一、实体bean的定义 回顾一下我们需要定义的4个标签

• 定义注册中心标签：

• 定义服务协议标签

• 定义服务提供标签：

    或者
    

• 定义服务引用标签：

UML图设计如下

• RegistyConfig、ServiceConfig、RefererConfig分别继承自抽象类AbstractConfig，并分别定义了三个标签的相关属性。ServiceConfigBean、RefererConfigBean用于实现spring的相关接口，达到对配置文件中bean进行处理的目的。

二、定义xsd文件（xmen.xsd）

三、定义handler处理文件（spring.schemas和spring.handlers）

http\://www.solid4j.com/schema/xmen.xsd=META-INF/xmen.xsdhttp\://www.solid4j.com/schema/xmen=com.solid4j.xmen.config.spring.handler.XmenNamespaceHandler

四、编写具体的Handler类

public class XmenNamespaceHandler extends NamespaceHandlerSupport {    @Override    public void init() {        registerBeanDefinitionParser("registry", new XmenBeanDefinitionParser(RegistryConfig.class, true));        registerBeanDefinitionParser("protocol", new XmenBeanDefinitionParser(ProtocolConfig.class, true));        registerBeanDefinitionParser("service", new XmenBeanDefinitionParser(ServiceConfigBean.class, true));        registerBeanDefinitionParser("referer", new XmenBeanDefinitionParser(RefererConfigBean.class, false));    }}

public class XmenBeanDefinitionParser implements BeanDefinitionParser {    private static final Logger LOGGER = LoggerFactory.getLogger(BeanDefinitionParser.class);    private final Class
     beanClass;    private final boolean required;    public XmenBeanDefinitionParser(Class
     beanClass, boolean required) {        this.beanClass = beanClass;        this.required = required;    }    @Override    public BeanDefinition parse(Element element, ParserContext parseContext) {        try {            return parse(element, parseContext, beanClass, required);        } catch (ClassNotFoundException e) {            e.printStackTrace();        }        return null;    }    private BeanDefinition parse(Element element, ParserContext parserContext, Class
     beanClass, boolean required) throws ClassNotFoundException {        RootBeanDefinition bd = new RootBeanDefinition();        bd.setBeanClass(beanClass);        bd.setLazyInit(false);        String id = element.getAttribute("id");        if ((id == null || id.length() == 0) && required) {            String generatedBeanName = element.getAttribute("name");            if (generatedBeanName == null || generatedBeanName.length() == 0) {                generatedBeanName = element.getAttribute("class");            }            if (generatedBeanName == null || generatedBeanName.length() == 0) {                generatedBeanName = beanClass.getName();            }            id = generatedBeanName;            int counter = 2;            while (parserContext.getRegistry().containsBeanDefinition(id)) {                id = generatedBeanName + (counter++);            }        }        if (id != null) {            if (parserContext.getRegistry().containsBeanDefinition(id)) {                throw new IllegalStateException("Duplicate spring bean config, id = " + id);            }            parserContext.getRegistry().registerBeanDefinition(id, bd);        }        bd.getPropertyValues().addPropertyValue("id", id);                if(ServiceConfigBean.class.equals(beanClass)) {            String className = element.getAttribute("class");            if(className != null && className.length() > 0) {                RootBeanDefinition classDefinition = new RootBeanDefinition();                classDefinition.setBeanClass(Class.forName(className, true, Thread.currentThread().getContextClassLoader()));                classDefinition.setLazyInit(false);                bd.getPropertyValues().addPropertyValue("ref", new BeanDefinitionHolder(classDefinition, id + "Impl"));            }        }        for (Method setter : beanClass.getMethods()) {            String name = setter.getName();            if (name.length() <= 3 || !name.startsWith("set") || !Modifier.isPublic(setter.getModifiers())) {                continue;            }            String property = name.substring(3, 4).toLowerCase() + name.substring(4);            if ("id".equals(property)) {                bd.getPropertyValues().addPropertyValue("id", id);                continue;            }            String value = element.getAttribute(property);            value = value.trim();            if (value.length() == 0 || value == null) {                continue;            }            Object reference;            if ("ref".equals(property)) {                reference = new RuntimeBeanReference(value);            } else {                reference = new TypedStringValue(value);            }            bd.getPropertyValues().addPropertyValue(property, reference);        }        return bd;    }}