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Available as of Camel 2.3
The The camel-http4
: component provides HTTP based endpoints for calling 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:
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<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> |
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Camel |
URI
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Format
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http4:hostname[:port][/resourceUri][?options] |
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Default Ports
80
forHTTP
443
forHTTPS
.
Specifying Options
Options should be passed on the URI's query string using You can append query options to the URI in the following format, : ?option=value&option=value&...
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You can only produce to endpoints generated by the HTTP4 the |
HttpComponent
Options
Name | Default Value | Description |
---|---|---|
|
| The maximum number of connections. |
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| The maximum number of connections per route. |
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| Camel 2.11.2/2.12.0: To use a custom Note: if |
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| Reference to a |
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| To use a custom |
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| To use a custom |
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| Camel 2.9.2: To use a custom |
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| Camel 2.8: To use a custom NoteImportant: Only only one instance of See further below for more details. |
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| Camel 2.7: You can refer to a different |
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| Camel 2.11.0: The time for connection to live, the time unit is millisecond, the default value is always keep alive. |
...
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HttpEndpoint Options
| Camel 2.16.1/2.15.5: Whether to allow java serialization when a request uses |
HttpEndpoint
Options
Name | Default Value | Description | |||||
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| Option to disable throwing the | |||||
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| If If Also, if | |||||
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| 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. | |||||
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| Camel 2.11.2/2.12.0: To use a custom Note: if | |||||
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From Camel 2.17: this option is also supported by the producer to allow the use of a response stream directly instead of stream caching as by default. | |||||
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| Camel 2.10.4: Reference to a instance of | |||||
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Name | Default Value | Description | |||||
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| Option to disable throwing the | |||||
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| 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". | |||||
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| 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. | |||||
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| Camel 2.11.2/2.12.0: To use a custom | |||||
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| 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. | |||||
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| Camel 2.10.4: Reference to a instance of | |||||
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| Deprecated and will be removed in Camel 3.0: Reference to a | |||||
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| To use a custom | |||||
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| Deprecated and will be removed in Camel 3.0: Reference to a | |||||
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| Reference to a | |||||
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| Deprecated and will be removed in Camel 3.0:Camel 2.9.2: Reference to a custom | |||||
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| Camel 2.9.2: To use a custom | |||||
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| Setting options on the BasicHttpParams. For instance Since Camel 2.13.0: httpClient is changed to configure the HttpClientBuilder and RequestConfig.Builder, please check out API document for a complete reference. E.g. since this version use |
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| Reference to a | |||||
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| Camel 2.9.2: |
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| To use a custom | ||
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| If enabled and an Exchange failed processing on the consumer side, and if the caused | |||||
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| Deprecated and will be removed in Camel 3.0: Camel 2.8: Reference to a | |||||
| Setting options on the BasicHttpParams. For instance From Camel 2.13.0: | ||||||
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| To use a custom | |||||
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| If On the producer side the exception will be deserialized and thrown as is, instead of the | |||||
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| Camel 2.11.1 | ||
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| Camel 2.11.71: You can refer Reference to a different |
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| Note: only one instance of |
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| Camel 2.14: The maximum number of total connections that the connection manager has. If this option is not set, camel will use the component's setting instead. | |||||
See below for more details. | |||||||
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| Camel 2.7: You can refer to a different | |||||
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| Camel 2.11: Producer only Refers to a custom For more details see UrlRewrite and How to use Camel as a HTTP proxy between a client and server. | |||||
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| Camel 2.14: The maximum number of total connections that the connection manager has. If this option | 14: The maximum number of connections per route. If this option is not set, camel will use the component's setting instead. | ||||
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| Camel 2.14: The maximum number of connections per route. If this option is not set, camel will use the component's setting instead. | |||||
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| Camel 2.11.11.3/2.12.2: If this option is true, | |||||
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| Camel 2.16: Consumer only Whether to eager check whether the HTTP requests has content if the content-length header is 0 or not present. This can be turned on in case HTTP clients do not send streamed data. | |||||
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| Camel 2.16: If this option is true thenthen to propagating | |||||
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| Camel 2.16: The status codes which is considered a success response. The values are inclusive. The range must be defined as from-to with the dash included. | |||||
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| Camel 2.16: If this option is true, The | http HTTP producer won't read response body and cache the input stream. |
The following authentication options can also be set on the HttpEndpoint:
Setting Basic Authentication and Proxy
Before Camel 2.8.0
Name | Default Value | Description |
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| Username for authentication. |
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| Password for authentication. |
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| The domain name for authentication. |
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| The host name authentication. |
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| The proxy host name |
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| The proxy port number |
|
| Username for proxy authentication |
