HTTP4 — provides endpoints for consuming external HTTP resources using Apache HttpClient 4.x
Available as of Camel 2.3
The HTTP4 component provides HTTP based endpoints for consuming external HTTP resources (as a client to call external servers using HTTP).
![]() | Important |
---|---|
camel-http4 vs camel-jetty: You can only produce to endpoints generated by the HTTP4 component. Therefore it should never be used as input into your Camel Routes. To bind/expose an HTTP endpoint via a HTTP server as input to a Camel route, use the Jetty component instead. |
![]() | Note |
---|---|
camel-http4 vs camel-http: Camel-http4 uses HttpClient 4.x while camel-http uses HttpClient 3.x. |
The URI format for an HTTP4 endpoint is:
http(s)4:hostname
[:port
][/resourceUri
][?options
]
By default the port is set to 80
for HTTP and to
443
for HTTPS.
You can append query options to the URI in the following format,
?option=value&option=value&...
Maven users will need to add a dependency on
camel-http4
to their pom.xml
for this component:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-http4</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
Name | Default Value | Description |
---|---|---|
maxTotalConnections
|
200
|
The maximum number of connections. |
connectionsPerRoute
|
20
|
The maximum number of connections per route. |
cookieStore
|
null
|
Camel 2.11.2/2.12.0: To use
a custom
org.apache.http.client.CookieStore .
By default the
org.apache.http.impl.client.BasicCookieStore
is used which is an in-memory only cookie store. Notice if
bridgeEndpoint=true then the cookie
store is forced to be a noop cookie store as cookies
shouldn't be stored as we are just bridging (eg acting as a
proxy). |
httpClientConfigurer
|
null
|
Reference to a
org.apache.camel.component.http.HttpClientConfigurer
in the Registry. |
clientConnectionManager
|
null
|
To use a custom
org.apache.http.conn.ClientConnectionManager .
|
httpBinding
|
null
|
To use a custom
org.apache.camel.component.http.HttpBinding .
|
httpContext
|
null
|
Camel 2.9.2: To use a
custom
org.apache.http.protocol.HttpContext
when executing requests. |
sslContextParameters
|
null
|
Camel 2.8: To use a custom
org.apache.camel.util.jsse.SSLContextParameters .
See Using the JSSE Configuration Utility. |
x509HostnameVerifier
|
BrowserCompat Hostname Verifier
|
Camel 2.7: You can refer to
a different
org.apache.http.conn.ssl.X509HostnameVerifier
instance in the Registry
such as
org.apache.http.conn.ssl.StrictHostnameVerifier
or
org.apache.http.conn.ssl.AllowAllHostnameVerifier .
|
connectionTimeToLive
|
-1
|
Camel 2.11.0: The time for connection to live, the time unit is millisecond, the default value is always keep alive. |
Table 27, “HTTP4 endpoint options” lists the options for an HTTP4 endpoint.
Table 27. HTTP4 endpoint options
Name | Default | Description |
---|---|---|
throwExceptionOn Failure
|
true
| Option to disable throwing the
HttpOperationFailedException
in case of failed responses from the remote server.
This allows you to get all responses regardless of
the HTTP status code. |
bridgeEndpoint
|
false
| If true, HttpProducer will ignore the Exchange.HTTP_URI header, and use the endpoint's URI for request. You may also set the throwExcpetionOnFailure to be false to let the HttpProducer send all fault responses back. Also if set to true HttpProducer and CamelServlet will skip the gzip processing if the content-encoding is "gzip". |
clearExpired Cookies
|
true
| Camel 2.11.2/2.12.0: Whether to clear expired cookies before sending the HTTP request. This ensures the cookies store does not keep growing by adding new cookies which is newer removed when they are expired. |
cookieStore
|
null
| Camel
2.11.2/2.12.0: To use a custom
org.apache.http.client.CookieStore .
By default the
org.apache.http.impl.client.BasicCookieStore
is used which is an in-memory only cookie store.
