了解了上述Environment的基本原理后，如何从近程服务器上加载配置到Spring的Environment中。
NacosPropertySourceLocator
顺着后面的剖析思路，咱们很天然的去找PropertySourceLocator的实现类，发现除了咱们自定义的GpJsonPropertySourceLocator以外，还有另外一个实现类NacosPropertySourceLocator.
于是，间接来看NacosPropertySourceLocator中的locate办法，代码如下。
public PropertySource<?> locate(Environment env) { this.nacosConfigProperties.setEnvironment(env); ConfigService configService = this.nacosConfigManager.getConfigService(); if (null == configService) { log.warn("no instance of config service found, can't load config from nacos"); return null; } else { //获取客户端配置的超时工夫 long timeout = (long)this.nacosConfigProperties.getTimeout(); this.nacosPropertySourceBuilder = new NacosPropertySourceBuilder(configService, timeout); //获取name属性， String name = this.nacosConfigProperties.getName(); //在Spring Cloud中，默认的name=spring.application.name。 String dataIdPrefix = this.nacosConfigProperties.getPrefix(); if (StringUtils.isEmpty(dataIdPrefix)) { dataIdPrefix = name; } if (StringUtils.isEmpty(dataIdPrefix)) { dataIdPrefix = env.getProperty("spring.application.name"); //获取spring.application.name，赋值给dataIdPrefix } //创立一个Composite属性源，能够蕴含多个PropertySource CompositePropertySource composite = new CompositePropertySource("NACOS"); this.loadSharedConfiguration(composite); //加载共享配置 //加载扩大配置 loadExtConfiguration(composite); //加载本身配置 loadApplicationConfiguration(composite, dataIdPrefix, nacosConfigProperties, env); return composite; }}上述代码的实现不难理解
- 获取nacos客户端的配置属性，并生成dataId（这个很重要，要定位nacos的配置）
- 别离调用三个办法从加载配置属性源，保留到composite组合属性源中
loadApplicationConfiguration
咱们能够先不论加载共享配置、扩大配置的办法，最终实质上都是去近程服务上读取配置，只是传入的参数不一样。
- fileExtension，示意配置文件的扩展名
- nacosGroup示意分组
- 加载
dataid=项目名称的配置 - 加载
dataid=项目名称+扩展名的配置 - 遍历以后配置的激活点（profile），别离循环加载带有profile的dataid配置
private void loadApplicationConfiguration( CompositePropertySource compositePropertySource, String dataIdPrefix, NacosConfigProperties properties, Environment environment) { String fileExtension = properties.getFileExtension(); //默认的扩大名为： properties String nacosGroup = properties.getGroup(); //获取group //加载`dataid=项目名称`的配置 loadNacosDataIfPresent(compositePropertySource, dataIdPrefix, nacosGroup, fileExtension, true); //加载`dataid=项目名称+扩展名`的配置 loadNacosDataIfPresent(compositePropertySource, dataIdPrefix + DOT + fileExtension, nacosGroup, fileExtension, true); // 遍历profile（能够有多个），依据profile加载配置 for (String profile : environment.getActiveProfiles()) { //此时的dataId=${spring.application.name}.${profile}.${fileExtension} String dataId = dataIdPrefix + SEP1 + profile + DOT + fileExtension; loadNacosDataIfPresent(compositePropertySource, dataId, nacosGroup, fileExtension, true); }}loadNacosDataIfPresent
调用loadNacosPropertySource加载存在的配置信息。
把加载之后的配置属性保留到CompositePropertySource中。
