然后我发送一个 http://localhost:8088/coffee的请求
package org.apache.catalina.connector; public class CoyoteAdapter implements Adapter { public void service(org.apache.coyote.Request req, org.apache.coyote.Response res) Request request = (Request) req.getNote(ADAPTER_NOTES); Response response = (Response) res.getNote(ADAPTER_NOTES); ..... 这个CoyoteAdapter的方法service会接收这个http请求然后看一下这个req的状态
然后看一下request对象 ，相对于req request多了一些mappingData字段
其中对应的请求 /coffee 到底会分发到哪个Servelt ，将最终取决于 mappingData是什么
接下来继续看代码。。
try { // Parse and set Catalina and configuration specific // request parameters req.getRequestProcessor().setWorkerThreadName(THREAD_NAME.get()); postParseSuccess = postParseRequest(req, request, res, response); if (postParseSuccess) { //check valves if we support async request.setAsyncSupported(connector.getService().getContainer().getPipeline().isAsyncSupported()); // Calling the container connector.getService().getContainer().getPipeline().getFirst().invoke(request, response); } 接着看 postParseRequest ， 方法中有下面一段 // Version for the second mapping loop and // Context that we expect to get for that version String version = null; Context versionContext = null; boolean mapRequired = true; while (mapRequired) { // This will map the the latest version by default connector.getService().getMapper().map(serverName, decodedURI, version, request.getMappingData());接着看一下 package org.apache.catalina.mapper; public final class Mapper { /** * Map the specified host name and URI, mutating the given mapping data. * * @param host Virtual host name * @param uri URI * @param version The version, if any, included in the request to be mapped * @param mappingData This structure will contain the result of the mapping * operation * @throws IOException if the buffers are too small to hold the results of * the mapping. */ public void map(MessageBytes host, MessageBytes uri, String version, MappingData mappingData) throws IOException { if (host.isNull()) { host.getCharChunk().append(defaultHostName); } host.toChars(); uri.toChars(); internalMap(host.getCharChunk(), uri.getCharChunk(), version, mappingData); } /** * Map the specified URI. * @throws IOException */ private final void internalMap(CharChunk host, CharChunk uri, String version, MappingData mappingData) throws IOException {然后看一下、方法的结尾有这么一段
if (contextVersion == null) { // Return the latest version // The versions array is known to contain at least one element contextVersion = contextVersions[versionCount - 1]; } mappingData.context = contextVersion.object; mappingData.contextSlashCount = contextVersion.slashCount; // Wrapper mapping if (!contextVersion.isPaused()) { internalMapWrapper(contextVersion, uri, mappingData); }接着看一下 InternalMapWrapper
接着看源码
// Rule 1 -- Exact Match MappedWrapper[] exactWrappers = contextVersion.exactWrappers; internalMapExactWrapper(exactWrappers, path, mappingData); // Rule 2 -- Prefix Match boolean checkJspWelcomeFiles = false; MappedWrapper[] wildcardWrappers = contextVersion.wildcardWrappers; 先从extraWrappers 中查找，然后从 jsp 或者 welcome wrappers中找最后是DefaultServlet
/** * Exact mapping. */ private final void internalMapExactWrapper (MappedWrapper[] wrappers, CharChunk path, MappingData mappingData) { MappedWrapper wrapper = exactFind(wrappers, path); if (wrapper != null) { mappingData.requestPath.setString(wrapper.name); mappingData.wrapper = wrapper.object; if (path.equals("/")) { // Special handling for Context Root mapped servlet mappingData.pathInfo.setString("/"); mappingData.wrapperPath.setString(""); // This seems wrong but it is what the spec says... mappingData.contextPath.setString(""); mappingData.matchType = MappingMatch.CONTEXT_ROOT; } else { mappingData.wrapperPath.setString(wrapper.name); mappingData.matchType = MappingMatch.EXACT; } } }
然后执行完了 、递归 回到
CoyoteAdapter # service 中
然后
connector.getService().getContainer().getPipeline().getFirst().invoke(request, response); 一直会执行到 package org.apache.catalina.core; final class StandardWrapperValve extends ValveBase { @Override public final void invoke(Request request, Response response) throws IOException, ServletException { try {// 创建servlet对象 if (!unavailable) { servlet = wrapper.allocate(); } } 。。。。。。。。。 if ((servlet != null) && (filterChain != null)) { // Swallow output if needed if (context.getSwallowOutput()) { try { SystemLogHandler.startCapture(); if (request.isAsyncDispatching()) { request.getAsyncContextInternal().doInternalDispatch(); } else { filterChain.doFilter(request.getRequest(), response.getResponse()); } } finally { String log = SystemLogHandler.stopCapture(); if (log != null && log.length() > 0) { context.getLogger().info(log); } } } else { if (request.isAsyncDispatching()) { request.getAsyncContextInternal().doInternalDispatch(); } else { filterChain.doFilter (request.getRequest(), response.getResponse()); } } }然后在继续往下跟踪代码
org.apache.catalina.core; final class ApplicationFilterChain implements FilterChain { private void internalDoFilter(ServletRequest request, ServletResponse response) 方法中有如下代码 try { if (ApplicationDispatcher.WRAP_SAME_OBJECT) { lastServicedRequest.set(request); lastServicedResponse.set(response); } if (request.isAsyncSupported() && !servletSupportsAsync) { request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, Boolean.FALSE); } // Use potentially wrapped request from this point if ((request instanceof HttpServletRequest) && (response instanceof HttpServletResponse) && Globals.IS_SECURITY_ENABLED ) { final ServletRequest req = request; final ServletResponse res = response; Principal principal = ((HttpServletRequest) req).getUserPrincipal(); Object[] args = new Object[]{req, res}; SecurityUtil.doAsPrivilege("service", servlet, classTypeUsedInService, args, principal); } else { servlet.service(request, response); }最终分发到相应的Servlet
