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怎么在springcloud中使用Zuul實(shí)現(xiàn)動態(tài)路由
怎么在springcloud中使用Zuul實(shí)現(xiàn)動態(tài)路由？很多新手對此不是很清楚，為了幫助大家解決這個(gè)難題，下面小編將為大家詳細(xì)講解，有這方面需求的人可以來學(xué)習(xí)下，希望你能有所收獲。
為察哈爾右翼后等地區(qū)用戶提供了全套網(wǎng)頁設(shè)計(jì)制作服務(wù)，及察哈爾右翼后網(wǎng)站建設(shè)行業(yè)解決方案。主營業(yè)務(wù)為網(wǎng)站建設(shè)、成都網(wǎng)站制作、察哈爾右翼后網(wǎng)站設(shè)計(jì)，以傳統(tǒng)方式定制建設(shè)網(wǎng)站，并提供域名空間備案等一條龍服務(wù)，秉承以專業(yè)、用心的態(tài)度為用戶提供真誠的服務(wù)。我們深信只要達(dá)到每一位用戶的要求，就會得到認(rèn)可，從而選擇與我們長期合作。這樣，我們也可以走得更遠(yuǎn)！
傳統(tǒng)互聯(lián)網(wǎng)架構(gòu)圖
上圖是沒有網(wǎng)關(guān)參與的一個(gè)最典型的互聯(lián)網(wǎng)架構(gòu)(本文中統(tǒng)一使用book代表應(yīng)用實(shí)例，即真正提供服務(wù)的一個(gè)業(yè)務(wù)系統(tǒng))
加入eureka的架構(gòu)圖
book注冊到eureka注冊中心中，zuul本身也連接著同一個(gè)eureka，可以拉取book眾多實(shí)例的列表。服務(wù)中心的注冊發(fā)現(xiàn)一直是值得推崇的一種方式，但是不適用與網(wǎng)關(guān)產(chǎn)品。因?yàn)槲覀兊木W(wǎng)關(guān)是面向眾多的其他部門的已有或是異構(gòu)架構(gòu)的系統(tǒng)，不應(yīng)該強(qiáng)求其他系統(tǒng)都使用eureka，這樣是有侵入性的設(shè)計(jì)。
最終架構(gòu)圖
要強(qiáng)調(diào)的一點(diǎn)是，gateway最終也會部署多個(gè)實(shí)例，達(dá)到分布式的效果，在架構(gòu)圖中沒有畫出，請大家自行腦補(bǔ)。
本博客的示例使用最后一章架構(gòu)圖為例，帶來動態(tài)路由的實(shí)現(xiàn)方式，會有具體的代碼。
動態(tài)路由
動態(tài)路由需要達(dá)到可持久化配置，動態(tài)刷新的效果。如架構(gòu)圖所示，不僅要能滿足從spring的配置文件properties加載路由信息，還需要從數(shù)據(jù)庫加載我們的配置。另外一點(diǎn)是，路由信息在容器啟動時(shí)就已經(jīng)加載進(jìn)入了內(nèi)存，我們希望配置完成后，實(shí)施發(fā)布，動態(tài)刷新內(nèi)存中的路由信息，達(dá)到不停機(jī)維護(hù)路由信息的效果。
zuul–HelloWorldDemo
項(xiàng)目結(jié)構(gòu)
com.sinosoft zuul-gateway-demo pom 1.0 org.springframework.boot spring-boot-starter-parent 1.5.2.RELEASE gateway book org.springframework.cloud spring-cloud-dependencies Camden.SR6 pom import
tip：springboot-1.5.2對應(yīng)的springcloud的版本需要使用Camden.SR6，一開始想專門寫這個(gè)demo時(shí)，只替換了springboot的版本1.4.0->1.5.2，結(jié)果啟動就報(bào)錯(cuò)了，最后發(fā)現(xiàn)是版本不兼容的鍋。
gateway項(xiàng)目：
啟動類：GatewayApplication.java
@EnableZuulProxy
@SpringBootApplication
public class GatewayApplication {
public static void main(String[] args) {
SpringApplication.run(GatewayApplication.class, args);
}
}配置：application.properties
#配置在配置文件中的路由信息 zuul.routes.books.url=http://localhost:8090 zuul.routes.books.path=/books/** #不使用注冊中心,會帶來侵入性 ribbon.eureka.enabled=false #網(wǎng)關(guān)端口 server.port=8080
book項(xiàng)目：
啟動類：BookApplication.java
@RestController
