Java tutorial
/** * 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 com.redhat.coolstore.api_gateway.model.Product; import com.redhat.coolstore.api_gateway.model.Review; import org.apache.camel.Exchange; import org.apache.camel.builder.RouteBuilder; import org.apache.camel.component.http4.HttpMethods; import org.apache.camel.component.jackson.JacksonDataFormat; import org.apache.camel.component.jackson.ListJacksonDataFormat; import org.apache.camel.model.dataformat.JsonLibrary; import org.apache.camel.model.rest.RestBindingMode; import org.apache.camel.model.rest.RestParamType; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.http.MediaType; import org.springframework.stereotype.Component; import java.util.Collections; import java.util.List; @Component public class ReviewGateway extends RouteBuilder { private static final Logger LOG = LoggerFactory.getLogger(ReviewGateway.class); @Value("${hystrix.executionTimeout}") private int hystrixExecutionTimeout; @Value("${hystrix.groupKey}") private String hystrixGroupKey; @Value("${hystrix.circuitBreakerEnabled}") private boolean hystrixCircuitBreakerEnabled; @Autowired private Environment env; @Override public void configure() throws Exception { try { getContext().setTracing(Boolean.parseBoolean(env.getProperty("ENABLE_TRACER", "false"))); } catch (Exception e) { LOG.error("Failed to parse the ENABLE_TRACER value: {}", env.getProperty("ENABLE_TRACER", "false")); } restConfiguration().component("servlet").bindingMode(RestBindingMode.auto).apiContextPath("/api-docs") .contextPath("/api").apiProperty("host", "") .apiProperty("api.title", "CoolStore Microservice Review API Gateway") .apiProperty("api.version", "1.0.0") .apiProperty("api.description", "The API of the gateway which fronts the various backend microservices in the CoolStore") .apiProperty("api.contact.name", "Red Hat Developers") .apiProperty("api.contact.email", "developers@redhat.com") .apiProperty("api.contact.url", "https://developers.redhat.com"); JacksonDataFormat reviewFormatter = new ListJacksonDataFormat(); reviewFormatter.setUnmarshalType(Review.class); rest("/review").description("Product Review Service").produces(MediaType.APPLICATION_JSON_VALUE) .get("/{itemId}").description("Get Product Reviews").param().name("itemId").type(RestParamType.path) .description("The ID of the item to process").dataType("string").endParam().outType(Review.class) .route().id("getReviewRoute").hystrix().id("Review Service (Get Review for Product)") .hystrixConfiguration().executionTimeoutInMilliseconds(hystrixExecutionTimeout) .groupKey(hystrixGroupKey).circuitBreakerEnabled(hystrixCircuitBreakerEnabled).end() .removeHeaders("CamelHttp*").setBody(simple("null")) .setHeader(Exchange.HTTP_METHOD, HttpMethods.GET) .setHeader(Exchange.HTTP_URI, simple("http://{{env:REVIEW_ENDPOINT:review:8080}}/api/review/${header.itemId}")) .to("http4://DUMMY").onFallback().setHeader(Exchange.CONTENT_TYPE, constant("application/json")) .to("direct:getReviewFallback").end() .setHeader("CamelJacksonUnmarshalType", simple(Review.class.getName())).unmarshal(reviewFormatter) .endRest(); // Provide a response from("direct:getReviewFallback").routeId("getreviewfallback").description("Get Review Fall back response") .process(exchange -> exchange.getIn().setBody(Collections.singletonList(new Review()))).marshal() .json(JsonLibrary.Jackson); } }