THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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h2. HTTP Component
The *http:* component provides HTTP based [endpoints|Endpoint] for consuming external HTTP resources (as a client to call external servers using HTTP).
Maven users will need to add the following dependency to their {{pom.xml}} for this component:
{code:xml}
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-http</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
{code}
h3. URI format
{code}
http:hostname[:port][/resourceUri][?param1=value1][¶m2=value2]
{code}
Will by default use port 80 for HTTP and 443 for HTTPS.
{info:title=camel-http vs camel-jetty}
You can only produce to endpoints generated by the HTTP 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, you can use the [Jetty Component|Jetty] or the [Servlet Component|Servlet]
{info}
h3. Examples
Call the url with the body using POST and return response as out message. If body is null call URL using GET and return response as out message
||Java DSL||Spring DSL||
|{code}from("direct:start")
.to("http://myhost/mypath");{code}|{code:xml}<from uri="direct:start"/>
<to uri="http://oldhost"/>{code}|
You can override the HTTP endpoint URI by adding a header. Camel will call the [http://newhost]. This is very handy for e.g. REST urls.
||Java DSL||
|{code}from("direct:start")
.setHeader(Exchange.HTTP_URI, simple("http://myserver/orders/${header.orderId}"))
.to("http://dummyhost");{code}|
URI parameters can either be set directly on the endpoint URI or as a header
||Java DSL||
|{code}
from("direct:start")
.to("http://oldhost?order=123&detail=short");
from("direct:start")
.setHeader(Exchange.HTTP_QUERY, constant("order=123&detail=short"))
.to("http://oldhost");
{code}|
Set the HTTP request method to POST
||Java DSL||Spring DSL||
|{code}from("direct:start")
.setHeader(Exchange.HTTP_METHOD, constant("POST"))
.to("http://www.google.com");
{code}|{code:xml}
<from uri="direct:start"/>
<setHeader headerName="CamelHttpMethod">
<constant>POST</constant>
</setHeader>
<to uri="http://www.google.com"/>
<to uri="mock:results"/>
{code}|
h3. HttpEndpoint Options
{div:class=confluenceTableSmall}
|| Name || Default Value || Description ||
| {{throwExceptionOnFailure}} | {{true}} | Option to disable throwing the {{HttpOperationFailedException}} in case of failed responses from the remote server. This allows you to get all responses regardles of the HTTP status code. |
| {{bridgeEndpoint}} | {{false}} | If the option is 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 the fault response back. \\
*Camel 2.3:* If the option is true, HttpProducer and CamelServlet will skip the gzip processing if the content-encoding is "gzip". |
| {{disableStreamCache}} | {{false}} | DefaultHttpBinding will copy the request input stream into a stream cache and put it into message body if this option is false to support read it twice, otherwise DefaultHttpBinding will set the request input stream direct into the message body. |
| {{httpBindingRef}} | {{null}} | Reference to a {{org.apache.camel.component.http.HttpBinding}} in the [Registry]. From Camel 2.3 onwards prefer to use the {{httpBinding}} option. |
| {{httpBinding}} | {{null}} | Reference to a {{org.apache.camel.component.http.HttpBinding}} in the [Registry]. |
| {{httpClientConfigurerRef}} | {{null}} | Reference to a {{org.apache.camel.component.http.HttpClientConfigurer}} in the [Registry]. From Camel 2.3 onwards prefer to use the {{httpClientConfigurer}} option. |
| {{httpClientConfigurer}} | {{null}} | Reference to a {{org.apache.camel.component.http.HttpClientConfigurer}} in the [Registry]. |
| {{httpClient.XXX}} | {{null}} | Setting options on the [HttpClientParams|http://hc.apache.org/httpclient-3.x/apidocs/org/apache/commons/httpclient/params/HttpClientParams.html]. For instance {{httpClient.soTimeout=5000}} will set the {{SO_TIMEOUT}} to 5 seconds. |
| {{clientConnectionManager}} | {{null}} | To use a custom {{org.apache.http.conn.ClientConnectionManager}}. |
| {{transferException}} | {{false}} | *Camel 2.6:* 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. |
{div}
h3. Authentication and Proxy
The following authentication options can also be set on the HttpEndpoint:
{div:class=confluenceTableSmall}
|| Name || Default Value || Description ||
| {{authMethod}} | {{null}} | Authentication method, either as {{Basic}}, {{Digest}} or {{NTLM}}. |
| {{authMethodPriority}} | {{null}} | Priority of authentication methods. Is a list separated with comma. For example: {{Basic,Digest}} to exclude {{NTLM}}. |
| {{authUsername}} | {{null}} | Username for authentication |
| {{authPassword}} | {{null}} | Password for authentication |
| {{authDomain}} | {{null}} | Domain for NTML authentication |
| {{authHost}} | {{null}} | Optional host for NTML authentication |
| {{proxyHost}} | {{null}} | The proxy host name |
| {{proxyPort}} | {{null}} | The proxy port number |
| {{proxyAuthMethod}} | {{null}} | Authentication method for proxy, either as {{Basic}}, {{Digest}} or {{NTLM}}. |
| {{proxyAuthUsername}} | {{null}} | Username for proxy authentication |
| {{proxyAuthPassword}} | {{null}} | Password for proxy authentication |
| {{proxyAuthDomain}} | {{null}} | Domain for proxy NTML authentication |
| {{proxyAuthHost}} | {{null}} | Optional host for proxy NTML authentication |
{div}
When using authentication you *must* provide the choice of method for the {{authMethod}} or {{authProxyMethod}} options.
