AsyncAppender继承了AsyncAppenderBase，它新增了includeCallerData配置，另外覆盖了isDiscardable、preprocess方法，isDiscardable针对TRACE、DEBUG的级别返回true，INFO返回false；preprocess则判断是否includeCallerData，是的话则执行eventObject.getCallerData()

org/springframework/boot/actuate/autoconfigure/metrics/web/tomcat/TomcatMetricsAutoConfiguration.java

序本文主要研究一下HttpClient的closeCloseableHttpClientorg/apache/http/impl/client/CloseableHttpClient.java {代码...} CloseableHttpClient声明实现HttpClient, Closeable接口InternalHttpClientorg/apache/http/impl/client/InternalHttpClient.java {代码...} InternalHttpClient继承了CloseableHttpClient，其...

这里取了maxIdle配置来进行预热，通过DirectFieldAccessor来获取jedisConnectionFactory对象的pool

org/springframework/boot/autoconfigure/availability/ApplicationAvailabilityAutoConfiguration.java

序本文主要研究一下线程池的预热prestartCoreThreadjava/util/concurrent/ThreadPoolExecutor.java {代码...} ThreadPoolExecutor定义了prestartCoreThread，用于启动一个核心线程prestartAllCoreThreadsjava/util/concurrent/ThreadPoolExecutor.java {代码...} prestartAllCoreThreads用于启动所有的核心线程小结Threa...

org/springframework/kafka/annotation/KafkaListenerAnnotationBeanPostProcessor.java

实现了RocketMQListener接口的类，再配合@RocketMQMessageListener注解就可以实现对rocketmq消息的消费

spring-beans/src/main/java/org/springframework/beans/factory/DisposableBean.java

spring-beans/src/main/java/org/springframework/beans/factory/annotation/InitDestroyAnnotationBeanPostProcessor.java

RedirectStrategy接口定义了isRedirected方法用于判断是否需要redirect，还定义了getRedirect方法用于返回redirect的目标地址

序本文主要研究一下HttpClient的DnsResolverDnsResolverorg/apache/http/conn/DnsResolver.java {代码...} DnsResolver定义了resolve方法，可用于替换OS提供的DNS lookupInMemoryDnsResolverorg/apache/http/impl/conn/InMemoryDnsResolver.java {代码...} InMemoryDnsResolver实现了DnsResolver接口，它用一个Concurren...

序本文主要研究一下HttpClient的HttpRoutePlannerHttpRoutePlannerorg/apache/http/conn/routing/HttpRoutePlanner.java {代码...} HttpRoutePlanner接口定义了determineRoute方法，用于决定该请求的目标routeDefaultRoutePlannerorg/apache/http/impl/conn/DefaultRoutePlanner.java {代码...} DefaultRoutePlanner实现...

BackoffManager接口主要用于根据connection的情况来动态调整连接池的connection大小，它定义了backOff方法用于缩小连接数，probe方法用于扩大连接数

序本文主要研究一下HttpClient的ConnectionBackoffStrategyConnectionBackoffStrategyorg/apache/http/client/ConnectionBackoffStrategy.java {代码...} ConnectionBackoffStrategy定义了shouldBackoff方法，它根据异常或者response来进行判断NullBackoffStrategyorg/apache/http/impl/client/NullBackoffStrategy.java...

ServiceUnavailableRetryStrategy定义了retryRequest方法用于返回是否该重试，getRetryInterval返回自动重试的间隔

HttpRequestRetryHandler接口定义了retryRequest方法，它接收IOException、executionCount及context，然后判断是否可以重试

序本文主要研究一下HttpClient的NoHttpResponseExceptionNoHttpResponseExceptionorg/apache/http/NoHttpResponseException.java {代码...} NoHttpResponseException继承了IOException，用于表示目标服务器没有返回一个正常的http responseDefaultHttpResponseParserorg/apache/http/impl/conn/DefaultHttpResponseParse...

ConnectionKeepAliveStrategy接口定义了getKeepAliveDuration方法，用于返回该connection空间多久以内被复用是安全的

序本文主要研究一下HttpClient的ResponseHandlerResponseHandlerorg/apache/http/client/ResponseHandler.java {代码...} ResponseHandler定义了handleResponse方法，用于解析HttpResponse到泛型TAbstractResponseHandlerorg/apache/http/impl/client/AbstractResponseHandler.java {代码...} AbstractResponseHandler声...

org/springframework/http/client/HttpComponentsClientHttpRequestFactory.java

micrometer-core-1.3.0-sources.jar!/io/micrometer/core/instrument/binder/httpcomponents/MicrometerHttpRequestExecutor.java

HttpClientBuilder提供了evictExpiredConnections方法，该方法会设置evictExpiredConnections为true

序本文主要研究一下httpclient的CPoolConnPoolorg/apache/http/pool/ConnPool.java {代码...} ConnPool定义了lease及release方法，其中定义了两个泛型，T表示route，E表示poolEntryConnPoolControl {代码...} ConnPoolControl接口定义了设置和访问maxTotal、defaultMaxPerRoute及PoolStats的方法AbstractConnPoolorg/apa...

httpclient-4.5.10-sources.jar!/org/apache/http/impl/client/HttpClientBuilder.java

org/springframework/remoting/httpinvoker/HttpComponentsHttpInvokerRequestExecutor.java

druid-1.2.11-sources.jar!/com/alibaba/druid/pool/DruidPooledConnection.java

DruidDataSource的init方法在keepAlive的时候触发创建连接，当createScheduler不为null时(默认为null)执行submitCreateTask，否则执行emptySignal

DruidDataSource的init方法会执行createAndStartDestroyThread；而createAndStartDestroyThread在destroyScheduler不为null的时候会定时(timeBetweenEvictionRunsMillis)调度destroyTask，不过destroyScheduler默认为null；同时它还启动了DestroyConnectionThread

序本文主要研究一下druid连接池的监控initcom/alibaba/druid/pool/DruidDataSource.java {代码...} DruidDataSource的init方法会执行registerMbeanregisterMbeancom/alibaba/druid/pool/DruidDataSource.java {代码...} registerMbean会执行DruidDataSourceStatManager.addDataSource(DruidDataSource.this, DruidDataSo...