@SpringBootApplication
public class BookApplication {
@RequestMapping(value = "/available")
public String available() {
System.out.println("Spring in Action");
return "Spring in Action";
}
@RequestMapping(value = "/checked-out")
public String checkedOut() {
return "Spring Boot in Action";
}
public static void main(String[] args) {
SpringApplication.run(BookApplication.class, args);
}
}配置類：application.properties
server.port=8090
測試訪問：http://localhost:8080/books/available
上述demo是一個(gè)簡單的靜態(tài)路由，簡單看下源碼，zuul是怎么做到轉(zhuǎn)發(fā)，路由的。
@Configuration
@EnableConfigurationProperties({ ZuulProperties.class })
@ConditionalOnClass(ZuulServlet.class)
@Import(ServerPropertiesAutoConfiguration.class)
public class ZuulConfiguration {
@Autowired
//zuul的配置文件,對應(yīng)了application.properties中的配置信息
protected ZuulProperties zuulProperties;
@Autowired
protected ServerProperties server;
@Autowired(required = false)
private ErrorController errorController;
@Bean
public HasFeatures zuulFeature() {
return HasFeatures.namedFeature("Zuul (Simple)", ZuulConfiguration.class);
}
//核心類，路由定位器，最最重要
@Bean
@ConditionalOnMissingBean(RouteLocator.class)
public RouteLocator routeLocator() {
//默認(rèn)配置的實(shí)現(xiàn)是SimpleRouteLocator.class
return new SimpleRouteLocator(this.server.getServletPrefix(),
this.zuulProperties);
}
//zuul的控制器，負(fù)責(zé)處理鏈路調(diào)用
@Bean
public ZuulController zuulController() {
return new ZuulController();
}
//MVC HandlerMapping that maps incoming request paths to remote services.
@Bean
public ZuulHandlerMapping zuulHandlerMapping(RouteLocator routes) {
ZuulHandlerMapping mapping = new ZuulHandlerMapping(routes, zuulController());
mapping.setErrorController(this.errorController);
return mapping;
}
//注冊了一個(gè)路由刷新監(jiān)聽器，默認(rèn)實(shí)現(xiàn)是ZuulRefreshListener.class，這個(gè)是我們動態(tài)路由的關(guān)鍵
@Bean
public ApplicationListener zuulRefreshRoutesListener() {
return new ZuulRefreshListener();
}
@Bean
@ConditionalOnMissingBean(name = "zuulServlet")
public ServletRegistrationBean zuulServlet() {
ServletRegistrationBean servlet = new ServletRegistrationBean(new ZuulServlet(),
this.zuulProperties.getServletPattern());
// The whole point of exposing this servlet is to provide a route that doesn't
// buffer requests.