You can configure the proxy and authentication details on either the {{HttpComponent}} or the {{HttpEndoint}}. Values provided on the {{HttpEndpoint}} will take precedence over {{HttpComponent}}. Its most likely best to configure this on the {{HttpComponent}} which allows you to do this once.
The [Http] component uses convention over configuration which means that if you have not explicit set a {{authMethodPriority}} then it will fallback and use the select(ed) {{authMethod}} as priority as well. So if you use {{authMethod.Basic}} then the {{auhtMethodPriority}} will be {{Basic}} only.
h3. HttpComponent Options
{div:class=confluenceTableSmall}
|| Name || Default Value || Description ||
| {{httpBinding}} | {{null}} | To use a custom {{org.apache.camel.component.http.HttpBinding}}. |
| {{httpClientConfigurer}} | {{null}} | To use a custom {{org.apache.camel.component.http.HttpClientConfigurer}}. |
| {{httpConnectionManager}} | {{null}} | To use a custom {{org.apache.commons.httpclient.HttpConnectionManager}}. |
| {{httpConfiguration}} | {{null}} | To use a custom {{org.apache.camel.component.http.HttpConfiguration}} |
{div}
{{HttpConfiguration}} contains all the options listed in the table above under the section _HttpConfiguration - Setting Authentication and Proxy_.
h3. Message Headers
{div:class=confluenceTableSmall}
|| Name || Type || Description ||
| {{Exchange.HTTP_URI}} | {{String}} | URI to call. Will override existing URI set directly on the endpoint. |
| {{Exchange.HTTP_METHOD}} | {{String}} | HTTP Method / Verb to use (GET/POST/PUT/DELETE/HEAD/OPTIONS/TRACE) |
| {{Exchange.HTTP_PATH}} | {{String}} | Request URI's path, the header will be used to build the request URI with the HTTP_URI. *Camel 2.3.0:* 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}} | 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}}. |
| {{Exchange.HTTP_SERVLET_REQUEST}} | {{HttpServletRequest}} | The {{HttpServletRequest}} object. |
| {{Exchange.HTTP_SERVLET_RESPONSE}} | {{HttpServletResponse}} | The {{HttpServletResponse}} object. |
| {{Exchange.HTTP_PROTOCOL_VERSION}} | {{String}} | *Camel 2.5:* You can set the http protocol version with this header, eg. "HTTP/1.0". If you didn't specify the header, HttpProducer will use the default value "HTTP/1.1" |
{div}
The header name above are constants. For the spring DSL you have to use the value of the constant instead of the name.
h3. 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.
h3. 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 {{HttpOperationFailedException}} with the information.
- Response code is 400+, Camel regards it as an external server failure and will throw a {{HttpOperationFailedException}} with the information.
{tip:title=throwExceptionOnFailure}
The option, {{throwExceptionOnFailure}}, can be set to {{false}} to prevent the {{HttpOperationFailedException}} from being thrown for failed response codes. This allows you to get any response from the remote server.
There is a sample below demonstrating this.
{tip}
h3. HttpOperationFailedException
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
h3. 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.
h3. How to get access to HttpServletRequest and HttpServletResponse
You can get access to these two using the Camel type converter system using
{code}
HttpServletRequest request = exchange.getIn().getBody(HttpServletRequest.class);
HttpServletRequest response = exchange.getIn().getBody(HttpServletResponse.class);
{code}
h3. Using client tineout - SO_TIMEOUT
See the unit test in [this link|http://svn.apache.org/viewvc?view=rev&revision=781775]
h2. More Examples
h3. Configuring a Proxy
||Java DSL||
|{code}from("direct:start")
.to("http://oldhost?proxyHost=www.myproxy.com&proxyPort=80");
{code}|
There is also support for proxy authentication via the {{proxyUsername}} and {{proxyPassword}} options.
h4. Using proxy settings outside of URI
||Java DSL||Spring DSL||
|{code}
context.getProperties().put("http.proxyHost", "172.168.18.9");
context.getProperties().put("http.proxyPort" "8080");
{code}|{code}
<camelContext>
<properties>
<property key="http.proxyHost" value="172.168.18.9"/>
<property key="http.proxyPort" value="8080"/>
</properties>
</camelContext>
{code}|
Options on Endpoint will override options on the context.
h3. Configuring charset
If you are using {{POST}} to send data you can configure the {{charset}}
{code}
setProperty(Exchange.CHARSET_NAME, "iso-8859-1");
{code}
h3. Sample with scheduled poll
The sample polls the Google homepage every 10 seconds and write the page to the file {{message.html}}:
{code}
from("timer://foo?fixedRate=true&delay=0&period=10000")
.to("http://www.google.com")
.setHeader(FileComponent.HEADER_FILE_NAME, "message.html").to("file:target/google");
{code}
h3. Getting the Response Code
You can get the HTTP response code from the HTTP component by getting the value from the Out message header with {{HttpProducer.HTTP_RESPONSE_CODE}}.