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| Password for proxy authentication |
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| The proxy domain name |
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| The proxy Nt host name |
Since Camel 2.8.0
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| Camel 2.18: If this option is true, The HTTP client will use System Properties to set some parameters of his configuration |
mapHttpMessageBody |
| Camel 2.18: If this option is true then |
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| Camel 2.18: If this option is true then |
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| Camel 2.18: If this option is true then |
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| Camel 2.18: If this option is true, the producer will add a Connection Close header to HTTP Request |
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| Camel 2.19: Configure a cookie handler to maintain a HTTP session |
Setting Basic Authentication and Proxy
The following authentication options can also be set on the HttpEndpoint
:
Before Camel 2.8.0:
Name | Default Value | Description |
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|
| The domain name for authentication. |
|
| The host name authentication. |
|
| Password for authentication. |
|
| Username for authentication. |
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Name | Default Value | Description |
|
| Username for authentication |
|
| Password for authentication |
|
| The domain name for authentication |
|
| The host name authentication |
|
| The proxy host name |
|
| The proxy port number |
|
| Username for proxy authentication |
|
| Password for proxy authentication |
|
| The proxy domain name |
|
| The proxy Nt host name |
From Camel 2.8.0:
Name | Default Value | Description |
---|---|---|
|
| The domain name for authentication |
|
| The host name authentication |
|
| Password for authentication |
|
| Username for authentication |
|
| The proxy host name |
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| The proxy port number |
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| The proxy scheme, will fallback and use the scheme from the endpoint if not configured. |
|
| Username for proxy authentication |
|
| Password for proxy authentication |
|
| The proxy domain name |
|
| The proxy Nt host name |
Message Headers
Name | Type | Description |
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|
| The HTTP content encoding. Is set on both the |
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| The HTTP content type. Is set on both the |
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| Character encoding. |
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| Request URI's path. The header will be used to build the request URI with the |
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| URI parameters. Will override existing URI parameters set directly on the endpoint. |
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| The HTTP response code from the external server. Is |
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| The HTTP response text from the external server. |
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| The URI to call. The value of this option will override the existing URI that's set directly on the endpoint. It's not the same as the Camel endpoint URI, where you can configure endpoint options such as security etc. This header does not support that, it's only the URI of the HTTP server. |
Before setting the above, you may wish to read How to avoid sending some or all message headers to prevent inadvertent data "leaks" from your application.
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,
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proxyAuthUsername
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null
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Username for proxy authentication
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proxyAuthPassword
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null
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Password for proxy authentication
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proxyAuthDomain
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null
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The proxy domain name
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proxyAuthNtHost
...
null
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The proxy Nt host name
so headers are preserved during routing. Additionally Camel will add the HTTP response headers as well to the OUT
message headers.
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When
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Response Code
Message Headers
Name | Type | Description |
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| URI to call. Will override existing URI set directly on the endpoint. |
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| Request URI's path, the header will be used to build the request URI with the HTTP_URI. |
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| URI parameters. Will override existing URI parameters set directly on the endpoint. |
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| The HTTP response code from the external server. Is 200 for OK. |
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| Character encoding. |
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| The HTTP content type. Is set on both the IN and OUT message to provide a content type, such as |
|
| The HTTP content encoding. Is set on both the IN and OUT message to provide a content encoding, such as |
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.
...
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 aHttpOperationFailedException
with the information. Response code is
400+
, Camel regards it as an external server failure and will throw aHttpOperationFailedException
with the information.Tip title throwExceptionOnFailure The option,
throwExceptionOnFailure
, can be set tofalse
to prevent theHttpOperationFailedException
from being IfthrowExceptionOnFailure=false
theHttpOperationFailedException
will not be thrown for failed response codes. This allows you to get any response from the remote server.
There is a sample below demonstrating this.
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.
Calling using using GET
or or POST
The following algorithm is used to determine whether the GET
or POST
HTTP method should be used: 1.
- Use the method provided in the header.
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GET
if query string is provided in the header.
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GET
if endpoint is configured with a query string.
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POST
if there is data to send (body is not null).
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GET
otherwise.
How to
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Access The HttpServletRequest
and HttpServletResponse
You can get access to these two using the Camel type converter system using
NOTE You
Info |
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Note: you can get the request and response not just from the processor after |
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the camel-jetty |
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or camel-cxf endpoint. |
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HttpServletRequest request = exchange.getIn().getBody(HttpServletRequest.class); HttpServletRequest response = exchange.getIn().getBody(HttpServletResponse.class); |
Configuring URI to
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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.
Java DSL:
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from("direct:start") .to("http4://oldhost"); |
And the equivalent Spring sampleDSL:
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<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.:
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from("direct:start") .setHeader(Exchange.HTTP_URI, constant("http://newhost")) .to("http4://oldhost"); |
In the sample above Camel will call the the http://newhost
despite the endpoint is configured with http4://oldhost
.
