12.2. Configuring a Consumer

12.2.1. Mechanisms for HTTP Consumer Endpoints

HTTP consumer endpoints can specify a number of HTTP connection attributes including whether the endpoint automatically accepts redirect responses, whether the endpoint can use chunking, whether the endpoint will request a keep-alive, and how the endpoint interacts with proxies. In addition to the HTTP connection properties, an HTTP consumer endpoint can specify how it is secured.
A consumer endpoint can be configured using two mechanisms:

12.2.2. Using Configuration

Namespace

The elements used to configure an HTTP consumer endpoint are defined in the namespace http://cxf.apache.org/transports/http/configuration. It is commonly referred to using the prefix http-conf. In order to use the HTTP configuration elements you must add the lines shown in Example 12.4, “HTTP Consumer Configuration Namespace” to the beans element of your endpoint's configuration file. In addition, you must add the configuration elements' namespace to the xsi:schemaLocation attribute.

Example 12.4. HTTP Consumer Configuration Namespace

<beans ...
       xmlns:http-conf="http://cxf.apache.org/transports/http/configuration"
       ...
       xsi:schemaLocation="...
                           http://cxf.apache.org/transports/http/configuration
                              http://cxf.apache.org/schemas/configuration/http-conf.xsd
                          ...">

Jetty runtime or Netty runtime

You can use the elements from the http-conf namespace to configure either the Jetty runtime or the Netty runtime.

The conduit element

You configure an HTTP consumer endpoint using the http-conf:conduit element and its children. The http-conf:conduit element takes a single attribute, name, that specifies the WSDL port element corresponding to the endpoint. The value for the name attribute takes the form portQName.http-conduit. Example 12.5, “http-conf:conduit Element” shows the http-conf:conduit element that would be used to add configuration for an endpoint that is specified by the WSDL fragment <port binding="widgetSOAPBinding" name="widgetSOAPPort> when the endpoint's target namespace is http://widgets.widgetvendor.net.

Example 12.5. http-conf:conduit Element

...
  <http-conf:conduit name="{http://widgets/widgetvendor.net}widgetSOAPPort.http-conduit">
    ...
  </http-conf:conduit>
...
The http-conf:conduit element has child elements that specify configuration information. They are described in Table 12.1, “Elements Used to Configure an HTTP Consumer Endpoint”.

Table 12.1. Elements Used to Configure an HTTP Consumer Endpoint

ElementDescription
http-conf:client
Specifies the HTTP connection properties such as timeouts, keep-alive requests, content types, etc. See the section called “The client element”.
http-conf:authorization
Specifies the parameters for configuring the basic authentication method that the endpoint uses preemptively.
The preferred approach is to supply a Basic Authentication Supplier object.
http-conf:proxyAuthorization
Specifies the parameters for configuring basic authentication against outgoing HTTP proxy servers.
http-conf:tlsClientParameters
Specifies the parameters used to configure SSL/TLS.
http-conf:basicAuthSupplier
Specifies the bean reference or class name of the object that supplies the basic authentication information used by the endpoint, either preemptively or in response to a 401 HTTP challenge.
http-conf:trustDecider
Specifies the bean reference or class name of the object that checks the HTTP(S) URLConnection object to establish trust for a connection with an HTTPS service provider before any information is transmitted.

The client element

The http-conf:client element is used to configure the non-security properties of a consumer endpoint's HTTP connection. Its attributes, described in Table 12.2, “HTTP Consumer Configuration Attributes”, specify the connection's properties.

