Chapter 3. AHC Component Available as of Camel version 2.8 The ahc: component provides HTTP based endpoints for consuming external HTTP resources (as a client to call external servers using HTTP). The component uses the Async Http Client library. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ahc</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> 3.1. URI format ahc:http://hostname[:port][/resourceUri][?options] ahc:https://hostname[:port][/resourceUri][?options] Will by default use port 80 for HTTP and 443 for HTTPS. You can append query options to the URI in the following format, ?option=value&option=value&... 3.2. AhcEndpoint Options The AHC endpoint is configured using URI syntax: with the following path and query parameters: 3.2.1. Path Parameters (1 parameters): Name Description Default Type httpUri Required The URI to use such as http://hostname:port/path URI 3.2.2. Query Parameters (13 parameters): Name Description Default Type bridgeEndpoint (producer) If the option is true, then the Exchange.HTTP_URI header is ignored, and use the endpoint's URI for request. You may also set the throwExceptionOnFailure to be false to let the AhcProducer send all the fault response back. false boolean bufferSize (producer) The initial in-memory buffer size used when transferring data between Camel and AHC Client. 4096 int connectionClose (producer) Define if the Connection Close header has to be added to HTTP Request. This parameter is false by default false boolean cookieHandler (producer) Configure a cookie handler to maintain a HTTP session CookieHandler headerFilterStrategy (producer) To use a custom HeaderFilterStrategy to filter header to and from Camel message. HeaderFilterStrategy throwExceptionOnFailure (producer) Option to disable throwing the AhcOperationFailedException in case of failed responses from the remote server. This allows you to get all responses regardless of the HTTP status code. true boolean transferException (producer) If enabled and an Exchange failed processing on the consumer side, and if the caused Exception was send back serialized in the response as a application/x-java-serialized-object content type (for example using Jetty or Servlet Camel components). On the producer side the exception will be deserialized and thrown as is, instead of the AhcOperationFailedException. The caused exception is required to be serialized. This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. false boolean binding (advanced) To use a custom AhcBinding which allows to control how to bind between AHC and Camel. AhcBinding clientConfig (advanced) To configure the AsyncHttpClient to use a custom com.ning.http.client.AsyncHttpClientConfig instance. AsyncHttpClientConfig clientConfigOptions (advanced) To configure the AsyncHttpClientConfig using the key/values from the Map. Map synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean clientConfigRealmOptions (security) To configure the AsyncHttpClientConfig Realm using the key/values from the Map. Map sslContextParameters (security) Reference to a org.apache.camel.util.jsse.SSLContextParameters in the Registry. This reference overrides any configured SSLContextParameters at the component level. See Using the JSSE Configuration Utility. Note that configuring this option will override any SSL/TLS configuration options provided through the clientConfig option at the endpoint or component level. SSLContextParameters 3.3. Spring Boot Auto-Configuration The component supports 9 options, which are listed below. Name Description Default Type camel.component.ahc.allow-java-serialized-object Whether to allow java serialization when a request uses context-type=application/x-java-serialized-object This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. false Boolean camel.component.ahc.binding To use a custom AhcBinding which allows to control how to bind between AHC and Camel. The option is a org.apache.camel.component.ahc.AhcBinding type. String camel.component.ahc.client To use a custom AsyncHttpClient. The option is a org.asynchttpclient.AsyncHttpClient type. String camel.component.ahc.client-config To configure the AsyncHttpClient to use a custom com.ning.http.client.AsyncHttpClientConfig instance. The option is a org.asynchttpclient.AsyncHttpClientConfig type. String camel.component.ahc.enabled Enable ahc component true Boolean camel.component.ahc.header-filter-strategy To use a custom org.apache.camel.spi.HeaderFilterStrategy to filter header to and from Camel message. The option is a org.apache.camel.spi.HeaderFilterStrategy type. String camel.component.ahc.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean camel.component.ahc.ssl-context-parameters Reference to a org.apache.camel.util.jsse.SSLContextParameters in the Registry. Note that configuring this option will override any SSL/TLS configuration options provided through the clientConfig option at the endpoint or component level. The option is a org.apache.camel.util.jsse.SSLContextParameters type. String camel.component.ahc.use-global-ssl-context-parameters Enable usage of global SSL context parameters. false Boolean 3.4. AhcComponent Options The AHC component supports 8 options, which are listed below. Name Description Default Type client (advanced) To use a custom AsyncHttpClient AsyncHttpClient binding (advanced) To use a custom AhcBinding which allows to control how to bind between AHC and Camel. AhcBinding clientConfig (advanced) To configure the AsyncHttpClient to use a custom com.ning.http.client.AsyncHttpClientConfig instance. AsyncHttpClientConfig sslContextParameters (security) Reference to a org.apache.camel.util.jsse.SSLContextParameters in the Registry. Note that configuring this option will override any SSL/TLS configuration options provided through