(1). 概述
在这一小节,主要剖析:ConfigService,它是由:NacosFactory构建出来的.
(2). NacosFactory
public class NacosFactory {
public static ConfigService createConfigService(Properties properties) throws NacosException {
// ***********************************************************
// 委托给了:ConfigFactory
// ***********************************************************
return ConfigFactory.createConfigService(properties);
}
}
(3). ConfigFactory
public class ConfigFactory {
public static ConfigService createConfigService(Properties properties) throws NacosException {
try {
// ************************************************************
// 通过反射,加载并且new
// ************************************************************
Class<?> driverImplClass = Class.forName("com.alibaba.nacos.client.config.NacosConfigService");
Constructor constructor = driverImplClass.getConstructor(Properties.class);
ConfigService vendorImpl = (ConfigService) constructor.newInstance(properties);
return vendorImpl;
} catch (Throwable e) {
throw new NacosException(NacosException.CLIENT_INVALID_PARAM, e);
}
}
}
(4). ConfigService
public class NacosConfigService implements ConfigService {
private static final long POST_TIMEOUT = 3000L;
private static final String EMPTY = "";
/**
* http agent
*/
private HttpAgent agent;
/**
* longpolling
*/
private ClientWorker worker;
private String namespace;
private String encode;
// ******************************************************************************
// 责任链管理者
// ******************************************************************************
private ConfigFilterChainManager configFilterChainManager = new ConfigFilterChainManager();
// ********************************************************
// 1. 构建器初始化
// 设置encode
// 获得
// ********************************************************
public NacosConfigService(Properties properties) throws NacosException {
// properties = {secretKey=, namespace=45a6112b-a866-4e92-a8d6-9e440bcdebbe, fileExtension=properties, username=, enableRemoteSyncConfig=false, configLongPollTimeout=, configRetryTime=, encode=, serverAddr=127.0.0.1:8848, maxRetry=, group=erp:test-provider, clusterName=, password=, accessKey=, endpoint=}
String encodeTmp = properties.getProperty(PropertyKeyConst.ENCODE);
if (StringUtils.isBlank(encodeTmp)) {
encode = Constants.ENCODE;
} else {
encode = encodeTmp.trim();
}
// 获得namespace
initNamespace(properties);
// ********************************************************
// 2. 最终请求Nacos会通过MetricsHttpAgent去请求的
// ********************************************************
agent = new MetricsHttpAgent(new ServerHttpAgent(properties));
agent.start();
// 3. 创建:ClientWorker(会委派给:MetricsHttpAgent)
worker = new ClientWorker(agent, configFilterChainManager, properties);
}
// ***********************************************
// 4. 获取配置信息
// ***********************************************
private String getConfigInner(
// 45a6112b-a866-4e92-a8d6-9e440bcdebbe
String tenant,
// test-provider
String dataId,
// erp:test-provider
String group,
// 3000
long timeoutMs) throws NacosException {
// 如果group为null,则,group=DEFAULT_GROUP
group = null2defaultGroup(group);
// 检查参数
ParamUtils.checkKeyParam(dataId, group);
// 返回结果
ConfigResponse cr = new ConfigResponse();
cr.setDataId(dataId);
cr.setTenant(tenant);
cr.setGroup(group);
// 优先使用本地配置
String content = LocalConfigInfoProcessor.getFailover(agent.getName(), dataId, group, tenant);
if (content != null) {
LOGGER.warn("[{}] [get-config] get failover ok, dataId={}, group={}, tenant={}, config={}", agent.getName(),
dataId, group, tenant, ContentUtils.truncateContent(content));
cr.setContent(content);
configFilterChainManager.doFilter(null, cr);
content = cr.getContent();
return content;
}
try {
// ******************************************************************
// 5. 委托给:ClientWorker
// ******************************************************************
String[] ct = worker.getServerConfig(dataId, group, tenant, timeoutMs);
// 并获得数组的第0个元素,赋值给:ConfigResponse
cr.setContent(ct[0]);
// 调用责任链,对:ConfigResponse进行处理
configFilterChainManager.doFilter(null, cr);
// 返回被责任链处理过之后的内容
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());
}
// 当抛出的异常不是NacosException时,获取本地的快照.
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);
configFilterChainManager.doFilter(null, cr);
content = cr.getContent();
return content;
} // end getConfigInner
}
(5). ClientWorker
public class ClientWorker {
public String[] getServerConfig(String dataId, String group, String tenant, long readTimeout)
throws NacosException {
// 创建返回结果
String[] ct = new String[2];
// 又做了一次group检查
if (StringUtils.isBlank(group)) {
group = Constants.DEFAULT_GROUP;
}
HttpResult result = null;
try {
// 构建请求参数
List<String> params = null;
if (StringUtils.isBlank(tenant)) {
params = new ArrayList<String>(Arrays.asList("dataId", dataId, "group", group));
} else {
params = new ArrayList<String>(Arrays.asList("dataId", dataId, "group", group, "tenant", tenant));
}
// **************************************************************
// 委托给:ServerHttpAgent,最终还是会委托给:HttpSimpleClient,这是Nacos自己基于HttpURLConnection写的一个HTTP工具
// **************************************************************
result = agent.httpGet(Constants.CONFIG_CONTROLLER_PATH, null, params, agent.getEncode(), readTimeout);
} catch (IOException e) {
// 异常处理
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, e);
throw new NacosException(NacosException.SERVER_ERROR, e);
}
switch (result.code) {
case HttpURLConnection.HTTP_OK: // 成功的情况下,把结果放在内存快照里.
LocalConfigInfoProcessor.saveSnapshot(agent.getName(), dataId, group, tenant, result.content);
// ct[0] 为返回的结果内容
ct[0] = result.content;
// ct[1] 为Config-Type(properties)
if (result.headers.containsKey(CONFIG_TYPE)) {
ct[1] = result.headers.get(CONFIG_TYPE).get(0);
} else {
ct[1] = ConfigType.TEXT.getType();
}
return ct;
case HttpURLConnection.HTTP_NOT_FOUND:
LocalConfigInfoProcessor.saveSnapshot(agent.getName(), dataId, group, tenant, null);
return ct;
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.code, result.content);
}
default: {
LOGGER.error("[{}] [sub-server-error] dataId={}, group={}, tenant={}, code={}", agent.getName(), dataId,
group, tenant, result.code);
throw new NacosException(result.code,
"http error, code=" + result.code + ",dataId=" + dataId + ",group=" + group + ",tenant=" + tenant);
}
}
}
}
(6). 启动时发起的HTTP请求
# 1. get
http://127.0.0.1:8848/nacos/v1/cs/configs?dataId=test-provider.properties&group=erp%3Atest-provider&tenant=45a6112b-a866-4e92-a8d6-9e440bcdebbe
useLocalCache=true
config-type=properties
# 2. post
http://127.0.0.1:8848/nacos/v1/cs/configs/listener
(7). 总结
好像没什么要总结的,都比较简单.
