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;
}

}