components/camel-swagger-java/src/main/java/org/apache/camel/swagger/RestSwaggerSupport.java - camel - Git at Google

 /*
  * 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.camel.swagger;

 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 import java.lang.management.ManagementFactory;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;

 import javax.management.AttributeNotFoundException;
 import javax.management.MBeanServer;
 import javax.management.ObjectName;

 import org.w3c.dom.Document;

 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import io.swagger.jaxrs.config.BeanConfig;
 import io.swagger.models.Contact;
 import io.swagger.models.Info;
 import io.swagger.models.License;
 import io.swagger.models.Scheme;
 import io.swagger.models.Swagger;
 import io.swagger.util.Json;
 import io.swagger.util.Yaml;
 import org.apache.camel.CamelContext;
 import org.apache.camel.Exchange;
 import org.apache.camel.model.Model;
 import org.apache.camel.model.ModelHelper;
 import org.apache.camel.model.rest.RestDefinition;
 import org.apache.camel.model.rest.RestsDefinition;
 import org.apache.camel.spi.ClassResolver;
 import org.apache.camel.spi.RestConfiguration;
 import org.apache.camel.support.PatternHelper;
 import org.apache.camel.util.CamelVersionHelper;
 import org.apache.camel.util.ObjectHelper;
 import org.apache.camel.util.URISupport;
 import org.apache.camel.util.xml.XmlLineNumberParser;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import static org.apache.camel.swagger.SwaggerHelper.clearVendorExtensions;

 /**
  * A support class for that allows SPI to plugin
  * and offer Swagger API service listings as part of the Camel component. This allows rest-dsl components
  * such as servlet/jetty/netty-http to offer Swagger API listings with minimal effort.
  */
 public class RestSwaggerSupport {

     static final String HEADER_X_FORWARDED_PREFIX = "X-Forwarded-Prefix";
     static final String HEADER_X_FORWARDED_HOST = "X-Forwarded-Host";
     static final String HEADER_X_FORWARDED_PROTO = "X-Forwarded-Proto";
     static final String HEADER_HOST = "Host";

     private static final Logger LOG = LoggerFactory.getLogger(RestSwaggerSupport.class);
     private RestSwaggerReader reader = new RestSwaggerReader();
     private boolean cors;

     public void initSwagger(BeanConfig swaggerConfig, Map<String, Object> config) {
         // configure swagger options
         String s = (String) config.get("swagger.version");
         if (s != null) {
             swaggerConfig.setVersion(s);
         }
         s = (String) config.get("base.path");
         if (s != null) {
             swaggerConfig.setBasePath(s);
         }
         s = (String) config.get("host");
         if (s != null) {
             swaggerConfig.setHost(s);
         }
         s = (String) config.get("cors");
         if (s != null) {
             cors = "true".equalsIgnoreCase(s);
         }
         s = (String) config.get("schemes");
         if (s == null) {
             // deprecated due typo
             s = (String) config.get("schemas");
         }
         if (s != null) {
             String[] schemes = s.split(",");
             swaggerConfig.setSchemes(schemes);
         } else {
             // assume http by default
             swaggerConfig.setSchemes(new String[]{"http"});
         }

         String version = (String) config.get("api.version");
         String title = (String) config.get("api.title");
         String description = (String) config.get("api.description");
         String termsOfService = (String) config.get("api.termsOfService");
         String licenseName = (String) config.get("api.license.name");
         String licenseUrl = (String) config.get("api.license.url");
         String contactName = (String) config.get("api.contact.name");
         String contactUrl = (String) config.get("api.contact.url");
         String contactEmail = (String) config.get("api.contact.email");

         Info info = new Info();
         info.setVersion(version);
         info.setTitle(title);
         info.setDescription(description);
         info.setTermsOfService(termsOfService);

         if (licenseName != null || licenseUrl != null) {
             License license = new License();
             license.setName(licenseName);
             license.setUrl(licenseUrl);
             info.setLicense(license);
         }

         if (contactName != null || contactUrl != null || contactEmail != null) {
             Contact contact = new Contact();
             contact.setName(contactName);
             contact.setUrl(contactUrl);
             contact.setEmail(contactEmail);
             info.setContact(contact);
         }

         swaggerConfig.setInfo(info);
     }

     public List<RestDefinition> getRestDefinitions(CamelContext camelContext) throws Exception {
         Model model = camelContext.getExtension(Model.class);
         List<RestDefinition> rests = model.getRestDefinitions();
         if (rests.isEmpty()) {
             return null;
         }

