在springboot中我們經(jīng)?？梢砸胍恍﹕tarter包來集成一些工具的使用,比如spring-boot-starter-data-redis。
使用起來很方便,那么是如何實(shí)現(xiàn)的呢?
代碼分析
我們先看注解@springbootapplication,它里面包含一個(gè)@enableautoconfiguration
繼續(xù)看@enableautoconfiguration注解
@import({autoconfigurationimportselector.class})
在這個(gè)類(autoconfigurationimportselector)里面實(shí)現(xiàn)了自動(dòng)配置的加載
主要代碼片段:
string[] selectimports(annotationmetadata annotationmetadata)方法中
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autoconfigurationimportselector.autoconfigurationentry autoconfigurationentry = this.getautoconfigurationentry(autoconfigurationmetadata, annotationmetadata); |
getautoconfigurationentry方法中:
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list<string> configurations = this.getcandidateconfigurations(annotationmetadata, attributes); protected list<string> getcandidateconfigurations(annotationmetadata metadata, annotationattributes attributes) { list<string> configurations = springfactoriesloader.loadfactorynames(this.getspringfactoriesloaderfactoryclass(), this.getbeanclassloader()); assert.notempty(configurations, "no auto configuration classes found in meta-inf/spring.factories. if you are using a custom packaging, make sure that file is correct."); return configurations;} |
最后會(huì)通過springfactoriesloader.loadspringfactories去加載meta-inf/spring.factories
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enumeration<url> urls = classloader != null ? classloader.getresources("meta-inf/spring.factories") : classloader.getsystemresources("meta-inf/spring.factories"); linkedmultivaluemap result = new linkedmultivaluemap(); |
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while(urls.hasmoreelements()) { url url = (url)urls.nextelement(); urlresource resource = new urlresource(url); properties properties = propertiesloaderutils.loadproperties(resource); iterator var6 = properties.entryset().iterator(); while(var6.hasnext()) { entry<?, ?> entry = (entry)var6.next(); string factoryclassname = ((string)entry.getkey()).trim(); string[] var9 = stringutils.commadelimitedlisttostringarray((string)entry.getvalue()); int var10 = var9.length; for(int var11 = 0; var11 < var10; ++var11) { string factoryname = var9[var11]; result.add(factoryclassname, factoryname.trim()); } } } |
zookeeperautoconfiguration
我們來實(shí)現(xiàn)一個(gè)zk的autoconfiguration
首先定義一個(gè)zookeeperautoconfiguration類
然后在meta-inf/spring.factories中加入
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org.springframework.boot.autoconfigure.enableautoconfiguration=com.fayayo.fim.zookeeper.zookeeperautoconfiguration |
接下來我們看看具體的實(shí)現(xiàn):
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@configurationproperties(prefix = "fim.register")@configurationpublic class urlregistry { private string address; private int timeout; private int sessiontimeout; public string getaddress() { if (address == null) { address = urlparam.address; } return address; } public void setaddress(string address) { this.address = address; } public int gettimeout() { if (timeout == 0) { timeout = urlparam.connecttimeout; } return timeout; } public void settimeout(int timeout) { this.timeout = timeout; } public int getsessiontimeout() { if (sessiontimeout == 0) { sessiontimeout = urlparam.registrysessiontimeout; } return sessiontimeout; } public void setsessiontimeout(int sessiontimeout) { this.sessiontimeout = sessiontimeout; }}@configuration@enableconfigurationproperties(urlregistry.class)@slf4jpublic class zookeeperautoconfiguration { @autowired private urlregistry url; @bean(value = "registry") public registry createregistry() { try { string address = url.getaddress(); int timeout = url.gettimeout(); int sessiontimeout = url.getsessiontimeout(); log.info("init zookeeperregistry,address[{}],sessiontimeout[{}],timeout[{}]", address, timeout, sessiontimeout); zkclient zkclient = new zkclient(address, sessiontimeout, timeout); return new zookeeperregistry(zkclient); } catch (zkexception e) { log.error("[zookeeperregistry] fail to connect zookeeper, cause: " + e.getmessage()); throw e; } }} |
zookeeperregistry部分實(shí)現(xiàn):
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public zookeeperregistry(zkclient zkclient) { this.zkclient = zkclient; log.info("zk register success!"); string parentpath = urlparam.zookeeper_registry_namespace; try { if (!zkclient.exists(parentpath)) { log.info("init zookeeper registry namespace"); zkclient.createpersistent(parentpath, true); } //監(jiān)聽 zkclient.subscribechildchanges(parentpath, new izkchildlistener() { //對(duì)父節(jié)點(diǎn)添加監(jiān)聽子節(jié)點(diǎn)變化。 @override public void handlechildchange(string parentpath, list<string> currentchilds) { log.info(string.format("[zookeeperregistry] service list change: path=%s, currentchilds=%s", parentpath, currentchilds.tostring())); if(watchnotify!=null){ watchnotify.notify(nodechildstourls(currentchilds)); } } }); shutdownhook.registershutdownhook(this); } catch (exception e) { e.printstacktrace(); log.error("failed to subscribe zookeeper"); } } |
具體使用
那么我們?cè)趺词褂米约簩懙膠ookeeperautoconfiguration呢
首先要在需要使用的項(xiàng)目中引入依賴
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<dependency> <groupid>com.fayayo</groupid> <artifactid>fim-registry-zookeeper</artifactid> <version>0.0.1-snapshot</version> </dependency> |
然后配置參數(shù)
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fim: register: address: 192.168.88.129:2181 timeout: 2000 |
如果不配置會(huì)有默認(rèn)的參數(shù)
具體使用的時(shí)候只需要在bean中注入就可以了,比如
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@autowired private registry registry; public list<url> getall(){ list<url>list=cache.get(key); if(collectionutils.isempty(list)){ list=registry.discover(); cache.put(key,list); } return list; } |
完整代碼
https://github.com/lizu18xz/fim.git
總結(jié)
以上所述是小編給大家介紹的springboot 中 autoconfiguration的使用方法，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)服務(wù)器之家網(wǎng)站的支持！
如果你覺得本文對(duì)你有幫助，歡迎轉(zhuǎn)載，煩請(qǐng)注明出處，謝謝！原文鏈接：https://www.imooc.com/article/285008
