tomcat阅读第十六篇(tomcat Connector)
这篇分析Connector组件，之前第八篇分析StandardService中涉及到Connector，
分析Service的时候，知道StartInternal里面会调用connectors的每个connector的start方法，一个service可以有多个connector，可以从catalina类的digester里面可以看到addConnector的地方，下面是代码片段：
protected Digester createStartDigester() { digester.addRule("Server/Service/Connector", new ConnectorCreateRule()); digester.addRule("Server/Service/Connector", new SetAllPropertiesRule( new String[]{"executor", "sslImplementationName", "protocol"})); digester.addSetNext("Server/Service/Connector", "addConnector", "org.apache.catalina.connector.Connector");
}
前面分析Service的Digester的时候，知道ConnectorCreateRule规则，解析到Connector标签的时候，读取Connector的executor标签属性，从service中获得Executor，读取Connector的protocol标签属性，protocol作为构造方法参数创建Connector，给connector的protocol设置executor，这里也是可以调优的地方。
前面分析rule的时候知道，SetNextRule会调用digester的service. addConnector,下面是StandardService.addConnector代码片段
public void addConnector(Connector connector) { synchronized (connectorsLock) { connector.setService(this); Connector results[] = new Connector[connectors.length + 1]; System.arraycopy(connectors, 0, results, 0, connectors.length); results[connectors.length] = connector; connectors = results; if (getState().isAvailable()) { try { connector.start(); } catch (LifecycleException e) { log.error(sm.getString( "standardService.connector.startFailed", connector), e); } } // Report this property change to interested listeners support.firePropertyChange("connector", null, connector); } }
下面分析创建Connector对象链的，跟之前一样，看Catalian的createStartDigester里面关于Connector的rule配置片段
protected Digester createStartDigester() { …………………….. //解析到Connector标签的时候，读取Connector的executor标签属性，从service 中获得Executor，读取Connector的protocol标签属性，protocol作为构造方法参数创建Connector，给connector的protocol设置executor，这里也是可以调优的地方 digester.addRule("Server/Service/Connector", new ConnectorCreateRule()); //设置Connector标签的属性给Connector对象，除了executor、sslImplementationName和protocol digester.addRule("Server/Service/Connector", new SetAllPropertiesRule( new String[]{"executor", "sslImplementationName", "protocol"})); //调用service的addConnector传入上面rule创建的Connector digester.addSetNext("Server/Service/Connector", "addConnector", "org.apache.catalina.connector.Connector"); //解析到xx/xx/ Connector/SSLHostConfig标签的时候，创建对象SSLHostConfig，push进digester digester.addObjectCreate("Server/Service/Connector/SSLHostConfig", "org.apache.tomcat.util.net.SSLHostConfig"); //解析到xx/xx/ Connector/SSLHostConfig标签的时候，设置标签的属性给ObjectCreateRule创建的SSLHostConfig digester.addSetProperties("Server/Service/Connector/SSLHostConfig"); //同上解析到SSLHostConfig的时候，调用Connector的方法addSslHostConfig，传入SSLHostConfig digester.addSetNext("Server/Service/Connector/SSLHostConfig", "addSslHostConfig", "org.apache.tomcat.util.net.SSLHostConfig"); //解析到xx/xx/ Connector/SSLHostConfig/ Certificate标签的时候，执行CertificateCreateRule，CertificateCreateRule规则是读取Certificate标签的type属性，new SSLHostConfigCertificate(sslHostConfig, type)，push进digester digester.addRule("Server/Service/Connector/SSLHostConfig/Certificate", new CertificateCreateRule()); //同上，设置Certificate标签属性给对象SSLHostConfigCertificate，除了type属性 digester.addRule("Server/Service/Connector/SSLHostConfig/Certificate", new SetAllPropertiesRule(new String[]{"type"})); //同上，解析到Certificate标签的，调用SSLHostConfig的addCertificate方法，传入SSLHostConfigCertificate digester.addSetNext("Server/Service/Connector/SSLHostConfig/Certificate", "addCertificate", "org.apache.tomcat.util.net.SSLHostConfigCertificate"); //解析到xx/xx/ Connector/Listener的时候，创建Listener，className属性必须指定 digester.addObjectCreate("Server/Service/Connector/Listener", null, // MUST be specified in the element "className"); //同上，解析Listener标签的时候，设置Listener标签属性给创建的Listener对象 digester.addSetProperties("Server/Service/Connector/Listener"); //同上，解析Listener标签的时候，调用Connector的addLifecycleListener方法，传入ObjectCreateRule 