tomcat 源码分析之service

service类提供服务的，可以配置多个它的初始化方法
@Override
    protected void initInternal() throws LifecycleException {

        super.initInternal();
        
        if (container != null) {
            container.init();
        }

        // Initialize any Executors
        for (Executor executor : findExecutors()) {
            if (executor instanceof LifecycleMBeanBase) {
                ((LifecycleMBeanBase) executor).setDomain(getDomain());
            }
            executor.init();
        }

        // Initialize our defined Connectors
        synchronized (connectors) {
            for (Connector connector : connectors) {
                try {
                    connector.init();
                } catch (Exception e) {
                    String message = sm.getString(
                            "standardService.connector.initFailed", connector);
                    log.error(message, e);

                    if (Boolean.getBoolean("org.apache.catalina.startup.EXIT_ON_INIT_FAILURE"))
                        throw new LifecycleException(message);
                }
            }
        }
    }

从上面我们看到service包含多个Executor和connector，connection接受客户的请求然后交给executor处理

Executor的默认实现是StandardThreadExecutor

@Override
    protected void startInternal() throws LifecycleException {

        taskqueue = new TaskQueue(maxQueueSize);
        TaskThreadFactory tf = new TaskThreadFactory(namePrefix,daemon,getThreadPriority());
        executor = new ThreadPoolExecutor(getMinSpareThreads(), getMaxThreads(), maxIdleTime, TimeUnit.MILLISECONDS,taskqueue, tf);
        executor.setThreadRenewalDelay(threadRenewalDelay);
        if (prestartminSpareThreads) {
            executor.prestartAllCoreThreads();
        }
        taskqueue.setParent(executor);

        setState(LifecycleState.STARTING);
    }

 从上面我们看到其实是创建一个线程池由他负责处理请求。

下面是Connector的的构造方法

public Connector(String protocol) {
        setProtocol(protocol);
        // 初始化协议处理类默认是org.apache.coyote.http11.Http11Protocol
        try {
            Class<?> clazz = Class.forName(protocolHandlerClassName);
            this.protocolHandler = (ProtocolHandler) clazz.newInstance();
        } catch (Exception e) {
            log.error(sm.getString(
                    "coyoteConnector.protocolHandlerInstantiationFailed"), e);
        }
    }

下面是他的初始化方法
 @Override
    protected void initInternal() throws LifecycleException {

        super.initInternal();
         //请求响应对象从连接器传送到容器需要一个桥梁
        adapter = new CoyoteAdapter(this);
        protocolHandler.setAdapter(adapter);
        if( null == parseBodyMethodsSet ) {
            setParseBodyMethods(getParseBodyMethods());
        }

        if (protocolHandler.isAprRequired() &&
                !AprLifecycleListener.isAprAvailable()) {
            throw new LifecycleException(
                    sm.getString("coyoteConnector.protocolHandlerNoApr",
                            getProtocolHandlerClassName()));
        }

        try {
            protocolHandler.init();
        } catch (Exception e) {
            throw new LifecycleException
                (sm.getString
                 ("coyoteConnector.protocolHandlerInitializationFailed"), e);
        }

        // Initialize mapper listener
        mapperListener.init();
    }