private void loadNacosDataIfPresent(final CompositePropertySource composite, final String dataId, final String group, String fileExtension, boolean isRefreshable) { //如果dataId为空，或者group为空，则间接跳过 if (null == dataId || dataId.trim().length() < 1) { return; } if (null == group || group.trim().length() < 1) { return; } //从nacos中获取属性源 NacosPropertySource propertySource = this.loadNacosPropertySource(dataId, group, fileExtension, isRefreshable); //把属性源保留到compositePropertySource中 this.addFirstPropertySource(composite, propertySource, false);}loadNacosPropertySource
private NacosPropertySource loadNacosPropertySource(final String dataId, final String group, String fileExtension, boolean isRefreshable) { if (NacosContextRefresher.getRefreshCount() != 0) { if (!isRefreshable) { //是否反对主动刷新，// 如果不反对主动刷新配置则主动从缓存获取返回(不从近程服务器加载) return NacosPropertySourceRepository.getNacosPropertySource(dataId, group); } } //结构器从配置核心获取数据 return nacosPropertySourceBuilder.build(dataId, group, fileExtension, isRefreshable);}NacosPropertySourceBuilder.build
NacosPropertySource build(String dataId, String group, String fileExtension, boolean isRefreshable) { //调用loadNacosData加载近程数据 List<PropertySource<?>> propertySources = loadNacosData(dataId, group, fileExtension); //结构NacosPropertySource(这个是Nacos自定义扩大的PropertySource，和咱们后面演示的自定义PropertySource相似)。// 相当于把从近程服务器获取的数据保留到NacosPropertySource中。 NacosPropertySource nacosPropertySource = new NacosPropertySource(propertySources, group, dataId, new Date(), isRefreshable); //把属性缓存到本地缓存 NacosPropertySourceRepository.collectNacosPropertySource(nacosPropertySource); return nacosPropertySource;}NacosPropertySourceBuilder.loadNacosData
这个办法，就是连贯近程服务器去获取配置数据的实现，要害代码是configService.getConfig
private List<PropertySource<?>> loadNacosData(String dataId, String group, String fileExtension) { String data = null; try { data = configService.getConfig(dataId, group, timeout); //加载Nacos配置数据 if (StringUtils.isEmpty(data)) { log.warn( "Ignore the empty nacos configuration and get it based on dataId[{}] & group[{}]", dataId, group); return Collections.emptyList(); } if (log.isDebugEnabled()) { log.debug(String.format( "Loading nacos data, dataId: '%s', group: '%s', data: %s", dataId, group, data)); } //对加载的数据进行解析，保留到List<PropertySource>汇合。 return NacosDataParserHandler.getInstance().parseNacosData(dataId, data, fileExtension); } catch (NacosException e) { log.error("get data from Nacos error,dataId:{} ", dataId, e); } catch (Exception e) { log.error("parse data from Nacos error,dataId:{},data:{}", dataId, data, e); } return Collections.emptyList();}阶段性总结
通过上述剖析，咱们晓得了Spring Cloud集成Nacos时的要害门路，并且晓得在启动时，Spring Cloud会从Nacos Server中加载动态数据保留到Environment汇合。
从而实现动静配置的主动注入。
Nacos客户端的数据的加载流程
配置数据的最终加载，是基于 configService.getConfig，Nacos提供的SDK来实现的。
public String getConfig(String dataId, String group, long timeoutMs) throws NacosException对于Nacos SDK的应用教程： https://nacos.io/zh-cn/docs/s...