{code:java}
Exchange exchange = template.send("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(HttpProducer.HTTP_RESPONSE_CODE, Integer.class);
{code}
h3. Using {{throwExceptionOnFailure=false}} to get any response back
In the route below we want to route a message that we [enrich|Content Enricher] with data returned from a remote HTTP call. As we want any response from the remote server, we set the {{throwExceptionOnFailure}} option to {{false}} so we get any response in the {{AggregationStrategy}}. As the code is based on a unit test that simulates a HTTP status code 404, there is some assertion code etc.
{snippet:id=e1|lang=java|url=camel/trunk/components/camel-jetty/src/test/java/org/apache/camel/component/jetty/JettySimplifiedHandle404Test.java}
h3. Disabling Cookies
To disable cookies you can set the HTTP Client to ignore cookies by adding this URI option:
{{httpClient.cookiePolicy=ignoreCookies}}
h3. Advanced Usage
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.
h4. Setting MaxConnectionsPerHost
The [Http] Component has a {{org.apache.commons.httpclient.HttpConnectionManager}} where you can configure various global configuration for the given component.
By global, we mean that any endpoint the component creates has the same shared {{HttpConnectionManager}}. So, if we want to set a different value for the max connection per host, we need to define it on the HTTP component and *not* on the endpoint URI that we usually use. So here comes:
First, we define the {{http}} component in Spring XML. Yes, we use the same scheme name, {{http}}, because otherwise Camel will auto-discover and create the component with default settings. What we need is to overrule this so we can set our options. In the sample below we set the max connection to 5 instead of the default of 2.
{snippet:id=e1|lang=xml|url=camel/tags/camel-2.2.0/tests/camel-itest/src/test/resources/org/apache/camel/itest/http/HttpMaxConnectionPerHostTest-context.xml}
And then we can just use it as we normally do in our routes:
{snippet:id=e2|lang=xml|url=camel/tags/camel-2.2.0/tests/camel-itest/src/test/resources/org/apache/camel/itest/http/HttpMaxConnectionPerHostTest-context.xml}
h4. Using preemptive authentication
An end user reported that he had problem with authenticating with HTTPS. The problem was eventually resolved when he discovered the HTTPS server did not return a HTTP code 401 Authorization Required. The solution was to set the following URI option: {{httpClient.authenticationPreemptive=true}}
h4. Accepting self signed certificates from remote server
See this [link|http://www.nabble.com/Using-HTTPS-in-camel-http-when-remote-side-has-self-signed-cert-td25916878.html] from a mailing list discussion with some code to outline how to do this with the Apache Commons HTTP API.
h4. Setting up SSL for HTTP Client
h5. Using the JSSE Configuration Utility
As of Camel 2.8, the HTTP4 component supports SSL/TLS configuration through the [Camel JSSE Configuration Utility|CAMEL:Camel Configuration Utilities]. 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.
The version of the Apache HTTP client used in this component resolves SSL/TLS information from a global "protocol" registry. This component provides an implementation, {{org.apache.camel.component.http.SSLContextParametersSecureProtocolSocketFactory}}, of the HTTP client's protocol socket factory in order to support the use of the Camel JSSE Configuration utility. The following example demonstrates how to configure the protocol registry and use the registered protocol information in a route.
{code}
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);
ProtocolSocketFactory factory =
new SSLContextParametersSecureProtocolSocketFactory(scp);
Protocol.registerProtocol("https",
new Protocol(
"https",
factory,
443));
from("direct:start")
.to("https://mail.google.com/mail/").to("mock:results");
{code}
h5. Configuring Apache HTTP Client Directly
Basically camel-http component is built on the top of Apache HTTP client, and you can implement a custom {{org.apache.camel.component.http.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:
{code}
Protocol authhttps = new Protocol("https", new AuthSSLProtocolSocketFactory(
new URL("file:my.keystore"), "mypassword",
new URL("file:my.truststore"), "mypassword"), 443);
Protocol.registerProtocol("https", authhttps);
{code}
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:
{code}
HttpComponent httpComponent = getContext().getComponent("http", HttpComponent.class);
httpComponent.setHttpClientConfigurer(new MyHttpClientConfigurer());
{code}
If you are doing this using the Spring DSL, you can specify your {{HttpClientConfigurer}} using the URI. For example:
{code}
<bean id="myHttpClientConfigurer"
class="my.https.HttpClientConfigurer">
</bean>
<to uri="https://myhostname.com:443/myURL?httpClientConfigurerRef=myHttpClientConfigurer"/>
{code}
As long as you implement the HttpClientConfigurer and configure your keystore and truststore as described above, it will work fine.
{include:Endpoint See Also}
- [Jetty]
|