com.redhat.coolstore.api_gateway.ApiGatewayApplication.java Source code

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Here is the source code for com.redhat.coolstore.api_gateway.ApiGatewayApplication.java

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/**
 * JBoss, Home of Professional Open Source
 * Copyright 2016, Red Hat, Inc. and/or its affiliates, and individual
 * contributors by the @authors tag. See the copyright.txt in the
 * distribution for a full listing of individual contributors.
 * <p/>
 * 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 com.redhat.coolstore.api_gateway;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.camel.component.servlet.CamelHttpTransportServlet;
import org.apache.camel.spi.RestConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

import org.apache.camel.component.hystrix.metrics.servlet.HystrixEventStreamServlet;

@SpringBootApplication
@Configuration
@ComponentScan
@EnableAutoConfiguration
public class ApiGatewayApplication extends SpringBootServletInitializer {
    private static final String CAMEL_URL_MAPPING = "/api/*";
    private static final String CAMEL_SERVLET_NAME = "CamelServlet";

    public static void main(String[] args) {
        SpringApplication.run(ApiGatewayApplication.class, args);
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(applicationClass);
    }

    @Bean
    public ServletRegistrationBean servletRegistrationBean() {
        ServletRegistrationBean registration = new ServletRegistrationBean(new CORSServlet(), CAMEL_URL_MAPPING);
        registration.setName(CAMEL_SERVLET_NAME);

        return registration;
    }

    @Bean
    public ServletRegistrationBean metricsServlet() {
        ServletRegistrationBean registration = new ServletRegistrationBean(new HystrixEventStreamServlet(),
                "/hystrix.stream");
        return registration;
    }

    private static Class<ApiGatewayApplication> applicationClass = ApiGatewayApplication.class;

    private class CORSServlet extends CamelHttpTransportServlet {
        @Override
        protected void doService(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {

            String authHeader = request.getHeader("Authorization");
            String origin = request.getHeader("Origin");
            if (origin == null || origin.isEmpty()) {
                origin = "*";
            }

            response.setHeader("Access-Control-Allow-Origin", origin);
            response.setHeader("Access-Control-Allow-Methods", RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_METHODS);
            response.setHeader("Access-Control-Allow-Headers",
                    "Authorization, " + RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_HEADERS);
            response.setHeader("Access-Control-Max-Age", RestConfiguration.CORS_ACCESS_CONTROL_MAX_AGE);
            response.setHeader("Access-Control-Allow-Credentials", "true");

            super.doService(request, response);
        }
    }
}