servlet.addInitParameter("buffer-requests", "false");
return servlet;
}
// pre filters
@Bean
public ServletDetectionFilter servletDetectionFilter() {
return new ServletDetectionFilter();
}
@Bean
public FormBodyWrapperFilter formBodyWrapperFilter() {
return new FormBodyWrapperFilter();
}
@Bean
public DebugFilter debugFilter() {
return new DebugFilter();
}
@Bean
public Servlet30WrapperFilter servlet30WrapperFilter() {
return new Servlet30WrapperFilter();
}
// post filters
@Bean
public SendResponseFilter sendResponseFilter() {
return new SendResponseFilter();
}
@Bean
public SendErrorFilter sendErrorFilter() {
return new SendErrorFilter();
}
@Bean
public SendForwardFilter sendForwardFilter() {
return new SendForwardFilter();
}
@Configuration
protected static class ZuulFilterConfiguration {
@Autowired
private Map filters;
@Bean
public ZuulFilterInitializer zuulFilterInitializer() {
return new ZuulFilterInitializer(this.filters);
}
}
//上面提到的路由刷新監(jiān)聽器
private static class ZuulRefreshListener
implements ApplicationListener {
@Autowired
private ZuulHandlerMapping zuulHandlerMapping;
private HeartbeatMonitor heartbeatMonitor = new HeartbeatMonitor();
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ContextRefreshedEvent
|| event instanceof RefreshScopeRefreshedEvent
|| event instanceof RoutesRefreshedEvent) {
//設(shè)置為臟,下一次匹配到路徑時(shí)，如果發(fā)現(xiàn)為臟，則會去刷新路由信息
this.zuulHandlerMapping.setDirty(true);
}
else if (event instanceof HeartbeatEvent) {
if (this.heartbeatMonitor.update(((HeartbeatEvent) event).getValue())) {
this.zuulHandlerMapping.setDirty(true);
}
}
}
}
} 我們要解決動態(tài)路由的難題，第一步就得理解路由定位器的作用。
很失望，因?yàn)閺慕涌陉P(guān)系來看，spring考慮到了路由刷新的需求，但是默認(rèn)實(shí)現(xiàn)的SimpleRouteLocator沒有實(shí)現(xiàn)RefreshableRouteLocator接口，看來我們只能借鑒DiscoveryClientRouteLocator去改造SimpleRouteLocator使其具備刷新能力。
public interface RefreshableRouteLocator extends RouteLocator {
void refresh();
}DiscoveryClientRouteLocator比SimpleRouteLocator多了兩個(gè)功能，第一是從DiscoveryClient（如Eureka）發(fā)現(xiàn)路由信息，之前的架構(gòu)圖已經(jīng)給大家解釋清楚了，我們不想使用eureka這種侵入式的網(wǎng)關(guān)模塊，所以忽略它，第二是實(shí)現(xiàn)了RefreshableRouteLocator接口，能夠?qū)崿F(xiàn)動態(tài)刷新。
對SimpleRouteLocator.class的源碼加一些注釋，方便大家閱讀：
public class SimpleRouteLocator implements RouteLocator {
//配置文件中的路由信息配置
private ZuulProperties properties;
//路徑正則配置器,即作用于path:/books/**
private PathMatcher pathMatcher = new AntPathMatcher();
private String dispatcherServletPath = "/";
private String zuulServletPath;
private AtomicReference> routes = new AtomicReference<>();
public SimpleRouteLocator(String servletPath, ZuulProperties properties) {
this.properties = properties;
if (servletPath != null && StringUtils.hasText(servletPath)) {
this.dispatcherServletPath = servletPath;
}
this.zuulServletPath = properties.getServletPath();
}
//路由定位器和其他組件的交互，是最終把定位的Routes以list的方式提供出去,核心實(shí)現(xiàn)
@Override
public List getRoutes() {
if (this.routes.get() == null) {
this.routes.set(locateRoutes());
}
List values = new ArrayList<>();
for (String url : this.routes.get().keySet()) {
ZuulRoute route = this.routes.get().get(url);
String path = route.getPath();
values.add(getRoute(route, path));
}
return values;
}
@Override
public Collection getIgnoredPaths() {
return this.properties.getIgnoredPatterns();
}
//這個(gè)方法在網(wǎng)關(guān)產(chǎn)品中也很重要，可以根據(jù)實(shí)際路徑匹配到Route來進(jìn)行業(yè)務(wù)邏輯的操作，進(jìn)行一些加工
@Override
public Route getMatchingRoute(final String path) {
if (log.isDebugEnabled()) {
log.debug("Finding route for path: " + path);
}
if (this.routes.get() == null) {
this.routes.set(locateRoutes());
}
if (log.isDebugEnabled()) {
log.debug("servletPath=" + this.dispatcherServletPath);
log.debug("zuulServletPath=" + this.zuulServletPath);
log.debug("RequestUtils.isDispatcherServletRequest()="
+ RequestUtils.isDispatcherServletRequest());
log.debug("RequestUtils.isZuulServletRequest()="
+ RequestUtils.isZuulServletRequest());
}
String adjustedPath = adjustPath(path);
