Tomcat处理http请求之源码分析

protected class Acceptor extends AbstractEndpoint.Acceptor {
    @Override
    public void run() {
        while (running) {
            ……
            try {
                //当前连接数
                countUpOrAwaitConnection();
                Socket socket = null;
                try {
                    //取出队列中的连接请求
                    socket = serverSocketFactory.acceptSocket(serverSocket);
                } catch (IOException ioe) {
                    countDownConnection();
                }
                if (running && !paused && setSocketOptions(socket)) {
                    //处理请求
                    if (!processSocket(socket)) {
                        countDownConnection();
                        closeSocket(socket);
                    }
                } else {
                    countDownConnection();
                    // Close socket right away
                    closeSocket(socket);
                }
            } 
            ……
        }
    }
}

protected boolean processSocket(Socket socket) {
    try {
        SocketWrapper<Socket> wrapper = new SocketWrapper<Socket>(socket);
        wrapper.setKeepAliveLeft(getMaxKeepAliveRequests());
        wrapper.setSecure(isSSLEnabled());
        //交给线程池处理连接
        getExecutor().execute(new SocketProcessor(wrapper));
    } 
    ……
    return true;
}

protected class SocketProcessor implements Runnable {
    protected SocketWrapper<Socket> socket = null;
    protected SocketStatus status = null;
    @Override
    public void run() {
        boolean launch = false;
        synchronized (socket) {
            SocketState state = SocketState.OPEN;
            try {
                serverSocketFactory.handshake(socket.getSocket());
            } 
            ……
            if ((state != SocketState.CLOSED)) {
                //委派给Handler来处理
                if (status == null) {
                    state = handler.process(socket, SocketStatus.OPEN_READ);
                } else {
                    state = handler.process(socket,status);
                }
            }}}
            ……
}

public SocketState process(SocketWrapper socketWrapper) {
    RequestInfo rp = request.getRequestProcessor();
    rp.setStage(org.apache.coyote.Constants.STAGE_PARSE);
    // Setting up the I/O
    setSocketWrapper(socketWrapper);
    getInputBuffer().init(socketWrapper, endpoint);
    getOutputBuffer().init(socketWrapper, endpoint);
    while (!getErrorState().isError() && keepAlive && !comet && !isAsync() &&
            upgradeInbound == null &&
            httpUpgradeHandler == null && !endpoint.isPaused()) {
        ……
        if (!getErrorState().isError()) {
            // Setting up filters, and parse some request headers
            rp.setStage(org.apache.coyote.Constants.STAGE_PREPARE);
            try {
                //请求预处理
                prepareRequest();
            } 
            ……
        }
        ……
        if (!getErrorState().isError()) {
            try {
                rp.setStage(org.apache.coyote.Constants.STAGE_SERVICE);
                //交由适配器处理
                adapter.service(request, response);
                if(keepAlive && !getErrorState().isError() && (
                        response.getErrorException() != null ||
                                (!isAsync() &&
                                statusDropsConnection(response.getStatus())))) {
                    setErrorState(ErrorState.CLOSE_CLEAN, null);
                }
                setCometTimeouts(socketWrapper);
            } 
        }
    }
    ……
}          

public void service(org.apache.coyote.Request req,
                        org.apache.coyote.Response res) {
    ……
    postParseSuccess = postParseRequest(req, request, res, response);
    ……
    connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);
    ……
}

connector.getMapper().map(serverName, decodedURI, version,
                                      request.getMappingData());
request.setContext((Context) request.getMappingData().context);
request.setWrapper((Wrapper) request.getMappingData().wrapper);

public void startInternal() throws LifecycleException {
    setState(LifecycleState.STARTING);
    findDefaultHost();
    Engine engine = (Engine) connector.getService().getContainer();
    addListeners(engine);
    Container[] conHosts = engine.findChildren();
    for (Container conHost : conHosts) {
        Host host = (Host) conHost;
        if (!LifecycleState.NEW.equals(host.getState())) {
            registerHost(host);
        }
    }
}