tomcat源码阅读_代码篇9

在上文中，看到在connector类中，是启动、初始化、停止、恢复protocolHandler对象，而该对象的类型是ProtocolHandler，它属于org.apache.coyote 包。

该接口签名如下public interface ProtocolHandler，是协议的抽象，包括线程的。Processor是单线程的基于流的协议，不适用于类似于JNI的JK协议。它是coyote连接器实现的主要接口，Adaper是coyote Servlet容器实现的主要接口。~~~文档太烂了！！！

原文：

Abstract the protocol implementation, including threading, etc. Processor is single threaded and specific to stream-based protocols, will not fit Jk protocols like JNI. This is the main interface to be implemented by a coyoute connector. Adapter is the main interface to be impleneted by a coyote servlet container

实现了改接口的类有：

AjpAprProtocol, AjpProtocol, Http11AprProtocol, Http11NioProtocol, Http11Protocol, JkCoyoteHandler, MemoryProtocolHandler

主要是各种协议的处理。首先看Http11Protocol，该类属于org.apache.coyote.http11 包。

该类的签名如下

public class Http11Protocol   implements ProtocolHandler, MBeanRegistration

init方法：

public void init() throws Exception {
        endpoint.setName(getName());
        endpoint.setHandler(cHandler);

        // Verify the validity of the configured socket factory
        try {
            if (isSSLEnabled()) {
                sslImplementation =
                    SSLImplementation.getInstance(sslImplementationName);//SSLImplementation是抽象类，会返回JSSEImplementation实例
                socketFactory = sslImplementation.getServerSocketFactory();
                endpoint.setServerSocketFactory(socketFactory);
            } else if (socketFactoryName != null) {
                socketFactory = (ServerSocketFactory) Class.forName(socketFactoryName).newInstance();
                endpoint.setServerSocketFactory(socketFactory);
            }
        } catch (Exception ex) {
            log.error(sm.getString("http11protocol.socketfactory.initerror"),
                      ex);
            throw ex;
        }

        if (socketFactory!=null) {//设置socketFactory工厂的属性
            Iterator<String> attE = attributes.keySet().iterator();
            while( attE.hasNext() ) {
                String key = attE.next();
                Object v=attributes.get(key);
                socketFactory.setAttribute(key, v);
            }
        }
       
        try {
            endpoint.init();//初始化endpoint
        } catch (Exception ex) {
            log.error(sm.getString("http11protocol.endpoint.initerror"), ex);
            throw ex;
        }
        if (log.isInfoEnabled())
            log.info(sm.getString("http11protocol.init", getName()));

    }

endpoint对象是JIoEndpoint的实例，该类 实现一个简单的服务器模型：一个线程监听套接字并为每个传入的连接创建一个新的工作线程。

cHandler是Http11ConnectionHandler类的对象，该类是Http11Protocol的内部类。

sslImplementation.getServerSocketFactory();
会调用

public ServerSocketFactory getServerSocketFactory() {
        ServerSocketFactory ssf = factory.getSocketFactory();
        return ssf;
    }

而factory是JSSEFactory的对象。返回一个JSSESocketFactory类型的工厂，由该类负责创建socket的工作，关于该类下面再进行介绍。

否则根据socketFactoryName加载ServerSocketFactory类型的工厂。

初始化endpoint的时候回调用：

    public void init()
        throws Exception {

        if (initialized)
            return;
       
        // Initialize thread count defaults for acceptor
        if (acceptorThreadCount == 0) {
            acceptorThreadCount = 1;
        }
        if (serverSocketFactory == null) {
            serverSocketFactory = ServerSocketFactory.getDefault();
        }
        if (serverSocket == null) {
            try {
                if (address == null) {
                    serverSocket = serverSocketFactory.createSocket(port, backlog);
                } else {
                    serverSocket = serverSocketFactory.createSocket(port, backlog, address);
                }
            } catch (BindException be) {
                if (address == null)
                    throw new BindException(be.getMessage() + "<null>:" + port);
                else
                    throw new BindException(be.getMessage() + " " +
                            address.toString() + ":" + port);
            }
        }
        //if( serverTimeout >= 0 )
        //    serverSocket.setSoTimeout( serverTimeout );
       
        initialized = true;
       
    }

该方法主要负责初始化一个serversocket。

此后的start、rusume、stop方法都是针对endpoint来执行的。

另外在Http11Protocol类中还有一个静态内部类：

protected static class Http11ConnectionHandler implements Handler

该类的主要方法是process用来处理接受到得socket，处理socket的是Http11Processor类的对象，在Http11ConnectionHandler 中维持了一个ConcurrentLinkedQueue来持有Http11Processor对象。每次处理的时候，从队列中取出一个Http11Processor对象来处理请求，如果队列为空，则使用createProcessor方法创建，处理完成后将Http11Processor对象添加到队列中。

在下一小节中，主要对JIoEndpoint以及Http11Processor进行介绍。