         // use a routes definition to dump the rests
         RestsDefinition def = new RestsDefinition();
         def.setRests(rests);
         String xml = ModelHelper.dumpModelAsXml(camelContext, def);

         // if resolving placeholders we parse the xml, and resolve the property placeholders during parsing
         final AtomicBoolean changed = new AtomicBoolean();
         InputStream is = new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8));
         Document dom = XmlLineNumberParser.parseXml(is, new XmlLineNumberParser.XmlTextTransformer() {
             @Override
             public String transform(String text) {
                 try {
                     String after = camelContext.resolvePropertyPlaceholders(text);
                     if (!changed.get()) {
                         changed.set(!text.equals(after));
                     }
                     return after;
                 } catch (Exception e) {
                     // ignore
                     return text;
                 }
             }
         });
         // okay there were some property placeholder replaced so re-create the model
         if (changed.get()) {
             xml = camelContext.getTypeConverter().mandatoryConvertTo(String.class, dom);
             def = ModelHelper.createModelFromXml(camelContext, xml, RestsDefinition.class);
             if (def != null) {
                 return def.getRests();
             }
         }

         return rests;
     }

     public List<RestDefinition> getRestDefinitions(String camelId) throws Exception {
         ObjectName found = null;
         boolean supportResolvePlaceholder = false;

         MBeanServer server = ManagementFactory.getPlatformMBeanServer();
         Set<ObjectName> names = server.queryNames(new ObjectName("org.apache.camel:type=context,*"), null);
         for (ObjectName on : names) {
             String id = on.getKeyProperty("name");
             if (id.startsWith("\"") && id.endsWith("\"")) {
                 id = id.substring(1, id.length() - 1);
             }
             if (camelId == null || camelId.equals(id)) {
                 // filter out older Camel versions as this requires Camel 2.15 or better (rest-dsl)
                 String version = (String) server.getAttribute(on, "CamelVersion");
                 if (CamelVersionHelper.isGE("2.15.0", version)) {
                     found = on;
                 }
                 if (CamelVersionHelper.isGE("2.15.3", version)) {
                     supportResolvePlaceholder = true;
                 }
             }
         }

         if (found != null) {
             String xml;
             if (supportResolvePlaceholder) {
                 xml = (String) server.invoke(found, "dumpRestsAsXml", new Object[]{true}, new String[]{"boolean"});
             } else {
                 xml = (String) server.invoke(found, "dumpRestsAsXml", null, null);
             }
             if (xml != null) {
                 LOG.debug("DumpRestAsXml:\n{}", xml);
                 RestsDefinition rests = ModelHelper.createModelFromXml(null, xml, RestsDefinition.class);
                 if (rests != null) {
                     return rests.getRests();
                 }
             }
         }

         return null;
     }

     public List<String> findCamelContexts() throws Exception {
         List<String> answer = new ArrayList<>();

         MBeanServer server = ManagementFactory.getPlatformMBeanServer();
         Set<ObjectName> names = server.queryNames(new ObjectName("*:type=context,*"), null);
         for (ObjectName on : names) {

             String id = on.getKeyProperty("name");
             if (id.startsWith("\"") && id.endsWith("\"")) {
                 id = id.substring(1, id.length() - 1);
             }

             // filter out older Camel versions as this requires Camel 2.15 or better (rest-dsl)
             try {
                 String version = (String) server.getAttribute(on, "CamelVersion");
                 if (CamelVersionHelper.isGE("2.15.0", version)) {
                     answer.add(id);
                 }
             } catch (AttributeNotFoundException ex) {
                 // ignore
             }
         }
         return answer;
     }

     public void renderResourceListing(CamelContext camelContext, RestApiResponseAdapter response, BeanConfig swaggerConfig, String contextId, String route, boolean json, boolean yaml,
                                       Map<String, Object> headers, ClassResolver classResolver, RestConfiguration configuration) throws Exception {
         LOG.trace("renderResourceListing");

         ObjectMapper mapper = Json.mapper();
         mapper.enable(SerializationFeature.INDENT_OUTPUT);
         mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

         if (cors) {
             setupCorsHeaders(response, configuration.getCorsHeaders());
         }