Notice if bridgeEndpoint=true
then the cookie store is forced to be a noop cookie
store as cookies shouldn't be stored as we are just
bridging (eg acting as a proxy). |
disableStreamCache
|
false
| DefaultHttpBinding will copy the request input stream into a stream cache and put it into the message body if this option is false to support multiple reads, otherwise DefaultHttpBinding will set the request input stream directly in the message body. |
headerFilter Strategy
|
null
| Camel 2.10.4:
Reference to a instance of
org.apache.camel.spi.HeaderFilterStrategy
in the Registry.t will be used to apply the
custom headerFilterStrategy on the new create
HttpEndpoint. |
httpBindingRef
|
null
| Deprecated and will be
removed in Camel 3.0: Reference to a
org.apache.camel.component.http.HttpBinding
in the Registry. Use
the httpBinding option instead. |
httpBinding
|
null
| To use a custom
org.apache.camel.component.http.HttpBinding . |
httpClient ConfigurerRef
|
null
| Deprecated and will be
removed in Camel 3.0: Reference to a
org.apache.camel.component.http.HttpClientConfigurer
in the Registry. Use
the httpClientConfigurer option
instead. |
httpClient Configurer
|
null
| Reference to a
org.apache.camel.component.http.HttpClientConfigurer
in the Registry.
|
httpContextRef
|
null
| Deprecated and will be
removed in Camel 3.0:Camel 2.9.2: Reference to
a custom
org.apache.http.protocol.HttpContext
in the Registry. Use
the httpContext option instead.
|
httpContext
|
null
| Camel 2.9.2: To
use a custom
org.apache.http.protocol.HttpContext
when executing requests. |
httpClient.XXX
|
null
| Setting options on the BasicHttpParams. For instance
httpClient.soTimeout=5000
will set the SO_TIMEOUT to 5
seconds. Look on the setter methods of the following
parameter beans for a complete reference: AuthParamBean, ClientParamBean, ConnConnectionParamBean, ConnRouteParamBean, CookieSpecParamBean, HttpConnectionParamBean and HttpProtocolParamBean
|
clientConnection Manager
|
null
| To use a custom
org.apache.http.conn.ClientConnectionManager . |
transferException
|
false
| 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
HttpOperationFailedException .
The caused exception is required to be serialized. |
sslContext ParametersRef
|
null
| Deprecated to be removed in
Camel 3.0:Camel
2.8: Reference to a
org.apache.camel.util.jsse.SSLContextParameters
in the Registry.
Important: Only
one instance of
org.apache.camel.util.jsse.SSLContextParameters
is supported per HttpComponent. If you need to use
two or more different instances, you must define a
new HttpComponent per instance. See further below
for more details. See Using the JSSE Configuration Utility.
Use the sslContextParameters
option instead. |
sslContext Parameters
|
null
| Camel 2.11.1:
Reference to a
org.apache.camel.util.jsse.SSLContextParameters
in the Registry.
Important: Only
one instance of
org.apache.camel.util.jsse.SSLContextParameters
is supported per HttpComponent. If you need to use 2
or more different instances, you need to define a
new HttpComponent per instance you need. See further
below for more details. See Using the JSSE Configuration Utility.
|
x509Hostname Verifier
|
BrowserCompat Hostname Verifier
| Camel 2.7: You
can refer to a different
org.apache.http.conn.ssl.X509HostnameVerifier
instance in the Registry such as
org.apache.http.conn.ssl.StrictHostnameVerifier
or
org.apache.http.conn.ssl.AllowAllHostnameVerifier .