ZuulRoute route = null;
if (!matchesIgnoredPatterns(adjustedPath)) {
for (Entry entry : this.routes.get().entrySet()) {
String pattern = entry.getKey();
log.debug("Matching pattern:" + pattern);
if (this.pathMatcher.match(pattern, adjustedPath)) {
route = entry.getValue();
break;
}
}
}
if (log.isDebugEnabled()) {
log.debug("route matched=" + route);
}
return getRoute(route, adjustedPath);
}
private Route getRoute(ZuulRoute route, String path) {
if (route == null) {
return null;
}
String targetPath = path;
String prefix = this.properties.getPrefix();
if (path.startsWith(prefix) && this.properties.isStripPrefix()) {
targetPath = path.substring(prefix.length());
}
if (route.isStripPrefix()) {
int index = route.getPath().indexOf("*") - 1;
if (index > 0) {
String routePrefix = route.getPath().substring(0, index);
targetPath = targetPath.replaceFirst(routePrefix, "");
prefix = prefix + routePrefix;
}
}
Boolean retryable = this.properties.getRetryable();
if (route.getRetryable() != null) {
retryable = route.getRetryable();
}
return new Route(route.getId(), targetPath, route.getLocation(), prefix,
retryable,
route.isCustomSensitiveHeaders() ? route.getSensitiveHeaders() : null);
}
//注意這個(gè)類并沒有實(shí)現(xiàn)refresh接口，但是卻提供了一個(gè)protected級別的方法,旨在讓子類不需要重復(fù)維護(hù)一個(gè)private AtomicReference> routes = new AtomicReference<>();也可以達(dá)到刷新的效果
protected void doRefresh() {
this.routes.set(locateRoutes());
}
//具體就是在這兒定位路由信息的，我們之后從數(shù)據(jù)庫加載路由信息，主要也是從這兒改寫
/**
* Compute a map of path pattern to route. The default is just a static map from the
* {@link ZuulProperties}, but subclasses can add dynamic calculations.
*/
protected Map locateRoutes() {
LinkedHashMap routesMap = new LinkedHashMap();
for (ZuulRoute route : this.properties.getRoutes().values()) {
routesMap.put(route.getPath(), route);
}
return routesMap;
}
protected boolean matchesIgnoredPatterns(String path) {
for (String pattern : this.properties.getIgnoredPatterns()) {
log.debug("Matching ignored pattern:" + pattern);
if (this.pathMatcher.match(pattern, path)) {
log.debug("Path " + path + " matches ignored pattern " + pattern);
return true;
}
}
return false;
}
private String adjustPath(final String path) {
String adjustedPath = path;
if (RequestUtils.isDispatcherServletRequest()
&& StringUtils.hasText(this.dispatcherServletPath)) {
if (!this.dispatcherServletPath.equals("/")) {
adjustedPath = path.substring(this.dispatcherServletPath.length());
log.debug("Stripped dispatcherServletPath");
}
}
else if (RequestUtils.isZuulServletRequest()) {
if (StringUtils.hasText(this.zuulServletPath)
&& !this.zuulServletPath.equals("/")) {
adjustedPath = path.substring(this.zuulServletPath.length());
log.debug("Stripped zuulServletPath");
}
}
else {
// do nothing
}
log.debug("adjustedPath=" + path);
return adjustedPath;
}
} 重寫過后的自定義路由定位器如下：
public class CustomRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator{
public final static Logger logger = LoggerFactory.getLogger(CustomRouteLocator.class);
private JdbcTemplate jdbcTemplate;
private ZuulProperties properties;
public void setJdbcTemplate(JdbcTemplate jdbcTemplate){
this.jdbcTemplate = jdbcTemplate;
}
public CustomRouteLocator(String servletPath, ZuulProperties properties) {
super(servletPath, properties);
this.properties = properties;
logger.info("servletPath:{}",servletPath);
}
//父類已經(jīng)提供了這個(gè)方法，這里寫出來只是為了說明這一個(gè)方法很重要?。?！
// @Override
// protected void doRefresh() {
// super.doRefresh();
// }
@Override
public void refresh() {
doRefresh();
}
@Override
protected Map locateRoutes() {
LinkedHashMap routesMap = new LinkedHashMap();
//從application.properties中加載路由信息
routesMap.putAll(super.locateRoutes());
//從db中加載路由信息
routesMap.putAll(locateRoutesFromDB());
//優(yōu)化一下配置
LinkedHashMap values = new LinkedHashMap<>();
for (Map.Entry entry : routesMap.entrySet()) {
String path = entry.getKey();
// Prepend with slash if not already present.