         List<RestDefinition> rests = null;
         if (camelContext != null && camelContext.getName().equals(contextId)) {
             rests = getRestDefinitions(camelContext);
         } else {
             rests = getRestDefinitions(contextId);
         }

         if (rests != null) {
             final Map<String, Object> apiProperties = configuration.getApiProperties() != null ? configuration.getApiProperties() : new HashMap<>();
             if (json) {
                 response.setHeader(Exchange.CONTENT_TYPE, (String) apiProperties.getOrDefault("api.specification.contentType.json", "application/json"));

                 // read the rest-dsl into swagger model
                 Swagger swagger = reader.read(rests, route, swaggerConfig, contextId, classResolver);
                 if (configuration.isUseXForwardHeaders()) {
                     setupXForwardedHeaders(swagger, headers);
                 }

                 if (!configuration.isApiVendorExtension()) {
                     clearVendorExtensions(swagger);
                 }

                 byte[] bytes = mapper.writeValueAsBytes(swagger);

                 int len = bytes.length;
                 response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

                 response.writeBytes(bytes);
             } else {
                 response.setHeader(Exchange.CONTENT_TYPE, (String) apiProperties.getOrDefault("api.specification.contentType.yaml", "text/yaml"));

                 // read the rest-dsl into swagger model
                 Swagger swagger = reader.read(rests, route, swaggerConfig, contextId, classResolver);
                 if (configuration.isUseXForwardHeaders()) {
                     setupXForwardedHeaders(swagger, headers);
                 }

                 if (!configuration.isApiVendorExtension()) {
                     clearVendorExtensions(swagger);
                 }

                 byte[] jsonData = mapper.writeValueAsBytes(swagger);

                 // json to yaml
                 JsonNode node = mapper.readTree(jsonData);
                 byte[] bytes = Yaml.mapper().writerWithDefaultPrettyPrinter().writeValueAsBytes(node);

                 int len = bytes.length;
                 response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

                 response.writeBytes(bytes);
             }
         } else {
             response.noContent();
         }
     }

     /**
      * Renders a list of available CamelContexts in the JVM
      */
     public void renderCamelContexts(RestApiResponseAdapter response, String contextId, String contextIdPattern, boolean json, boolean yaml,
                                     RestConfiguration configuration) throws Exception {
         LOG.trace("renderCamelContexts");

         if (cors) {
             setupCorsHeaders(response, configuration.getCorsHeaders());
         }

         List<String> contexts = findCamelContexts();

         // filter non matched CamelContext's
         if (contextIdPattern != null) {
             Iterator<String> it = contexts.iterator();
             while (it.hasNext()) {
                 String name = it.next();

                 boolean match;
                 if ("#name#".equals(contextIdPattern)) {
                     match = name.equals(contextId);
                 } else {
                     match = PatternHelper.matchPattern(name, contextIdPattern);
                 }
                 if (!match) {
                     it.remove();
                 }
             }
         }

         StringBuffer sb = new StringBuffer();

         if (json) {
             response.setHeader(Exchange.CONTENT_TYPE, "application/json");

             sb.append("[\n");
             for (int i = 0; i < contexts.size(); i++) {
                 String name = contexts.get(i);
                 sb.append("{\"name\": \"").append(name).append("\"}");
                 if (i < contexts.size() - 1) {
                     sb.append(",\n");
                 }
             }
             sb.append("\n]");
         } else {
             response.setHeader(Exchange.CONTENT_TYPE, "text/yaml");

             for (int i = 0; i < contexts.size(); i++) {
                 String name = contexts.get(i);
                 sb.append("- \"").append(name).append("\"\n");
             }
         }

         int len = sb.length();
         response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

         response.writeBytes(sb.toString().getBytes());
     }

     private static void setupCorsHeaders(RestApiResponseAdapter response, Map<String, String> corsHeaders) {
         // use default value if none has been configured
         String allowOrigin = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Origin") : null;
         if (allowOrigin == null) {
             allowOrigin = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_ORIGIN;
         }
         String allowMethods = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Methods") : null;
         if (allowMethods == null) {
             allowMethods = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_METHODS;
         }
         String allowHeaders = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Headers") : null;
         if (allowHeaders == null) {
             allowHeaders = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_HEADERS;
         }
         String maxAge = corsHeaders != null ? corsHeaders.get("Access-Control-Max-Age") : null;
         if (maxAge == null) {
             maxAge = RestConfiguration.CORS_ACCESS_CONTROL_MAX_AGE;
         }