|
urlRewrite
|
null
| Camel
2.11:Producer
only Refers to a custom
org.apache.camel.component.http4.UrlRewrite
which allows you to rewrite urls when you
bridge/proxy endpoints. See more details at http://camel.apache.org/urlrewrite.html and
How to use Camel as a HTTP proxy between a
client and server. |
The following authentication options can also be set on the HTTP4 endpoint:
Name | Default | Description |
---|---|---|
username
|
null
| Username for authentication. |
password
|
null
| Password for authentication. |
domain
|
null
| The domain name for authentication. |
host
|
null
| The host name authentication. |
proxyHost
|
null
| The proxy host name |
proxyPort
|
null
| The proxy port number |
proxyUsername
|
null
| Username for proxy authentication |
proxyPassword
|
null
| Password for proxy authentication |
proxyDomain
|
null
| The proxy domain name |
proxyNtHost
|
null
| The proxy Nt host name |
authUsername
|
null
| Username for authentication |
authPassword
|
null
| Password for authentication |
authDomain
|
null
| The domain name for authentication |
authHost
|
null
| The host name authentication |
proxyAuthHost
|
null
| The proxy host name |
proxyAuthPort
|
null
| The proxy port number |
proxyAuthScheme
|
null
| The proxy scheme, will fallback and use the scheme from the endpoint if not configured. |
proxyAuthUsername
|
null
| Username for proxy authentication |
proxyAuthPassword
|
null
| Password for proxy authentication |
proxyAuthDomain
|
null
| The proxy domain name |
proxyAuthNtHost
|
null
| The proxy Nt host name |
The following Exchange
properties are recognized by
HTTP4 endpoints:
Table 28. HTTP Exchange properties
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. |
Exchange.HTTP_QUERY
| String
| 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 . |
Apache 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, Apache Camel will add the HTTP response headers as well to the OUT message headers.
Apache Camel will handle according to the HTTP response code:
Response code is in the range 100..299, Apache Camel regards it as a success response.
Response code is in the range 300..399, Apache Camel
regards it as a redirection response and will throw a
HttpOperationFailedException
with the information.
Response code is 400+, Apache Camel regards it as an
external server failure and will throw a
HttpOperationFailedException
with the information.
![]() | Note |
---|---|
The option, |
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
The following algorithm is used to determine whether the
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.
You can get access to these two using the Camel type converter system using NOTE You can get the request and response not just from the processor after the camel-jetty or camel-cxf endpoint.
HttpServletRequest request = exchange.getIn().getBody(HttpServletRequest.class); HttpServletRequest response = exchange.getIn().getBody(HttpServletResponse.class);
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("http4://oldhost");
And the equivalent Spring sample:
<camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <to uri="http4://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("http4://oldhost");
In the sample above Camel will call the http://newhost despite the
endpoint is configured with http4://oldhost. Where Constants is the class,
org.apache.camel.component.http4.Constants
.
If the http4 endpoint is working in bridge mode, it will ignore the
message header of Exchange.HTTP_URI
.
The http 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("http4://oldhost?order=123&detail=short");
Or options provided in a header:
from("direct:start") .setHeader(Exchange.HTTP_QUERY, constant("order=123&detail=short")) .to("http4://oldhost");
The HTTP4 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(org.apache.camel.component.http4.HttpMethods.POST)) .to("http4://www.google.com") .to("mock:results");
The method can be written a bit shorter using the string constants:
.setHeader("CamelHttpMethod", constant("POST"))
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="http4://www.google.com"/> <to uri="mock:results"/> </route> </camelContext>
The HTTP4 component provides a way to configure a proxy.
from("direct:start") .to("http4://oldhost?proxyAuthHost=www.myproxy.com&proxyAuthPort=80");
There is also support for proxy authentication via the
proxyAuthUsername
and
proxyAuthPassword
options.
To avoid System properties conflicts, you can set proxy configuration only from the CamelContext or URI. Java DSL :
context.getProperties().put("http.proxyHost", "172.168.18.9"); context.getProperties().put("http.proxyPort" "8080");
Spring XML
<camelContext> <properties> <property key="http.proxyHost" value="172.168.18.9"/> <property key="http.proxyPort" value="8080"/> </properties> </camelContext>
Camel will first set the settings from Java System or CamelContext Properties and then the endpoint proxy options if provided. So you can override the system properties with the endpoint options.
Notice in Camel 2.8 there is also
a http.proxyScheme
property you can set to
explicit configure the scheme to use.
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");
This sample polls the Google homepage every 10 seconds and write
the page to the file message.html
:
from("timer://foo?fixedRate=true&delay=0&period=10000") .to("http4://www.google.com") .setHeader(FileComponent.HEADER_FILE_NAME, "message.html") .to("file:target/google");
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("http4://www.google.com/search?q=Camel", null);
Map headers = new HashMap(); headers.put(HttpProducer.QUERY, "q=Camel&lr=lang_en"); // we query for Camel and English language at Google template.sendBody("http4://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.
