io.servicecomb.springboot.starter.transport.RestServletInitializer Maven / Gradle / Ivy

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/*
 * Copyright 2017 Huawei Technologies Co., Ltd
 *
 * Licensed 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 io.servicecomb.springboot.starter.transport;

import java.io.IOException;
import java.net.ServerSocket;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.context.embedded.AbstractConfigurableEmbeddedServletContainer;
import org.springframework.boot.web.servlet.ServletContextInitializer;
import org.springframework.stereotype.Component;

import io.servicecomb.transport.rest.servlet.RestServletInjector;

@Component
// extends from AbstractConfigurableEmbeddedServletContainer, only want to get embed web container's port and address
// when org.springframework.web.context.ServletContextAware invoked, ServletContext already rejected to addServlet
// should implements org.springframework.boot.web.servlet.ServletContextInitializer to inject servlet
public class RestServletInitializer extends AbstractConfigurableEmbeddedServletContainer
        implements ServletContextInitializer {
    private static final Logger LOGGER = LoggerFactory.getLogger(RestServletInitializer.class);

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        if (getPort() == 0) {
            LOGGER.warn(
                    "spring boot embed web container listen port is 0, serviceComb will not use container's port to handler RESTful request.");
            return;
        }

        // web container did not did listen now.
        // so mock to listen, and then close.
        try (ServerSocket ss = new ServerSocket(getPort(), 0, getAddress())) {
            RestServletInjector.defaultInject(servletContext);
        } catch (IOException e) {
            throw new ServletException(e);
        }
    }
}