         if (LOG.isTraceEnabled()) {
             LOG.trace("Using CORS headers[");
             LOG.trace("  Access-Control-Allow-Origin={}", allowOrigin);
             LOG.trace("  Access-Control-Allow-Methods={}", allowMethods);
             LOG.trace("  Access-Control-Allow-Headers={}", allowHeaders);
             LOG.trace("  Access-Control-Max-Age={}", maxAge);
             LOG.trace("]");
         }
         response.setHeader("Access-Control-Allow-Origin", allowOrigin);
         response.setHeader("Access-Control-Allow-Methods", allowMethods);
         response.setHeader("Access-Control-Allow-Headers", allowHeaders);
         response.setHeader("Access-Control-Max-Age", maxAge);
     }

     static void setupXForwardedHeaders(Swagger swagger, Map<String, Object> headers) {

         String host = (String) headers.get(HEADER_HOST);
         if (ObjectHelper.isNotEmpty(host)) {
             swagger.setHost(host);
         }

         String forwardedPrefix = (String) headers.get(HEADER_X_FORWARDED_PREFIX);
         if (ObjectHelper.isNotEmpty(forwardedPrefix)) {
             swagger.setBasePath(URISupport.joinPaths(forwardedPrefix, swagger.getBasePath()));
         }

         String forwardedHost = (String) headers.get(HEADER_X_FORWARDED_HOST);
         if (ObjectHelper.isNotEmpty(forwardedHost)) {
             swagger.setHost(forwardedHost);
         }

         String proto = (String) headers.get(HEADER_X_FORWARDED_PROTO);
         if (ObjectHelper.isNotEmpty(proto)) {
             String[] schemes = proto.split(",");
             for (String scheme : schemes) {
                 String trimmedScheme = scheme.trim();
                 if (ObjectHelper.isNotEmpty(trimmedScheme)) {
                     swagger.addScheme(Scheme.forValue(trimmedScheme));
                 }
             }
         }
     }

 }
	/*
	* 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.camel.swagger;

	import java.io.ByteArrayInputStream;
	import java.io.InputStream;
	import java.lang.management.ManagementFactory;
	import java.nio.charset.StandardCharsets;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.concurrent.atomic.AtomicBoolean;

	import javax.management.AttributeNotFoundException;
	import javax.management.MBeanServer;
	import javax.management.ObjectName;

	import org.w3c.dom.Document;

	import com.fasterxml.jackson.annotation.JsonInclude;
	import com.fasterxml.jackson.databind.JsonNode;
	import com.fasterxml.jackson.databind.ObjectMapper;
	import com.fasterxml.jackson.databind.SerializationFeature;
	import io.swagger.jaxrs.config.BeanConfig;
	import io.swagger.models.Contact;
	import io.swagger.models.Info;
	import io.swagger.models.License;
	import io.swagger.models.Scheme;
	import io.swagger.models.Swagger;
	import io.swagger.util.Json;
	import io.swagger.util.Yaml;
	import org.apache.camel.CamelContext;
	import org.apache.camel.Exchange;
	import org.apache.camel.model.Model;
	import org.apache.camel.model.ModelHelper;
	import org.apache.camel.model.rest.RestDefinition;
	import org.apache.camel.model.rest.RestsDefinition;
	import org.apache.camel.spi.ClassResolver;
	import org.apache.camel.spi.RestConfiguration;
	import org.apache.camel.support.PatternHelper;
	import org.apache.camel.util.CamelVersionHelper;
	import org.apache.camel.util.ObjectHelper;
	import org.apache.camel.util.URISupport;
	import org.apache.camel.util.xml.XmlLineNumberParser;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import static org.apache.camel.swagger.SwaggerHelper.clearVendorExtensions;

