (int i = 0; i < bl.getLength(); i++) 
			if (bl.item(i) instanceof Element) {
				Element property=(Element)bl.item(i);
				String name=property.getAttribute("name");
    		//	System.out.print("   "+name+"  ");
				if (property.getAttribute("ref")!="") {
					BeanReference br=new BeanReference(property.getAttribute("ref"));	
					PropertyValue pV=new PropertyValue(name,br);
					bd.getPropertyValues().addPropertyValue(pV);
			//		System.out.println("   "+br.getName()+"  ");
				}
				if (property.getAttribute("value")!="") {
					String value=property.getAttribute("value");
					PropertyValue pV=new PropertyValue(name, value);
					bd.getPropertyValues().addPropertyValue(pV);
				//	System.out.println(value);
				}
			}
		
	}

	public Map<String, BeanDefinition> getBeanDefinitionMap() {
		return beanDefinitionMap;
	}

step6

		// 2.初始化BeanFactory并注册bean
		BeanFactory beanFactory = new AbstractBeanFactory();
		for (Map.Entry<String, BeanDefinition> beanDefinitionEntry : xmlBeanDefinitionReader.getBeanDefinitionMap().entrySet()) {
		        ((AbstractBeanFactory)beanFactory).registerBeanDefinition(beanDefinitionEntry.getKey(), beanDefinitionEntry.getValue());
		}

<pre name="code" class="java">public void Step7() throws Exception {
		ApplicationContext ac=new ApplicationContext("bin/resources/tinyioc.xml");
		HelloWorldServiceImpl helloWorldService = (HelloWorldServiceImpl) ac.getBean("helloWorldService");
		helloWorldService.helloWorld3();
	}

package com.myspring.context;

import java.util.Map;

import com.bjsxt.spring.BeanFactory;
import com.myspring.beans.BeanDefinition;
import com.myspring.beans.factory.AbstractBeanFactory;
import com.myspring.beans.xml.XmlBeanDefinitionReader;

public class ApplicationContext implements BeanFactory {
	
	private AbstractBeanFactory abf=new AbstractBeanFactory();

	public  ApplicationContext(String local) throws Exception {
	//	InputStream is = new FileInputStream(local);
		loadBeanDefinitions(abf,local);
	}
	
	protected void loadBeanDefinitions(AbstractBeanFactory beanFactory,String configLocation) throws Exception {
		XmlBeanDefinitionReader xmlBeanDefinitionReader = new XmlBeanDefinitionReader();
		xmlBeanDefinitionReader.loadBeanDefinitions(configLocation);
		for (Map.Entry<String, BeanDefinition> beanDefinitionEntry : 
			xmlBeanDefinitionReader.getBeanDefinitionMap().entrySet()) {
			beanFactory.registerBeanDefinition(beanDefinitionEntry.getKey(), beanDefinitionEntry.getValue());
		}
	}
	@Override
	public Object getBean(String id) {
		// TODO Auto-generated method stub
		Object obj=null;
		try {
			obj = abf.getBean(id);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return obj;	
	}
}

	protected void onRefresh() throws Exception{
	     beanFactory.preInstantiateSingletons();
	  }


	public void preInstantiateSingletons() throws Exception {
		for (Iterator<String> it = this.beanDefinitionNames.iterator(); it.hasNext();) {
			String beanName = (String) it.next();
			getBean(beanName);
		}
	}

public Object getBean(String name) throws Exception {
		BeanDefinition beanDefinition = beanDefinitionMap.get(name);
		if (beanDefinition == null) {
			throw new IllegalArgumentException("No bean named " + name + " is defined");
		}
		Object bean = beanDefinition.getBean();
		if (bean == null) {                     //******************查找beanDefinition
			bean = doCreateBean(beanDefinition);
            bean = initializeBean(bean, name);
            beanDefinition.setBean(bean);
		}
		return bean;
	}


	protected Object doCreateBean(BeanDefinition beanDefinition) throws Exception {
		Object bean = createBeanInstance(beanDefinition);
		beanDefinition.setBean(bean);            //******************写入beanDefinition
		applyPropertyValues(bean, beanDefinition);
		return bean;
	}

我写的代码中,没有上面的步骤,因此即使第二次get一个已经get过得bean,仍然会产生一个新的bena!

我写的代码 下载地址

http://download.csdn.net/detail/dlf123321/7992633

参考资料

http://www.cnblogs.com/yejg1212/p/3270152.html

http://blog.csdn.net/dlf123321/article/details/39649089

TinySpring分析二

标签：源码   spring   ioc   容器   .重构   

原文地址：http://blog.csdn.net/dlf123321/article/details/40017593