StandardEngineValve.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.core;

import java.io.IOException;

import javax.servlet.ServletException;

import org.apache.catalina.Host;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.valves.ValveBase;

/**
 * Valve that implements the default basic behavior for the <code>StandardEngine</code> container implementation.
 * <p>
 * <b>USAGE CONSTRAINT</b>: This implementation is likely to be useful only when processing HTTP requests.
 *
 * @author Craig R. McClanahan
 */
final class StandardEngineValve extends ValveBase {

    // ------------------------------------------------------ Constructor
    StandardEngineValve() {
        super(true);
    }


    // --------------------------------------------------------- Public Methods

    /**
     * Select the appropriate child Host to process this request, based on the requested server name. If no matching
     * Host can be found, return an appropriate HTTP error.
     *
     * @param request  Request to be processed
     * @param response Response to be produced
     *
     * @exception IOException      if an input/output error occurred
     * @exception ServletException if a servlet error occurred
     */
    @Override
    public void invoke(Request request, Response response) throws IOException, ServletException {

        // Select the Host to be used for this Request
        Host host = request.getHost();
        if (host == null) {
            // HTTP 0.9 or HTTP 1.0 request without a host when no default host
            // is defined.
            // Don't overwrite an existing error
            if (!response.isError()) {
                response.sendError(404);
            }
            return;
        }
        if (request.isAsyncSupported()) {
            request.setAsyncSupported(host.getPipeline().isAsyncSupported());
        }

        // Ask this Host to process this request
        host.getPipeline().getFirst().invoke(request, response);
    }
}