if (!path.startsWith("/")) {
path = "/" + path;
}
if (StringUtils.hasText(this.properties.getPrefix())) {
path = this.properties.getPrefix() + path;
if (!path.startsWith("/")) {
path = "/" + path;
}
}
values.put(path, entry.getValue());
}
return values;
}
private Map locateRoutesFromDB(){
Map routes = new LinkedHashMap<>();
List results = jdbcTemplate.query("select * from gateway_api_define where enabled = true ",new BeanPropertyRowMapper<>(ZuulRouteVO.class));
for (ZuulRouteVO result : results) {
if(org.apache.commons.lang3.StringUtils.isBlank(result.getPath()) || org.apache.commons.lang3.StringUtils.isBlank(result.getUrl()) ){
continue;
}
ZuulRoute zuulRoute = new ZuulRoute();
try {
org.springframework.beans.BeanUtils.copyProperties(result,zuulRoute);
} catch (Exception e) {
logger.error("=============load zuul route info from db with error==============",e);
}
routes.put(zuulRoute.getPath(),zuulRoute);
}
return routes;
}
public static class ZuulRouteVO {
/**
* The ID of the route (the same as its map key by default).
*/
private String id;
/**
* The path (pattern) for the route, e.g. /foo/**.
*/
private String path;
/**
* The service ID (if any) to map to this route. You can specify a physical URL or
* a service, but not both.
*/
private String serviceId;
/**
* A full physical URL to map to the route. An alternative is to use a service ID
* and service discovery to find the physical address.
*/
private String url;
/**
* Flag to determine whether the prefix for this route (the path, minus pattern
* patcher) should be stripped before forwarding.
*/
private boolean stripPrefix = true;
/**
* Flag to indicate that this route should be retryable (if supported). Generally
* retry requires a service ID and ribbon.
*/
private Boolean retryable;
private Boolean enabled;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public String getServiceId() {
return serviceId;
}
public void setServiceId(String serviceId) {
this.serviceId = serviceId;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public boolean isStripPrefix() {
return stripPrefix;
}
public void setStripPrefix(boolean stripPrefix) {
this.stripPrefix = stripPrefix;
}
public Boolean getRetryable() {
return retryable;
}
public void setRetryable(Boolean retryable) {
this.retryable = retryable;
}
public Boolean getEnabled() {
return enabled;
}
public void setEnabled(Boolean enabled) {
this.enabled = enabled;
}
}
} 配置這個(gè)自定義的路由定位器：
@Configuration
public class CustomZuulConfig {
@Autowired
ZuulProperties zuulProperties;
@Autowired
ServerProperties server;
@Autowired
JdbcTemplate jdbcTemplate;
@Bean
public CustomRouteLocator routeLocator() {
CustomRouteLocator routeLocator = new CustomRouteLocator(this.server.getServletPrefix(), this.zuulProperties);
routeLocator.setJdbcTemplate(jdbcTemplate);
return routeLocator;
}
}現(xiàn)在容器啟動時(shí)，就可以從數(shù)據(jù)庫和配置文件中一起加載路由信息了，離動態(tài)路由還差最后一步，就是實(shí)時(shí)刷新，前面已經(jīng)說過了，默認(rèn)的ZuulConfigure已經(jīng)配置了事件監(jiān)聽器，我們只需要發(fā)送一個(gè)事件就可以實(shí)現(xiàn)刷新了。
public class RefreshRouteService {
@Autowired
ApplicationEventPublisher publisher;
@Autowired
RouteLocator routeLocator;
public void refreshRoute() {
RoutesRefreshedEvent routesRefreshedEvent = new RoutesRefreshedEvent(routeLocator);
publisher.publishEvent(routesRefreshedEvent);
}
}看完上述內(nèi)容是否對您有幫助呢？如果還想對相關(guān)知識有進(jìn)一步的了解或閱讀更多相關(guān)文章，請關(guān)注創(chuàng)新互聯(lián)行業(yè)資訊頻道，感謝您對創(chuàng)新互聯(lián)的支持。
新聞名稱：怎么在springcloud中使用Zuul實(shí)現(xiàn)動態(tài)路由
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