也就是说，接下来咱们的源码剖析，间接进入到Nacos这个领域。
NacosConfigService.getConfig
@Overridepublic String getConfig(String dataId, String group, long timeoutMs) throws NacosException { return getConfigInner(namespace, dataId, group, timeoutMs);}private String getConfigInner(String tenant, String dataId, String group, long timeoutMs) throws NacosException { group = blank2defaultGroup(group); //获取group，如果为空，则为default-group ParamUtils.checkKeyParam(dataId, group); //验证申请参数 ConfigResponse cr = new ConfigResponse(); //设置响应后果 cr.setDataId(dataId); cr.setTenant(tenant); cr.setGroup(group); // 优先应用本地配置 String content = LocalConfigInfoProcessor.getFailover(agent.getName(), dataId, group, tenant); if (content != null) { //如果本地缓存中的内容不为空 LOGGER.warn("[{}] [get-config] get failover ok, dataId={}, group={}, tenant={}, config={}", agent.getName(), dataId, group, tenant, ContentUtils.truncateContent(content)); cr.setContent(content); //把内容设置到cr中。 //获取容灾配置的encryptedDataKey String encryptedDataKey = LocalEncryptedDataKeyProcessor .getEncryptDataKeyFailover(agent.getName(), dataId, group, tenant); cr.setEncryptedDataKey(encryptedDataKey); //保留到cr configFilterChainManager.doFilter(null, cr); //执行过滤(目前如同没有实现) content = cr.getContent(); //返回文件content return content; } //如果本地文件中不存在相干内容，则发动近程调用 try { ConfigResponse response = worker.getServerConfig(dataId, group, tenant, timeoutMs); //把响应内容返回 cr.setContent(response.getContent()); cr.setEncryptedDataKey(response.getEncryptedDataKey()); configFilterChainManager.doFilter(null, cr); content = cr.getContent(); return content; } catch (NacosException ioe) { if (NacosException.NO_RIGHT == ioe.getErrCode()) { throw ioe; } LOGGER.warn("[{}] [get-config] get from server error, dataId={}, group={}, tenant={}, msg={}", agent.getName(), dataId, group, tenant, ioe.toString()); } //如果呈现NacosException，且不是403异样，则尝试通过本地的快照文件去获取配置进行返回。 LOGGER.warn("[{}] [get-config] get snapshot ok, dataId={}, group={}, tenant={}, config={}", agent.getName(), dataId, group, tenant, ContentUtils.truncateContent(content)); content = LocalConfigInfoProcessor.getSnapshot(agent.getName(), dataId, group, tenant); cr.setContent(content); String encryptedDataKey = LocalEncryptedDataKeyProcessor .getEncryptDataKeyFailover(agent.getName(), dataId, group, tenant); cr.setEncryptedDataKey(encryptedDataKey); configFilterChainManager.doFilter(null, cr); content = cr.getContent(); return content;}从本地缓存读取配置
默认状况下，nacos先从本地缓存的配置中读取文件：C:\Users\mayn\nacos\config\fixed-192.168.8.133_8848-6a382560-ed4c-414c-a5e2-9d72c48f1a0e_nacos
如果本地缓存内容存在，则返回内容数据，否则返回空值。
public static String getFailover(String serverName, String dataId, String group, String tenant) { File localPath = getFailoverFile(serverName, dataId, group, tenant); if (!localPath.exists() || !localPath.isFile()) { return null; } try { return readFile(localPath); } catch (IOException ioe) { LOGGER.error("[" + serverName + "] get failover error, " + localPath, ioe); return null; }}从指定文件目录下读取文件内容。
static File getFailoverFile(String serverName, String dataId, String group, String tenant) { File tmp = new File(LOCAL_SNAPSHOT_PATH, serverName + "_nacos"); tmp = new File(tmp, "data"); if (StringUtils.isBlank(tenant)) { tmp = new File(tmp, "config-data"); } else { tmp = new File(tmp, "config-data-tenant"); tmp = new File(tmp, tenant); } return new File(new File(tmp, group), dataId);}ClientWorker.getServerConfig
ClientWorker，示意客户端的一个工作类，它负责和服务端交互。