If the the camel-http4
endpoint is working in bridge mode, it will ignore the message header of Exchange.HTTP_URI
.
Configuring URI Parameters
The http The camel-http4
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.:
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from("direct:start") .to("http4://oldhost?order=123&detail=short"); |
Or options provided in via a header:
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from("direct:start") .setHeader(Exchange.HTTP_QUERY, constant("order=123&detail=short")) .to("http4://oldhost"); |
How
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To Set The HTTP Method ( GET
/ PATCH
/ POST
/ PUT
/ DELETE
/ HEAD
/ OPTIONS
/ TRACE
)
...
on the HTTP
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Producer
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The http HTTP |
The HTTP4 component provides a way to set the The camel-http4
specifies the particular HTTP request method by setting the message header. Here is an examplevia a header:
Example:
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from("direct:start") .setHeader(Exchange.HTTP_METHOD, constant(org.apache.camel.component.http4.HttpMethods.POST)) .to("http4://www.google.com") .to("mock:results"); |
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.setHeader("CamelHttpMethod", constant("POST")) |
And the equivalent Spring sampleDSL:
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<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> |
Using
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Client Timeout - SO_TIMEOUT
See the HttpSOTimeoutTest unit test. Since From Camel 2.13.0: See the updated HttpSOTimeoutTest unit test.
Configuring a Proxy
The HTTP4 The camel-http4
component provides a way to configure a proxy.
...
There is also support for proxy authentication via the proxyAuthUsername
and proxyAuthPassword
options.
Using
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Proxy Settings Outside of the URI
To avoid System properties conflicts, you can set proxy configuration only from the the CamelContext
or URI.
Java DSL:
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context.getProperties().put("http.proxyHost", "172.168.18.9"); context.getProperties().put("http.proxyPort" "8080"); |
Spring XMLDSL:
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<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 or CamelContext
Properties and then the endpoint proxy options if provided.
So you can override the system properties with the endpoint options.Notice
Info |
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Note: in Camel 2.8 there is also a http.proxyScheme property you can set to explicit configure the scheme to use. |
Configuring Configuring charset
If you are using POST
to send data you can configure the charset
using the Exchange
property:
Code Block | ||
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exchange.setProperty(Exchange.CHARSET_NAME, "ISO-8859-1"); |
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Example: Using a Scheduled Poll
This sample polls the Google homepage every 10 seconds and write the page to the file message.html
:
Code Block | ||
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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"); |
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.
Code Block | ||||
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// we query for Camel at the Google page template.sendBody("http4://www.google.com/search?q=Camel", null); |
URI Parameters
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From the Message
Code Block | ||||
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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("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.
Getting the Response Code
You can get the HTTP response code from the HTTP4 the camel-http4
component by getting the value from the Out the OUT
message header with Exchange.HTTP_RESPONSE_CODE
.
Code Block | ||||
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Exchange exchange = template.send("http4://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);
|
...
To disable cookies you can set the HTTP Client to ignore cookies by adding this URI option: httpClient.cookiePolicy=ignoreCookies
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.
...
Using the JSSE Configuration Utility
As of From Camel 2.8, the HTTP4 : the camel-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 the camel-http4
component.
Programmatic
...
Configuration of the
...
Component
Code Block | ||
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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("https4", HttpComponent.class); httpComponent.setSslContextParameters(scp); |
Spring DSL
...
Based Configuration of
...
Endpoint
Code Block | ||||
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... <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"/>... |
Configuring Apache HTTP Client Directly
Basically Basically camel-http4
component is built on the top of Apache HttpClient. Please refer to 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 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:
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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 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:
...
If you are doing this using the Spring DSL, you can specify your HttpClientConfigurer
using the URI. For example
Example:
Code Block | ||
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| ||
<bean id="myHttpClientConfigurer" class="my.https.HttpClientConfigurer"> </bean> <to uri="https4://myhostname.com:443/myURL?httpClientConfigurer=myHttpClientConfigurer"/> |
As long as you implement the 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 HttpContext
's:
Code Block | ||
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| ||
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 an HttpContext
in the Spring application context file:
...
3. Reference the context in the the http4
URL:
Code Block | ||
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| ||
<to uri="https4://myhostname.com:443/myURL?httpContext=myHttpContext"/> |
Using
...
Different SSLContextParameters
The HTTP4 component only support one instance of org.apache.camel.util.jsse.SSLContextParameters
per component. If you need to use 2 two or more different instances, then you need to setup multiple HTTP4 components as shown below. Where we have 2 two components, each using their own instance of sslContextParameters
property.
Code Block | ||||
---|---|---|---|---|
| ||||
<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> |