springMVC源码解析--ViewResolverComposite视图解析器集合（二）

上一篇博客springMVC源码分析--ViewResolver视图解析器（一）中我们介绍了一些springMVC提供的很多视图解析器ViewResolver，在开发的一套springMVC系统中是可以使用多个视图的，当然就需要配置多个视图解析器了，ViewResolverComposite简单来说就是使用简单的List来保存你配置使用的视图解析器。

ViewResolverComposite中定义了两个变量：

（1）private final List<ViewResolver> viewResolvers = new ArrayList<ViewResolver>();用来存储所有的视图解析器

（2）private int order 用来配置视图解析器的使用顺序。

ViewResolverComposite的源码如下，其没有多少具体的功能，主要就是一个视图解析器集合。

public class ViewResolverComposite implements ViewResolver, Ordered, InitializingBean,
		ApplicationContextAware, ServletContextAware {

	//用来存储所有的视图解析器
	private final List<ViewResolver> viewResolvers = new ArrayList<ViewResolver>();
	//设置视图解析器的执行顺序
	private int order = Ordered.LOWEST_PRECEDENCE;

	//设置视图解析器
	public void setViewResolvers(List<ViewResolver> viewResolvers) {
		this.viewResolvers.clear();
		if (!CollectionUtils.isEmpty(viewResolvers)) {
			this.viewResolvers.addAll(viewResolvers);
		}
	}

	//获取所有的视图解析器
	public List<ViewResolver> getViewResolvers() {
		return Collections.unmodifiableList(this.viewResolvers);
	}

	//设置执行顺序
	public void setOrder(int order) {
		this.order = order;
	}

	@Override
	public int getOrder() {
		return this.order;
	}

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		for (ViewResolver viewResolver : this.viewResolvers) {
			if (viewResolver instanceof ApplicationContextAware) {
				((ApplicationContextAware)viewResolver).setApplicationContext(applicationContext);
			}
		}
	}

	@Override
	public void setServletContext(ServletContext servletContext) {
		for (ViewResolver viewResolver : this.viewResolvers) {
			if (viewResolver instanceof ServletContextAware) {
				((ServletContextAware)viewResolver).setServletContext(servletContext);
			}
		}
	}
	//初始化视图解析器
	@Override
	public void afterPropertiesSet() throws Exception {
		for (ViewResolver viewResolver : this.viewResolvers) {
			if (viewResolver instanceof InitializingBean) {
				((InitializingBean) viewResolver).afterPropertiesSet();
			}
		}
	}
	//生成View对象
	@Override
	public View resolveViewName(String viewName, Locale locale) throws Exception {
		for (ViewResolver viewResolver : this.viewResolvers) {
			View view = viewResolver.resolveViewName(viewName, locale);
			if (view != null) {
				return view;
			}
		}
		return null;
	}

}