public ConfigResponse getServerConfig(String dataId, String group, String tenant, long readTimeout) throws NacosException { ConfigResponse configResponse = new ConfigResponse(); if (StringUtils.isBlank(group)) { //如果group为空，则返回默认group group = Constants.DEFAULT_GROUP; } HttpRestResult<String> result = null; try { Map<String, String> params = new HashMap<String, String>(3); //构建申请参数 if (StringUtils.isBlank(tenant)) { params.put("dataId", dataId); params.put("group", group); } else { params.put("dataId", dataId); params.put("group", group); params.put("tenant", tenant); } //发动近程调用 result = agent.httpGet(Constants.CONFIG_CONTROLLER_PATH, null, params, agent.getEncode(), readTimeout); } catch (Exception ex) { String message = String .format("[%s] [sub-server] get server config exception, dataId=%s, group=%s, tenant=%s", agent.getName(), dataId, group, tenant); LOGGER.error(message, ex); throw new NacosException(NacosException.SERVER_ERROR, ex); } //依据响应后果实现不同的解决 switch (result.getCode()) { case HttpURLConnection.HTTP_OK: //如果响应胜利，保留快照到本地，并返回响应内容 LocalConfigInfoProcessor.saveSnapshot(agent.getName(), dataId, group, tenant, result.getData()); configResponse.setContent(result.getData()); String configType; //配置文件的类型，如text、json、yaml等 if (result.getHeader().getValue(CONFIG_TYPE) != null) { configType = result.getHeader().getValue(CONFIG_TYPE); } else { configType = ConfigType.TEXT.getType(); } configResponse.setConfigType(configType); //设置到configResponse中，后续要依据文件类型实现不同解析策略 //获取加密数据的key String encryptedDataKey = result.getHeader().getValue(ENCRYPTED_DATA_KEY); //保留 LocalEncryptedDataKeyProcessor .saveEncryptDataKeySnapshot(agent.getName(), dataId, group, tenant, encryptedDataKey); configResponse.setEncryptedDataKey(encryptedDataKey); return configResponse; case HttpURLConnection.HTTP_NOT_FOUND: //如果返回404， 清空本地快照 LocalConfigInfoProcessor.saveSnapshot(agent.getName(), dataId, group, tenant, null); LocalEncryptedDataKeyProcessor.saveEncryptDataKeySnapshot(agent.getName(), dataId, group, tenant, null); return configResponse; case HttpURLConnection.HTTP_CONFLICT: { LOGGER.error( "[{}] [sub-server-error] get server config being modified concurrently, dataId={}, group={}, " + "tenant={}", agent.getName(), dataId, group, tenant); throw new NacosException(NacosException.CONFLICT, "data being modified, dataId=" + dataId + ",group=" + group + ",tenant=" + tenant); } case HttpURLConnection.HTTP_FORBIDDEN: { LOGGER.error("[{}] [sub-server-error] no right, dataId={}, group={}, tenant={}", agent.getName(), dataId, group, tenant); throw new NacosException(result.getCode(), result.getMessage()); } default: { LOGGER.error("[{}] [sub-server-error] dataId={}, group={}, tenant={}, code={}", agent.getName(), dataId, group, tenant, result.getCode()); throw new NacosException(result.getCode(), "http error, code=" + result.getCode() + ",dataId=" + dataId + ",group=" + group + ",tenant=" + tenant); } }}ServerHttpAgent.httpGet
发动近程申请的实现。
@Overridepublic HttpRestResult<String> httpGet(String path, Map<String, String> headers, Map<String, String> paramValues, String encode, long readTimeoutMs) throws Exception { final long endTime = System.currentTimeMillis() + readTimeoutMs; injectSecurityInfo(paramValues); //注入平安信息 String currentServerAddr = serverListMgr.getCurrentServerAddr();//获取以后服务器地址 int maxRetry = this.maxRetry; //获取最大重试次数，默认3次 //配置HttpClient的属性，默认的readTimeOut超时工夫是3s HttpClientConfig httpConfig = HttpClientConfig.builder() .setReadTimeOutMillis(Long.valueOf(readTimeoutMs).intValue()) .setConTimeOutMillis(ConfigHttpClientManager.getInstance().getConnectTimeoutOrDefault(100)).build(); do { try { //设置header Header newHeaders = getSpasHeaders(paramValues, encode); if (headers != null) { newHeaders.addAll(headers); } //构建query查问条件 Query query = Query.newInstance().initParams(paramValues); //发动http申请，http://192.168.8.133:8848/nacos/v1/cs/configs HttpRestResult<String> result = NACOS_RESTTEMPLATE .get(getUrl(currentServerAddr, path), httpConfig, newHeaders, query, String.class); if (isFail(result)) { //如果申请失败， LOGGER.error("[NACOS ConnectException] currentServerAddr: {}, httpCode: {}", serverListMgr.getCurrentServerAddr(), result.getCode()); } else { // Update the currently available server addr serverListMgr.updateCurrentServerAddr(currentServerAddr); return result; } } catch (ConnectException connectException) { LOGGER.error("[NACOS ConnectException httpGet] currentServerAddr:{}, err : {}", serverListMgr.getCurrentServerAddr(), connectException.getMessage()); } catch (SocketTimeoutException socketTimeoutException) { LOGGER.error("[NACOS SocketTimeoutException httpGet] currentServerAddr:{}， err : {}", serverListMgr.getCurrentServerAddr(), socketTimeoutException.getMessage()); } catch (Exception ex) { LOGGER.error("[NACOS Exception httpGet] currentServerAddr: " + serverListMgr.getCurrentServerAddr(), ex); throw ex; } //如果服务端列表有多个，并且以后申请失败，则尝试用下一个地址进行重试 if (serverListMgr.getIterator().hasNext()) { currentServerAddr = serverListMgr.getIterator().next(); } else { maxRetry--; //重试次数递加 if (maxRetry < 0) { throw new ConnectException( "[NACOS HTTP-GET] The maximum number of tolerable server reconnection errors has been reached"); } serverListMgr.refreshCurrentServerAddr(); } } while (System.currentTimeMillis() <= endTime); LOGGER.error("no available server"); throw new ConnectException("no available server");}Nacos Server端的配置获取
客户端向服务端加载配置，调用的接口是：/nacos/v1/cs/configs ， 于是，在Nacos的源码中找到该接口
定位到Nacos源码中的ConfigController.getConfig中的办法，代码如下：
@GetMapping@Secured(action = ActionTypes.READ, parser = ConfigResourceParser.class)public void getConfig(HttpServletRequest request, HttpServletResponse response, @RequestParam("dataId") String dataId, @RequestParam("group") String group, @RequestParam(value = "tenant", required = false, defaultValue = StringUtils.EMPTY) String tenant, @RequestParam(value = "tag", required = false) String tag) throws IOException, ServletException, NacosException { // check tenant ParamUtils.checkTenant(tenant); tenant = NamespaceUtil.processNamespaceParameter(tenant); //租户，也就是namespaceid // check params ParamUtils.checkParam(dataId, group, "datumId", "content"); //查看申请参数是否为空 ParamUtils.checkParam(tag); final String clientIp = RequestUtil.getRemoteIp(request); //获取申请的ip inner.doGetConfig(request, response, dataId, group, tenant, tag, clientIp); //加载配置}inner.doGetConfig
public String doGetConfig(HttpServletRequest request, HttpServletResponse response, String dataId, String group, String tenant, String tag, String clientIp) throws IOException, ServletException { final String groupKey = GroupKey2.getKey(dataId, group, tenant); String autoTag = request.getHeader("Vipserver-Tag"); String requestIpApp = RequestUtil.getAppName(request); //申请端的利用名称 int lockResult = tryConfigReadLock(groupKey); //尝试获取以后申请配置的读锁（防止读写抵触） final String requestIp = RequestUtil.getRemoteIp(request); //申请端的ip boolean isBeta = false; //lockResult>0 ，示意CacheItem(也就是缓存的配置项)不为空，并且曾经加了读锁，意味着这个缓存数据不能被删除。 //lockResult=0 ,示意cacheItem为空，不须要加读锁 //lockResult=01 , 示意加锁失败，存在抵触。 //上面这个if，就是针对这三种状况进行解决。 if (lockResult > 0) { // LockResult > 0 means cacheItem is not null and other thread can`t delete this cacheItem FileInputStream fis = null; try { String md5 = Constants.NULL; long lastModified = 0L; //从本地缓存中，依据groupKey获取CacheItem CacheItem cacheItem = ConfigCacheService.getContentCache(groupKey); //判断是否是beta公布，也就是测试版本 if (cacheItem.isBeta() && cacheItem.getIps4Beta().contains(clientIp)) { isBeta = true; } //获取配置文件的类型 final String configType = (null != cacheItem.getType()) ? cacheItem.getType() : FileTypeEnum.TEXT.getFileType(); response.setHeader("Config-Type", configType); //返回文件类型的枚举对象 FileTypeEnum fileTypeEnum = FileTypeEnum.getFileTypeEnumByFileExtensionOrFileType(configType); String contentTypeHeader = fileTypeEnum.getContentType(); response.setHeader(HttpHeaderConsts.CONTENT_TYPE, contentTypeHeader); File file = null; ConfigInfoBase configInfoBase = null; PrintWriter out = null; if (isBeta) { //如果是测试配置 md5 = cacheItem.getMd54Beta(); lastModified = cacheItem.getLastModifiedTs4Beta(); if (PropertyUtil.isDirectRead()) { configInfoBase = persistService.findConfigInfo4Beta(dataId, group, tenant); } else { file = DiskUtil.targetBetaFile(dataId, group, tenant); //从磁盘中获取文件，失去的是一个残缺的File } response.setHeader("isBeta", "true"); } else { if (StringUtils.isBlank(tag)) { //判断tag标签是否为空，tag对应的是nacos配置核心的标签选项 if (isUseTag(cacheItem, autoTag)) { if (cacheItem.tagMd5 != null) { md5 = cacheItem.tagMd5.get(autoTag); } if (cacheItem.tagLastModifiedTs != null) { lastModified = cacheItem.tagLastModifiedTs.get(autoTag); } if (PropertyUtil.isDirectRead()) { configInfoBase = persistService.findConfigInfo4Tag(dataId, group, tenant, autoTag); } else { file = DiskUtil.targetTagFile(dataId, group, tenant, autoTag); } response.setHeader("Vipserver-Tag", URLEncoder.encode(autoTag, StandardCharsets.UTF_8.displayName())); } else {//间接走这个逻辑（默认不会配置tag属性） md5 = cacheItem.getMd5(); //获取缓存的md5 lastModified = cacheItem.getLastModifiedTs(); //获取最初更新工夫 if (PropertyUtil.isDirectRead()) { //判断是否是stamdalone模式且应用的是derby数据库，如果是，则从derby数据库加载数据 configInfoBase = persistService.findConfigInfo(dataId, group, tenant); } else { //否则，如果是数据库或者集群模式，先从本地磁盘失去文件 file = DiskUtil.targetFile(dataId, group, tenant); } //如果本地磁盘文件为空，并且configInfoBase为空，则示意配置数据不存在，间接返回null if (configInfoBase == null && fileNotExist(file)) { // FIXME CacheItem // No longer exists. It is impossible to simply calculate the push delayed. Here, simply record it as - 1. ConfigTraceService.logPullEvent(dataId, group, tenant, requestIpApp, -1, ConfigTraceService.PULL_EVENT_NOTFOUND, -1, requestIp); // pullLog.info("[client-get] clientIp={}, {}, // no data", // new Object[]{clientIp, groupKey}); response.setStatus(HttpServletResponse.SC_NOT_FOUND); response.getWriter().println("config data not exist"); return HttpServletResponse.SC_NOT_FOUND + ""; } } } else {//如果tag不为空，阐明配置文件设置了tag标签 if (cacheItem.tagMd5 != null) { md5 = cacheItem.tagMd5.get(tag); } if (cacheItem.tagLastModifiedTs != null) { Long lm = cacheItem.tagLastModifiedTs.get(tag); if (lm != null) { lastModified = lm; } } if (PropertyUtil.isDirectRead()) { configInfoBase = persistService.findConfigInfo4Tag(dataId, group, tenant, tag); } else { file = DiskUtil.targetTagFile(dataId, group, tenant, tag); } if (configInfoBase == null && fileNotExist(file)) { // FIXME CacheItem // No longer exists. It is impossible to simply calculate the push delayed. Here, simply record it as - 