spring redirect 导致内存溢出问题核查

3.x 版本

这个类AbstractCachingViewResolver里面的viewCache HashMap没有限制大小

3.x：如果在 controller 返回的 view 是不固定的，如：”redirect:form.html?entityId=” + entityId，由于 entityId 的值会存在 N 个，那么会导致产生 N 个 ViewName 被缓存起来

4.x 版本及以上已经修复这个问题，代码如下

public abstract class AbstractCachingViewResolver extends WebApplicationObjectSupport implements ViewResolver {

	/** Default maximum number of entries for the view cache: 1024 */
	public static final int DEFAULT_CACHE_LIMIT = 1024;

	/** Dummy marker object for unresolved views in the cache Maps */
	private static final View UNRESOLVED_VIEW = new View() {
		@Override
		public String getContentType() {
			return null;
		}
		@Override
		public void render(Map<String, ?> model, HttpServletRequest request, HttpServletResponse response) {
		}
	};


	/** The maximum number of entries in the cache */
	private volatile int cacheLimit = DEFAULT_CACHE_LIMIT;

	/** Whether we should refrain from resolving views again if unresolved once */
	private boolean cacheUnresolved = true;

	/** Fast access cache for Views, returning already cached instances without a global lock */
	private final Map<Object, View> viewAccessCache = new ConcurrentHashMap<Object, View>(DEFAULT_CACHE_LIMIT);

	/** Map from view key to View instance, synchronized for View creation */
	@SuppressWarnings("serial")
	private final Map<Object, View> viewCreationCache =
			new LinkedHashMap<Object, View>(DEFAULT_CACHE_LIMIT, 0.75f, true) {
				@Override
				protected boolean removeEldestEntry(Map.Entry<Object, View> eldest) {
					if (size() > getCacheLimit()) {
                        // 超过限制大小，删除老数据
						viewAccessCache.remove(eldest.getKey());
						return true;
					}
					else {
						return false;
					}
				}
			};
    ......

4.x 版本

4.x 版本是这个AbstractAutoProxyCreator这个类里面的advisedBeans ConcurrentHashMap没有限制大小

问题描述：https://github.com/spring-projects/spring-boot/issues/13771

The problem is that InternalResourceViewResolver calls AutowireCapableBeanFactory.initializeBean(Object existingBean, String beanName) using the complete URL as the beanName. The bean name is then used by AbstractAutoProxyCreator.wrapIfNecessary(Object, String, Object) as the key when it caches the fact that no advice applies to it.

经测试 spring 5.0.8.RELEASE 还存在这个问题，spring 5.3.8已不存在该问题，其他版本未测试

String url = "http://localhost:8080/test?uuid" + UUID.randomUUID();
// 使用 redirect
return "redirect:" + url;
// 使用 ModelAndView
return new ModelAndView("redirect:" + url);
// 使用 RedirectView
return new ModelAndView(new RedirectView(url));