收集Context中的Filter
@Configuration(proxyBeanMethods = false)
protected static class ZuulFilterConfiguration {
@Autowired
private Map<String, ZuulFilter> filters;
@Bean
public ZuulFilterInitializer zuulFilterInitializer(CounterFactory counterFactory,
TracerFactory tracerFactory) {
FilterLoader filterLoader = FilterLoader.getInstance();
FilterRegistry filterRegistry = FilterRegistry.instance();
return new ZuulFilterInitializer(this.filters, counterFactory, tracerFactory,
filterLoader, filterRegistry);
}
}
//filterRegistry 註冊
// org.springframework.cloud.netflix.zuul.ZuulFilterInitializer#contextInitialized
@PostConstruct
public void contextInitialized() {
log.info("Starting filter initializer");
TracerFactory.initialize(tracerFactory);
CounterFactory.initialize(counterFactory);
for (Map.Entry<String, ZuulFilter> entry : this.filters.entrySet()) {
filterRegistry.put(entry.getKey(), entry.getValue());
}
}
運行Filter
org.springframework.web.servlet.DispatcherServlet#doDispatch
org.springframework.web.servlet.DispatcherServlet#getHandler
org.springframework.cloud.netflix.zuul.web.ZuulHandlerMapping#lookupHandler
org.springframework.web.servlet.handler.AbstractUrlHandlerMapping#buildPathExposingHandler
rawHandler=org.springframework.cloud.netflix.zuul.web.ZuulController
// org.springframework.cloud.netflix.zuul.web.ZuulController#handleRequest
@Override
public ModelAndView handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
try {
// We don't care about the other features of the base class, just want to
// handle the request
return super.handleRequestInternal(request, response);
}
finally {
// @see com.netflix.zuul.context.ContextLifecycleFilter.doFilter
RequestContext.getCurrentContext().unset();
}
}
// com.netflix.zuul.http.ZuulServlet#service
@Override
public void service(javax.servlet.ServletRequest servletRequest, javax.servlet.ServletResponse servletResponse) throws ServletException, IOException {
try {
init((HttpServletRequest) servletRequest, (HttpServletResponse) servletResponse);
// Marks this request as having passed through the "Zuul engine", as opposed to servlets
// explicitly bound in web.xml, for which requests will not have the same data attached
RequestContext context = RequestContext.getCurrentContext();
context.setZuulEngineRan();
try {
preRoute();
} catch (ZuulException e) {
error(e);
postRoute();
return;
}
try {
route();
} catch (ZuulException e) {
error(e);
postRoute();
return;
}
try {
postRoute();
} catch (ZuulException e) {
error(e);
return;
}
} catch (Throwable e) {
error(new ZuulException(e, 500, "UNHANDLED_EXCEPTION_" + e.getClass().getName()));
} finally {
RequestContext.getCurrentContext().unset();
}
}
以preRoute爲例分析執行流程
/**
* executes "pre" filters
*
* @throws ZuulException
*/
void preRoute() throws ZuulException {
zuulRunner.preRoute();
}
// com.netflix.zuul.FilterProcessor#runFilters
public Object runFilters(String sType) throws Throwable {
if (RequestContext.getCurrentContext().debugRouting()) {
Debug.addRoutingDebug("Invoking {" + sType + "} type filters");
}
boolean bResult = false;
List<ZuulFilter> list = FilterLoader.getInstance().getFiltersByType(sType);
if (list != null) {
for (int i = 0; i < list.size(); i++) {
ZuulFilter zuulFilter = list.get(i);
Object result = processZuulFilter(zuulFilter);
if (result != null && result instanceof Boolean) {
bResult |= ((Boolean) result);
}
}
}
return bResult;
}
//com.netflix.zuul.FilterLoader#getFiltersByType
/**
* Returns a list of filters by the filterType specified
*
* @param filterType
* @return a List<ZuulFilter>
*/
public List<ZuulFilter> getFiltersByType(String filterType) {
List<ZuulFilter> list = hashFiltersByType.get(filterType);
if (list != null) return list;
list = new ArrayList<ZuulFilter>();
Collection<ZuulFilter> filters = filterRegistry.getAllFilters();
for (Iterator<ZuulFilter> iterator = filters.iterator(); iterator.hasNext(); ) {
ZuulFilter filter = iterator.next();
if (filter.filterType().equals(filterType)) {
list.add(filter);
}
}
Collections.sort(list); // sort by priority
hashFiltersByType.putIfAbsent(filterType, list);
return list;
}