1. ConfigTraceService.logPullEvent(dataId, group, tenant, requestIpApp, -1, ConfigTraceService.PULL_EVENT_NOTFOUND, -1, requestIp); // pullLog.info("[client-get] clientIp={}, {}, // no data", // new Object[]{clientIp, groupKey}); response.setStatus(HttpServletResponse.SC_NOT_FOUND); response.getWriter().println("config data not exist"); return HttpServletResponse.SC_NOT_FOUND + ""; } } } //把获取的数据后果设置到response中返回 response.setHeader(Constants.CONTENT_MD5, md5); // Disable cache. response.setHeader("Pragma", "no-cache"); response.setDateHeader("Expires", 0); response.setHeader("Cache-Control", "no-cache,no-store"); if (PropertyUtil.isDirectRead()) { response.setDateHeader("Last-Modified", lastModified); } else { fis = new FileInputStream(file); response.setDateHeader("Last-Modified", file.lastModified()); } //如果是单机模式，间接把数据写回到客户端 if (PropertyUtil.isDirectRead()) { out = response.getWriter(); out.print(configInfoBase.getContent()); out.flush(); out.close(); } else {//否则，通过trasferTo fis.getChannel() .transferTo(0L, fis.getChannel().size(), Channels.newChannel(response.getOutputStream())); } LogUtil.PULL_CHECK_LOG.warn("{}|{}|{}|{}", groupKey, requestIp, md5, TimeUtils.getCurrentTimeStr()); final long delayed = System.currentTimeMillis() - lastModified; // TODO distinguish pull-get && push-get /* Otherwise, delayed cannot be used as the basis of push delay directly, because the delayed value of active get requests is very large. */ ConfigTraceService.logPullEvent(dataId, group, tenant, requestIpApp, lastModified, ConfigTraceService.PULL_EVENT_OK, delayed, requestIp); } finally { releaseConfigReadLock(groupKey); //开释锁 IoUtils.closeQuietly(fis); } } else if (lockResult == 0) { //阐明缓存为空， // FIXME CacheItem No longer exists. It is impossible to simply calculate the push delayed. Here, simply record it as - 1. ConfigTraceService .logPullEvent(dataId, group, tenant, requestIpApp, -1, ConfigTraceService.PULL_EVENT_NOTFOUND, -1, requestIp); response.setStatus(HttpServletResponse.SC_NOT_FOUND); response.getWriter().println("config data not exist"); return HttpServletResponse.SC_NOT_FOUND + ""; } else {// PULL_LOG.info("[client-get] clientIp={}, {}, get data during dump", clientIp, groupKey); response.setStatus(HttpServletResponse.SC_CONFLICT); response.getWriter().println("requested file is being modified, please try later."); return HttpServletResponse.SC_CONFLICT + ""; } return HttpServletResponse.SC_OK + "";}persistService.findConfigInfo
从derby数据库中获取数据内容,这个就是一个根本的数据查问操作。
@Overridepublic ConfigInfo findConfigInfo(final String dataId, final String group, final String tenant) { final String tenantTmp = StringUtils.isBlank(tenant) ? StringUtils.EMPTY : tenant; final String sql = "SELECT ID,data_id,group_id,tenant_id,app_name,content,md5,type FROM config_info " + " WHERE data_id=? AND group_id=? AND tenant_id=?"; final Object[] args = new Object[] {dataId, group, tenantTmp}; return databaseOperate.queryOne(sql, args, CONFIG_INFO_ROW_MAPPER); }DiskUtil.targetFile
从磁盘目录中获取指标文件，间接依据dataId/group/tenant ，查找指定目录下的文件即可
public static File targetFile(String dataId, String group, String tenant) { File file = null; if (StringUtils.isBlank(tenant)) { file = new File(EnvUtil.getNacosHome(), BASE_DIR); } else { file = new File(EnvUtil.getNacosHome(), TENANT_BASE_DIR); file = new File(file, tenant); } file = new File(file, group); file = new File(file, dataId); return file;}至此，NacosPropertySourceLocator 实现了从Nacos Server上动静获取配置并缓存到本地，从而实现Nacos动静配置获取的能力！
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