	/**
	* A support class for that allows SPI to plugin
	* and offer Swagger API service listings as part of the Camel component. This allows rest-dsl components
	* such as servlet/jetty/netty-http to offer Swagger API listings with minimal effort.
	*/
	public class RestSwaggerSupport {

	static final String HEADER_X_FORWARDED_PREFIX = "X-Forwarded-Prefix";
	static final String HEADER_X_FORWARDED_HOST = "X-Forwarded-Host";
	static final String HEADER_X_FORWARDED_PROTO = "X-Forwarded-Proto";
	static final String HEADER_HOST = "Host";

	private static final Logger LOG = LoggerFactory.getLogger(RestSwaggerSupport.class);
	private RestSwaggerReader reader = new RestSwaggerReader();
	private boolean cors;

	public void initSwagger(BeanConfig swaggerConfig, Map<String, Object> config) {
	// configure swagger options
	String s = (String) config.get("swagger.version");
	if (s != null) {
	swaggerConfig.setVersion(s);
	}
	s = (String) config.get("base.path");
	if (s != null) {
	swaggerConfig.setBasePath(s);
	}
	s = (String) config.get("host");
	if (s != null) {
	swaggerConfig.setHost(s);
	}
	s = (String) config.get("cors");
	if (s != null) {
	cors = "true".equalsIgnoreCase(s);
	}
	s = (String) config.get("schemes");
	if (s == null) {
	// deprecated due typo
	s = (String) config.get("schemas");
	}
	if (s != null) {
	String[] schemes = s.split(",");
	swaggerConfig.setSchemes(schemes);
	} else {
	// assume http by default
	swaggerConfig.setSchemes(new String[]{"http"});
	}

	String version = (String) config.get("api.version");
	String title = (String) config.get("api.title");
	String description = (String) config.get("api.description");
	String termsOfService = (String) config.get("api.termsOfService");
	String licenseName = (String) config.get("api.license.name");
	String licenseUrl = (String) config.get("api.license.url");
	String contactName = (String) config.get("api.contact.name");
	String contactUrl = (String) config.get("api.contact.url");
	String contactEmail = (String) config.get("api.contact.email");

	Info info = new Info();
	info.setVersion(version);
	info.setTitle(title);
	info.setDescription(description);
	info.setTermsOfService(termsOfService);

	if (licenseName != null \|\| licenseUrl != null) {
	License license = new License();
	license.setName(licenseName);
	license.setUrl(licenseUrl);
	info.setLicense(license);
	}

	if (contactName != null \|\| contactUrl != null \|\| contactEmail != null) {
	Contact contact = new Contact();
	contact.setName(contactName);
	contact.setUrl(contactUrl);
	contact.setEmail(contactEmail);
	info.setContact(contact);
	}

	swaggerConfig.setInfo(info);
	}

	public List<RestDefinition> getRestDefinitions(CamelContext camelContext) throws Exception {
	Model model = camelContext.getExtension(Model.class);
	List<RestDefinition> rests = model.getRestDefinitions();
	if (rests.isEmpty()) {
	return null;
	}

	// use a routes definition to dump the rests
	RestsDefinition def = new RestsDefinition();
	def.setRests(rests);
	String xml = ModelHelper.dumpModelAsXml(camelContext, def);

	// if resolving placeholders we parse the xml, and resolve the property placeholders during parsing
	final AtomicBoolean changed = new AtomicBoolean();
	InputStream is = new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8));
	Document dom = XmlLineNumberParser.parseXml(is, new XmlLineNumberParser.XmlTextTransformer() {
	@Override
	public String transform(String text) {
	try {
	String after = camelContext.resolvePropertyPlaceholders(text);
	if (!changed.get()) {
	changed.set(!text.equals(after));
	}
	return after;
	} catch (Exception e) {
	// ignore
	return text;
	}
	}
	});
	// okay there were some property placeholder replaced so re-create the model
	if (changed.get()) {
	xml = camelContext.getTypeConverter().mandatoryConvertTo(String.class, dom);
	def = ModelHelper.createModelFromXml(camelContext, xml, RestsDefinition.class);
	if (def != null) {
	return def.getRests();
	}
	}

	return rests;
	}

	public List<RestDefinition> getRestDefinitions(String camelId) throws Exception {
	ObjectName found = null;
	boolean supportResolvePlaceholder = false;

