【IT168 专稿】

    5.实现MultiMethodControllerUrlHandlerMapping

    我们在上面讨论过了怎么实现MultiMethodControllerUrlHandlerMapping，要实现为具体的代码，我们可以通过扩展org.springframework.web.servlet.handler.AbstractUrlHandlerMapping。AbstractUrlHandlerMapping扩展了org.springframework.web.context.support.WebApplicationObjectSupport。WebApplicationObjectSupport可以获得当前WebApplicationContext。

    1. 重写initApplicationContext方法，在context中查找所有MultiActionController类型的bean,把MultiActionController的urlMethodmappings属性的key值为key值，MultiActionController实例为键值的键值对添加到一个urlMap中。

public class MultiMethodControllerUrlHandlerMapping extends AbstractUrlHandlerMapping...{
    private  Map urlMap = new HashMap();
    public void initApplicationContext() throws BeansException ...{
        initialUrlMap();
    }
    protected void initialUrlMap()throws BeansException...{
        //找查所有MultiMethodController类型和子类型的bean到一个map中,bean Name为key值 ,bean实例为value值
        Map matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
                getWebApplicationContext(),
                MultiMethodController.class, true, false);
        List controllers = null;
        if(!matchingBeans.isEmpty())...{
            controllers = new ArrayList(matchingBeans.values());
            for(int i = 0; controllers != null && i < controllers.size();i++)...{
                MultiMethodController controller = (MultiMethodController)controllers.get(i);
                Properties urlPros = controller.getUrlMethodmappings();
                Iterator itr = urlPros.keySet().iterator();
                for(;itr.hasNext();)...{
                    String url = (String)itr.next();
                    urlMap.put(url,controller);
                }
            }
        }
}