创建的对象 digester.addSetNext("Server/Service/Connector/Listener", "addLifecycleListener", "org.apache.catalina.LifecycleListener"); //解析到xx/xx/ Connector/UpgradeProtocol，创建className指定的对象，className必须指定 digester.addObjectCreate("Server/Service/Connector/UpgradeProtocol", null, // MUST be specified in the element "className"); //同上，解析到UpgradeProtocol标签的时候，设置UpgradeProtocol标签属性给上面rule创建的对象 digester.addSetProperties("Server/Service/Connector/ UpgradeProtocol "); //同上，解析到UpgradeProtocol标签的时候，调用Connector的addUpgradeProtocol，传入上面rule创建的对象 digester.addSetNext("Server/Service/Connector/UpgradeProtocol", "addUpgradeProtocol", "org.apache.coyote.UpgradeProtocol"); ……………………… }
现在看下Connector类，public class Connector extends LifecycleMBeanBase这是Connector类的签名，可以看出他也是LifeCycle继承链下的组件，这个主要是看Internal系列的方法，先看下类的构造方法
public Connector() { //默认是org.apache.coyote.http11.Http11NioProtocol this("org.apache.coyote.http11.Http11NioProtocol"); } public Connector(String protocol) { boolean aprConnector = AprLifecycleListener.isAprAvailable() && AprLifecycleListener.getUseAprConnector(); // ConnectorCreateRule解析，调用构造方法，传入Connector的protocol标签属性值 if ("HTTP/1.1".equals(protocol) || protocol == null) { if (aprConnector) { protocolHandlerClassName = "org.apache.coyote.http11.Http11AprProtocol"; } else { protocolHandlerClassName = "org.apache.coyote.http11.Http11NioProtocol"; } } else if ("AJP/1.3".equals(protocol)) { if (aprConnector) { protocolHandlerClassName = "org.apache.coyote.ajp.AjpAprProtocol"; } else { protocolHandlerClassName = "org.apache.coyote.ajp.AjpNioProtocol"; } } else { protocolHandlerClassName = protocol; } ProtocolHandler p = null; try { //反射实例化ProtocolHandler之前指定的protocolHandlerClassName，ProtocolHandler实例 Class<?> clazz = Class.forName(protocolHandlerClassName); p = (ProtocolHandler) clazz.newInstance(); } catch (Exception e) { log.error(sm.getString( "coyoteConnector.protocolHandlerInstantiationFailed"), e); } finally { this.protocolHandler = p; } ……………………. }
現在看下Internal方法，initInternal、startInternal、stopInternal和destroyInternal方法
initInternal 方法
protected void initInternal() throws LifecycleException { super.initInternal(); if (protocolHandler == null) { throw new LifecycleException( sm.getString("coyoteConnector.protocolHandlerInstantiationFailed")); } // 实例化CoyoteAdapter对象，当前Connector作为参数，CoyoteAdapter这个类很重要，后面单独篇分析 adapter = new CoyoteAdapter(this); //设置Adapter给protocolHandler protocolHandler.setAdapter(adapter); if (null == parseBodyMethodsSet) { setParseBodyMethods(getParseBodyMethods()); } //如果protocolHandler要求Apr但是Apr不可用话报错 if(protocolHandler.isAprRequired() && !AprLifecycleListener.isAprAvailable()) { throw new LifecycleException(sm.getString("coyoteConnector.protocolHandlerNoApr", getProtocolHandlerClassName())); } //如果Apr可以用并且getUseOpenSSL为true并且protocolHandler是AbstractHttp11JsseProtocol，设置handler的SslImplementationName，参数是OpenSSLImplementation类名 if (AprLifecycleListener.isAprAvailable() && AprLifecycleListener.getUseOpenSSL() && protocolHandler instanceof AbstractHttp11JsseProtocol) { AbstractHttp11JsseProtocol<?> jsseProtocolHandler = (AbstractHttp11JsseProtocol<?>) protocolHandler; if (jsseProtocolHandler.isSSLEnabled() && jsseProtocolHandler.getSslImplementationName() == null) { // OpenSSL is compatible with the JSSE configuration, so use it if APR is available jsseProtocolHandler.setSslImplementationName(OpenSSLImplementation.class.getName()); } } try { //调用handler的init protocolHandler.init(); } catch (Exception e) { throw new LifecycleException( sm.getString("coyoteConnector.protocolHandlerInitializationFailed"), e); } }
其中startInternal、stopInternal和destroyInternal 方法就是protocolHandler对象对应的start、stop和destroy方法的调用
上面CoyoteAdapter类和handler与Connector的对象关系如下图