the clientConfig option at the endpoint or component level. SSLContextParameters allowJavaSerialized Object (advanced) Whether to allow java serialization when a request uses context-type=application/x-java-serialized-object This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. false boolean useGlobalSslContext Parameters (security) Enable usage of global SSL context parameters. false boolean headerFilterStrategy (filter) To use a custom org.apache.camel.spi.HeaderFilterStrategy to filter header to and from Camel message. HeaderFilterStrategy resolveProperty Placeholders (advanced) Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true boolean Notice that setting any of the options on the AhcComponent will propagate those options to AhcEndpoints being created. However the AhcEndpoint can also configure/override a custom option. Options set on endpoints will always take precedence over options from the AhcComponent . 3.5. Message Headers Name Type Description Exchange.HTTP_URI String URI to call. Will override existing URI set directly on the endpoint. Exchange.HTTP_PATH String Request URI's path, the header will be used to build the request URI with the HTTP_URI. If the path is start with "/", http producer will try to find the relative path based on the Exchange.HTTP_BASE_URI header or the exchange.getFromEndpoint().getEndpointUri(); Exchange.HTTP_QUERY String Camel 2.11 onwards: URI parameters. Will override existing URI parameters set directly on the endpoint. Exchange.HTTP_RESPONSE_CODE int The HTTP response code from the external server. Is 200 for OK. Exchange.HTTP_CHARACTER_ENCODING String Character encoding. Exchange.CONTENT_TYPE String The HTTP content type. Is set on both the IN and OUT message to provide a content type, such as text/html . Exchange.CONTENT_ENCODING String The HTTP content encoding. Is set on both the IN and OUT message to provide a content encoding, such as gzip . 3.6. Message Body Camel will store the HTTP response from the external server on the OUT body. All headers from the IN message will be copied to the OUT message, so headers are preserved during routing. Additionally Camel will add the HTTP response headers as well to the OUT message headers. 3.7. Response code Camel will handle according to the HTTP response code: Response code is in the range 100..299, Camel regards it as a success response. Response code is in the range 300..399, Camel regards it as a redirection response and will throw a AhcOperationFailedException with the information. Response code is 400+, Camel regards it as an external server failure and will throw a AhcOperationFailedException with the information. throwExceptionOnFailure The option, throwExceptionOnFailure , can be set to false to prevent the AhcOperationFailedException from being thrown for failed response codes. This allows you to get any response from the remote server. 3.8. AhcOperationFailedException This exception contains the following information: The HTTP status code The HTTP status line (text of the status code) Redirect location, if server returned a redirect Response body as a java.lang.String , if server provided a body as response 3.9. Calling using GET or POST The following algorithm is used to determine if either GET or POST HTTP method should be used: 1. Use method provided in header. 2. GET if query string is provided in header. 3. GET if endpoint is configured with a query string. 4. POST if there is data to send (body is not null). 5. GET otherwise. 3.10. Configuring URI to call You can set the HTTP producer's URI directly form the endpoint URI. In the route below, Camel will call out to the external server, oldhost , using HTTP. from("direct:start") .to("ahc:http://oldhost"); And the equivalent Spring sample: <camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <to uri="ahc:http://oldhost"/> </route> </camelContext> You can override the HTTP endpoint URI by adding a header with the key, Exchange.HTTP_URI , on the message. from("direct:start") .setHeader(Exchange.HTTP_URI, constant("http://newhost")) .to("ahc:http://oldhost"); 3.11. Configuring URI Parameters The ahc producer supports URI parameters to be sent to the HTTP server. The URI parameters can either be set directly on the endpoint URI or as a header with the key Exchange.HTTP_QUERY on the message. from("direct:start") .to("ahc:http://oldhost?order=123&detail=short"); Or options provided in a header: from("direct:start") .setHeader(Exchange.HTTP_QUERY, constant("order=123&detail=short")) .to("ahc:http://oldhost"); 3.12. How to set the http method to the HTTP producer The HTTP component provides a way to set the HTTP request method by setting the message header. Here is an example; from("direct:start") .setHeader(Exchange.HTTP_METHOD, constant("POST")) .to("ahc:http://www.google.com") .to("mock:results"); And the equivalent Spring sample: <camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <setHeader headerName="CamelHttpMethod"> <constant>POST</constant> </setHeader> <to uri="ahc:http://www.google.com"/> <to uri="mock:results"/> </route> </camelContext> 3.13. Configuring charset If you are using POST to send data you can configure the charset using the Exchange property: exchange.setProperty(Exchange.CHARSET_NAME, "iso-8859-1"); 3.13.1. URI Parameters from the endpoint URI In this sample we have the complete URI endpoint that is just what you would have typed in a web browser. Multiple URI parameters can of course be set using the & character as separator, just as you would in the web browser. Camel does no tricks here. // we query for Camel at the Google page template.sendBody("ahc:http://www.google.com/search?q=Camel", null); 3.13.2. URI Parameters from the Message Map headers = new HashMap(); headers.put(Exchange.HTTP_QUERY, "q=Camel&lr=lang_en"); // we