You can get the HTTP response code from the HTTP4 component by
getting the value from the Out message header with
HttpProducer.HTTP_RESPONSE_CODE
.
Exchange exchange = template.send("http4://www.google.com/search", new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().setHeader(HttpProducer.QUERY, constant("hl=en&q=activemq")); } }); Message out = exchange.getOut(); int responseCode = out.getHeader(HttpProducer.HTTP_RESPONSE_CODE, Integer.class);
To disable cookies you can set the HTTP Client to ignore cookies
by adding this URI option:
httpClient.cookiePolicy=ignoreCookies
If you need more control over the HTTP producer you should use the
HttpComponent
where you can set various
classes to give you custom behavior.
As of Camel 2.8, the HTTP4 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 HTTP4 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); HttpComponent httpComponent = getContext().getComponent("http4", HttpComponent.class); httpComponent.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="https4://127.0.0.1/mail/?sslContextParametersRef=sslContextParameters"/>...
Basically camel-http4 component is built on the top of Apache HTTP client.
Please see SSL/TLS customization for details or have a look into
the
org.apache.camel.component.http4.HttpsServerTestSupport
unit test base class. You can also implement a custom
org.apache.camel.component.http4.HttpClientConfigurer
to do some configuration on the http client if you need full control
of it.
However if you just want to specify the
keystore and truststore you can do this with Apache HTTP
HttpClientConfigurer
, for example:
KeyStore keystore = ...; KeyStore truststore = ...; SchemeRegistry registry = new SchemeRegistry(); registry.register(new Scheme("https", 443, new SSLSocketFactory(keystore, "mypassword", truststore)));
And then you need to create a class that implements
HttpClientConfigurer
, and registers https
protocol providing a keystore or truststore per example above. Then,
from your camel route builder class you can hook it up like
so:
HttpComponent httpComponent = getContext().getComponent("http4", HttpComponent.class); httpComponent.setHttpClientConfigurer(new MyHttpClientConfigurer());
If you are doing this using the Spring DSL, you can specify your
HttpClientConfigurer
using the URI. For
example:
<bean id="myHttpClientConfigurer" class="my.https.HttpClientConfigurer"> </bean> <to uri="https4://myhostname.com:443/myURL?httpClientConfigurer=myHttpClientConfigurer"/>
As long as you implement the HttpClientConfigurer and configure your keystore and truststore as described above, it will work fine.
An end user reported that he had problem with authenticating with
HTTPS. The problem was eventually resolved by providing a custom
configured
org.apache.http.protocol.HttpContext
:
1. Create a (Spring) factory for HttpContexts:
public class HttpContextFactory { private String httpHost = "localhost"; private String httpPort = 9001; private BasicHttpContext httpContext = new BasicHttpContext(); private BasicAuthCache authCache = new BasicAuthCache(); private BasicScheme basicAuth = new BasicScheme(); public HttpContext getObject() { authCache.put(new HttpHost(httpHost, httpPort), basicAuth); httpContext.setAttribute(ClientContext.AUTH_CACHE, authCache); return httpContext; } // getter and setter }
2. Declare an HttpContext in the Spring application context file:
<bean id="myHttpContext" factory-bean="httpContextFactory" factory-method="getObject"/>
3. Reference the context in the http4 URL:
<to uri="https4://myhostname.com:443/myURL?httpContext=myHttpContext"/>
The HTTP4 component supports only one instance of
org.apache.camel.util.jsse.SSLContextParameters
per component. If you need to use two or more different instances,
you need to setup multiple components as shown below. Here we have two
components, each using their own instance of
sslContextParameters
property.
<bean id="http4-foo" class="org.apache.camel.component.http4.HttpComponent"> <property name="sslContextParameters" ref="sslContextParams1"/> <property name="x509HostnameVerifier" ref="hostnameVerifier"/> </bean> <bean id="http4-bar" class="org.apache.camel.component.http4.HttpComponent"> <property name="sslContextParameters" ref="sslContextParams2"/> <property name="x509HostnameVerifier" ref="hostnameVerifier"/> </bean>