	MBeanServer server = ManagementFactory.getPlatformMBeanServer();
	Set<ObjectName> names = server.queryNames(new ObjectName("org.apache.camel:type=context,*"), null);
	for (ObjectName on : names) {
	String id = on.getKeyProperty("name");
	if (id.startsWith("\"") && id.endsWith("\"")) {
	id = id.substring(1, id.length() - 1);
	}
	if (camelId == null \|\| camelId.equals(id)) {
	// filter out older Camel versions as this requires Camel 2.15 or better (rest-dsl)
	String version = (String) server.getAttribute(on, "CamelVersion");
	if (CamelVersionHelper.isGE("2.15.0", version)) {
	found = on;
	}
	if (CamelVersionHelper.isGE("2.15.3", version)) {
	supportResolvePlaceholder = true;
	}
	}
	}

	if (found != null) {
	String xml;
	if (supportResolvePlaceholder) {
	xml = (String) server.invoke(found, "dumpRestsAsXml", new Object[]{true}, new String[]{"boolean"});
	} else {
	xml = (String) server.invoke(found, "dumpRestsAsXml", null, null);
	}
	if (xml != null) {
	LOG.debug("DumpRestAsXml:\n{}", xml);
	RestsDefinition rests = ModelHelper.createModelFromXml(null, xml, RestsDefinition.class);
	if (rests != null) {
	return rests.getRests();
	}
	}
	}

	return null;
	}

	public List<String> findCamelContexts() throws Exception {
	List<String> answer = new ArrayList<>();

	MBeanServer server = ManagementFactory.getPlatformMBeanServer();
	Set<ObjectName> names = server.queryNames(new ObjectName(":type=context,"), null);
	for (ObjectName on : names) {

	String id = on.getKeyProperty("name");
	if (id.startsWith("\"") && id.endsWith("\"")) {
	id = id.substring(1, id.length() - 1);
	}

	// filter out older Camel versions as this requires Camel 2.15 or better (rest-dsl)
	try {
	String version = (String) server.getAttribute(on, "CamelVersion");
	if (CamelVersionHelper.isGE("2.15.0", version)) {
	answer.add(id);
	}
	} catch (AttributeNotFoundException ex) {
	// ignore
	}
	}
	return answer;
	}

	public void renderResourceListing(CamelContext camelContext, RestApiResponseAdapter response, BeanConfig swaggerConfig, String contextId, String route, boolean json, boolean yaml,
	Map<String, Object> headers, ClassResolver classResolver, RestConfiguration configuration) throws Exception {
	LOG.trace("renderResourceListing");

	ObjectMapper mapper = Json.mapper();
	mapper.enable(SerializationFeature.INDENT_OUTPUT);
	mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

	if (cors) {
	setupCorsHeaders(response, configuration.getCorsHeaders());
	}

	List<RestDefinition> rests = null;
	if (camelContext != null && camelContext.getName().equals(contextId)) {
	rests = getRestDefinitions(camelContext);
	} else {
	rests = getRestDefinitions(contextId);
	}

	if (rests != null) {
	final Map<String, Object> apiProperties = configuration.getApiProperties() != null ? configuration.getApiProperties() : new HashMap<>();
	if (json) {
	response.setHeader(Exchange.CONTENT_TYPE, (String) apiProperties.getOrDefault("api.specification.contentType.json", "application/json"));

	// read the rest-dsl into swagger model
	Swagger swagger = reader.read(rests, route, swaggerConfig, contextId, classResolver);
	if (configuration.isUseXForwardHeaders()) {
	setupXForwardedHeaders(swagger, headers);
	}

	if (!configuration.isApiVendorExtension()) {
	clearVendorExtensions(swagger);
	}

	byte[] bytes = mapper.writeValueAsBytes(swagger);

	int len = bytes.length;
	response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

	response.writeBytes(bytes);
	} else {
	response.setHeader(Exchange.CONTENT_TYPE, (String) apiProperties.getOrDefault("api.specification.contentType.yaml", "text/yaml"));

	// read the rest-dsl into swagger model
	Swagger swagger = reader.read(rests, route, swaggerConfig, contextId, classResolver);
	if (configuration.isUseXForwardHeaders()) {
	setupXForwardedHeaders(swagger, headers);
	}

	if (!configuration.isApiVendorExtension()) {
	clearVendorExtensions(swagger);
	}

	byte[] jsonData = mapper.writeValueAsBytes(swagger);

	// json to yaml
	JsonNode node = mapper.readTree(jsonData);
	byte[] bytes = Yaml.mapper().writerWithDefaultPrettyPrinter().writeValueAsBytes(node);

	int len = bytes.length;
	response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

	response.writeBytes(bytes);
	}
	} else {
	response.noContent();
	}
	}

	/**
	* Renders a list of available CamelContexts in the JVM
	*/
	public void renderCamelContexts(RestApiResponseAdapter response, String contextId, String contextIdPattern, boolean json, boolean yaml,
	RestConfiguration configuration) throws Exception {
	LOG.trace("renderCamelContexts");

	if (cors) {
	setupCorsHeaders(response, configuration.getCorsHeaders());
	}

	List<String> contexts = findCamelContexts();