query for Camel and English language at Google template.sendBody("ahc:http://www.google.com/search", null, headers); In the header value above notice that it should not be prefixed with ? and you can separate parameters as usual with the & char. 3.13.3. Getting the Response Code You can get the HTTP response code from the AHC component by getting the value from the Out message header with Exchange.HTTP_RESPONSE_CODE . Exchange exchange = template.send("ahc:http://www.google.com/search", new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().setHeader(Exchange.HTTP_QUERY, constant("hl=en&q=activemq")); } }); Message out = exchange.getOut(); int responseCode = out.getHeader(Exchange.HTTP_RESPONSE_CODE, Integer.class); 3.14. Configuring AsyncHttpClient The AsyncHttpClient client uses a AsyncHttpClientConfig to configure the client. See the documentation at Async Http Client for more details. In Camel 2.8 , configuration is limited to using the builder pattern provided by AsyncHttpClientConfig.Builder . In Camel 2.8, the AsyncHttpClientConfig doesn't support getters/setters so its not easy to create/configure using a Spring bean style (eg the <bean> tag in the XML file). The example below shows how to use a builder to create the AsyncHttpClientConfig which we configure on the AhcComponent . In Camel 2.9 , the AHC component uses Async HTTP library 1.6.4. This newer version provides added support for plain bean style configuration. The AsyncHttpClientConfigBean class provides getters and setters for the configuration options available in AsyncHttpClientConfig . An instance of AsyncHttpClientConfigBean may be passed directly to the AHC component or referenced in an endpoint URI using the clientConfig URI parameter. Also available in Camel 2.9 is the ability to set configuration options directly in the URI. URI parameters starting with "clientConfig." can be used to set the various configurable properties of AsyncHttpClientConfig . The properties specified in the endpoint URI are merged with those specified in the configuration referenced by the "clientConfig" URI parameter with those being set using the "clientConfig." parameter taking priority. The AsyncHttpClientConfig instance referenced is always copied for each endpoint such that settings on one endpoint will remain independent of settings on any previously created endpoints. The example below shows how to configure the AHC component using the "clientConfig." type URI parameters. from("direct:start") .to("ahc:http://localhost:8080/foo?clientConfig.maxRequestRetry=3&clientConfig.followRedirects=true") 3.15. SSL Support (HTTPS) Using the JSSE Configuration Utility As of Camel 2.9, the AHC component supports SSL/TLS configuration through the Camel JSSE Configuration Utility . This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the AHC component. Programmatic configuration of the component KeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); AhcComponent component = context.getComponent("ahc", AhcComponent.class); component.setSslContextParameters(scp)); Spring DSL based configuration of endpoint ... <camel:sslContextParameters id="sslContextParameters"> <camel:keyManagers keyPassword="keyPassword"> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> </camel:sslContextParameters>... ... <to uri="ahc:https://localhost/foo?sslContextParameters=#sslContextParameters"/> ... 3.16. See Also Configuring Camel Component Endpoint Getting Started Jetty HTTP HTTP4

Commands:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ahc</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
ahc:http://hostname[:port][/resourceUri][?options] ahc:https://hostname[:port][/resourceUri][?options]
ahc:httpUri
from("direct:start") .to("ahc:http://oldhost");
<camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <to uri="ahc:http://oldhost"/> </route> </camelContext>
from("direct:start") .setHeader(Exchange.HTTP_URI, constant("http://newhost")) .to("ahc:http://oldhost");
from("direct:start") .to("ahc:http://oldhost?order=123&detail=short");
from("direct:start") .setHeader(Exchange.HTTP_QUERY, constant("order=123&detail=short")) .to("ahc:http://oldhost");
from("direct:start") .setHeader(Exchange.HTTP_METHOD, constant("POST")) .to("ahc:http://www.google.com") .to("mock:results");
<camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <setHeader headerName="CamelHttpMethod"> <constant>POST</constant> </setHeader> <to uri="ahc:http://www.google.com"/> <to uri="mock:results"/> </route> </camelContext>
exchange.setProperty(Exchange.CHARSET_NAME, "iso-8859-1");
// we query for Camel at the Google page template.sendBody("ahc:http://www.google.com/search?q=Camel", null);
Map headers = new HashMap(); headers.put(Exchange.HTTP_QUERY, "q=Camel&lr=lang_en"); // we query for Camel and English language at Google template.sendBody("ahc:http://www.google.com/search", null, headers);
Exchange exchange = template.send("ahc:http://www.google.com/search", new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().setHeader(Exchange.HTTP_QUERY, constant("hl=en&q=activemq")); } }); Message out = exchange.getOut(); int responseCode = out.getHeader(Exchange.HTTP_RESPONSE_CODE, Integer.class);
from("direct:start") .to("ahc:http://localhost:8080/foo?clientConfig.maxRequestRetry=3&clientConfig.followRedirects=true")
KeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); AhcComponent component = context.getComponent("ahc", AhcComponent.class); component.setSslContextParameters(scp));
<camel:sslContextParameters id="sslContextParameters"> <camel:keyManagers keyPassword="keyPassword"> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> </camel:sslContextParameters> <to uri="ahc:https://localhost/foo?sslContextParameters=#sslContextParameters"/>