EurekaServerConfig创建过程
这一篇我们来看看EurekaServerConfig是如何创建的。只看重点~
EurekaServerConfig eurekaServerConfig = new DefaultEurekaServerConfig();
这里创建了一个DefaultEurekaServerConfig实现类，点进去看看~
private static final String ARCHAIUS_DEPLOYMENT_ENVIRONMENT = "archaius.deployment.environment";
public DefaultEurekaServerConfig() {
init();
}
private void init() {
String env = ConfigurationManager.getConfigInstance().getString(
EUREKA_ENVIRONMENT, TEST);
ConfigurationManager.getConfigInstance().setProperty(
ARCHAIUS_DEPLOYMENT_ENVIRONMENT, env);
String eurekaPropsFile = EUREKA_PROPS_FILE.get();
try {
ConfigurationManager
.loadCascadedPropertiesFromResources(eurekaPropsFile);
} catch (IOException e) {
logger.warn(
"Cannot find the properties specified : {}. This may be okay if there are other environment "
+ "specific properties or the configuration is installed with a different mechanism.",
eurekaPropsFile);
}
}
可以看到这里先拿到了Eureka的环境，这里是从环境初始化的方法里面设置的，然后又把env设置到了archaius.deployment.environment参数中。接着又从配置中拿到了Eureka配置文件的文件名，最后又调用了ConfigurationManager .loadCascadedPropertiesFromResources(eurekaPropsFile);方法加载配置，我们继续跟进。
static volatile AbstractConfiguration instance = null;
public static void loadCascadedPropertiesFromResources(String configName) throws IOException {
Properties props = loadCascadedProperties(configName);
if (instance instanceof AggregatedConfiguration) {
ConcurrentMapConfiguration config = new ConcurrentMapConfiguration();
config.loadProperties(props);
((AggregatedConfiguration) instance).addConfiguration(config, configName);
} else {
ConfigurationUtils.loadProperties(props, instance);
}
}
这里可以看到它是调用了loadCascadedProperties(configName)方法加载到了一个java原生的Properties类，然后根据AbstractConfiguration类的具体实现把加载到的配置封装了一下，这里应该不是重点，就不看了，重点关注loadCascadedProperties(configName)方法，继续跟进~
private static Properties loadCascadedProperties(String configName) throws IOException {
String defaultConfigFileName = configName + ".properties";
if (instance == null) {
instance = getConfigInstance();
}
ClassLoader loader = Thread.currentThread().getContextClassLoader();
URL url = loader.getResource(defaultConfigFileName);
if (url == null) {
throw new IOException("Cannot locate " + defaultConfigFileName + " as a classpath resource.");
}
Properties props = getPropertiesFromFile(url);
String environment = getDeploymentContext().getDeploymentEnvironment();
if (environment != null && environment.length() > 0) {
String envConfigFileName = configName + "-" + environment + ".properties";
url = loader.getResource(envConfigFileName);
if (url != null) {
Properties envProps = getPropertiesFromFile(url);
if (envProps != null) {
props.putAll(envProps);
}
}
}
return props;
}
这里可以看到，它是拼接了文件名，然后通过java底层的API去读取了配置文件里面的属性。
那么到这里，整个EurekaServerConfig就创建完毕了~
二、总结
EurekaServerConfig的创建过程也是比较简单的，那还是继续上个图吧~