	// filter non matched CamelContext's
	if (contextIdPattern != null) {
	Iterator<String> it = contexts.iterator();
	while (it.hasNext()) {
	String name = it.next();

	boolean match;
	if ("#name#".equals(contextIdPattern)) {
	match = name.equals(contextId);
	} else {
	match = PatternHelper.matchPattern(name, contextIdPattern);
	}
	if (!match) {
	it.remove();
	}
	}
	}

	StringBuffer sb = new StringBuffer();

	if (json) {
	response.setHeader(Exchange.CONTENT_TYPE, "application/json");

	sb.append("[\n");
	for (int i = 0; i < contexts.size(); i++) {
	String name = contexts.get(i);
	sb.append("{\"name\": \"").append(name).append("\"}");
	if (i < contexts.size() - 1) {
	sb.append(",\n");
	}
	}
	sb.append("\n]");
	} else {
	response.setHeader(Exchange.CONTENT_TYPE, "text/yaml");

	for (int i = 0; i < contexts.size(); i++) {
	String name = contexts.get(i);
	sb.append("- \"").append(name).append("\"\n");
	}
	}

	int len = sb.length();
	response.setHeader(Exchange.CONTENT_LENGTH, "" + len);

	response.writeBytes(sb.toString().getBytes());
	}

	private static void setupCorsHeaders(RestApiResponseAdapter response, Map<String, String> corsHeaders) {
	// use default value if none has been configured
	String allowOrigin = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Origin") : null;
	if (allowOrigin == null) {
	allowOrigin = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_ORIGIN;
	}
	String allowMethods = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Methods") : null;
	if (allowMethods == null) {
	allowMethods = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_METHODS;
	}
	String allowHeaders = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Headers") : null;
	if (allowHeaders == null) {
	allowHeaders = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_HEADERS;
	}
	String maxAge = corsHeaders != null ? corsHeaders.get("Access-Control-Max-Age") : null;
	if (maxAge == null) {
	maxAge = RestConfiguration.CORS_ACCESS_CONTROL_MAX_AGE;
	}

	if (LOG.isTraceEnabled()) {
	LOG.trace("Using CORS headers[");
	LOG.trace(" Access-Control-Allow-Origin={}", allowOrigin);
	LOG.trace(" Access-Control-Allow-Methods={}", allowMethods);
	LOG.trace(" Access-Control-Allow-Headers={}", allowHeaders);
	LOG.trace(" Access-Control-Max-Age={}", maxAge);
	LOG.trace("]");
	}
	response.setHeader("Access-Control-Allow-Origin", allowOrigin);
	response.setHeader("Access-Control-Allow-Methods", allowMethods);
	response.setHeader("Access-Control-Allow-Headers", allowHeaders);
	response.setHeader("Access-Control-Max-Age", maxAge);
	}

	static void setupXForwardedHeaders(Swagger swagger, Map<String, Object> headers) {

	String host = (String) headers.get(HEADER_HOST);
	if (ObjectHelper.isNotEmpty(host)) {
	swagger.setHost(host);
	}

	String forwardedPrefix = (String) headers.get(HEADER_X_FORWARDED_PREFIX);
	if (ObjectHelper.isNotEmpty(forwardedPrefix)) {
	swagger.setBasePath(URISupport.joinPaths(forwardedPrefix, swagger.getBasePath()));
	}

	String forwardedHost = (String) headers.get(HEADER_X_FORWARDED_HOST);
	if (ObjectHelper.isNotEmpty(forwardedHost)) {
	swagger.setHost(forwardedHost);
	}

	String proto = (String) headers.get(HEADER_X_FORWARDED_PROTO);
	if (ObjectHelper.isNotEmpty(proto)) {
	String[] schemes = proto.split(",");
	for (String scheme : schemes) {
	String trimmedScheme = scheme.trim();
	if (ObjectHelper.isNotEmpty(trimmedScheme)) {
	swagger.addScheme(Scheme.forValue(trimmedScheme));
	}
	}
	}
	}

	}