Table 12.2. HTTP Consumer Configuration Attributes

AttributeDescription
ConnectionTimeout
Specifies the amount of time, in milliseconds, that the consumer attempts to establish a connection before it times out. The default is 30000.
0 specifies that the consumer will continue to send the request indefinitely.
ReceiveTimeout
Specifies the amount of time, in milliseconds, that the consumer will wait for a response before it times out. The default is 30000.
0 specifies that the consumer will wait indefinitely.
AutoRedirect
Specifies if the consumer will automatically follow a server issued redirection. The default is false.
MaxRetransmits
Specifies the maximum number of times a consumer will retransmit a request to satisfy a redirect. The default is -1 which specifies that unlimited retransmissions are allowed.
AllowChunking
Specifies whether the consumer will send requests using chunking. The default is true which specifies that the consumer will use chunking when sending requests.
Chunking cannot be used if either of the following are true:
  • http-conf:basicAuthSupplier is configured to provide credentials preemptively.
  • AutoRedirect is set to true.
In both cases the value of AllowChunking is ignored and chunking is disallowed.
Accept
Specifies what media types the consumer is prepared to handle. The value is used as the value of the HTTP Accept property. The value of the attribute is specified using multipurpose internet mail extensions (MIME) types.
AcceptLanguage
Specifies what language (for example, American English) the consumer prefers for the purpose of receiving a response. The value is used as the value of the HTTP AcceptLanguage property.
Language tags are regulated by the International Organization for Standards (ISO) and are typically formed by combining a language code, determined by the ISO-639 standard, and country code, determined by the ISO-3166 standard, separated by a hyphen. For example, en-US represents American English.
AcceptEncoding
Specifies what content encodings the consumer is prepared to handle. Content encoding labels are regulated by the Internet Assigned Numbers Authority (IANA). The value is used as the value of the HTTP AcceptEncoding property.
ContentType
Specifies the media type of the data being sent in the body of a message. Media types are specified using multipurpose internet mail extensions (MIME) types. The value is used as the value of the HTTP ContentType property. The default is text/xml.
For web services, this should be set to text/xml. If the client is sending HTML form data to a CGI script, this should be set to application/x-www-form-urlencoded. If the HTTP POST request is bound to a fixed payload format (as opposed to SOAP), the content type is typically set to application/octet-stream.
Host
Specifies the Internet host and port number of the resource on which the request is being invoked. The value is used as the value of the HTTP Host property.
This attribute is typically not required. It is only required by certain DNS scenarios or application designs. For example, it indicates what host the client prefers for clusters (that is, for virtual servers mapping to the same Internet protocol (IP) address).
Connection
Specifies whether a particular connection is to be kept open or closed after each request/response dialog. There are two valid values:
  • Keep-Alive — Specifies that the consumer wants the connection kept open after the initial request/response sequence. If the server honors it, the connection is kept open until the consumer closes it.
  • close(default) — Specifies that the connection to the server is closed after each request/response sequence.
CacheControl
Specifies directives about the behavior that must be adhered to by caches involved in the chain comprising a request from a consumer to a service provider. See Section 12.2.4, “Consumer Cache Control Directives”.
Cookie
Specifies a static cookie to be sent with all requests.
BrowserType
Specifies information about the browser from which the request originates. In the HTTP specification from the World Wide Web consortium (W3C) this is also known as the user-agent. Some servers optimize based on the client that is sending the request.
Referer
Specifies the URL of the resource that directed the consumer to make requests on a particular service. The value is used as the value of the HTTP Referer property.
This HTTP property is used when a request is the result of a browser user clicking on a hyperlink rather than typing a URL. This can allow the server to optimize processing based upon previous task flow, and to generate lists of back-links to resources for the purposes of logging, optimized caching, tracing of obsolete or mistyped links, and so on. However, it is typically not used in web services applications.
If the AutoRedirect attribute is set to true and the request is redirected, any value specified in the Referer attribute is overridden. The value of the HTTP Referer property is set to the URL of the service that redirected the consumer’s original request.
DecoupledEndpoint
Specifies the URL of a decoupled endpoint for the receipt of responses over a separate provider->consumer connection. For more information on using decoupled endpoints see, Section 12.6, “Using the HTTP Transport in Decoupled Mode”.
You must configure both the consumer endpoint and the service provider endpoint to use WS-Addressing for the decoupled endpoint to work.
ProxyServer
Specifies the URL of the proxy server through which requests are routed.
ProxyServerPort
Specifies the port number of the proxy server through which requests are routed.
ProxyServerType
Specifies the type of proxy server used to route requests. Valid values are:
  • HTTP(default)
  • SOCKS

Example

Example 12.6, “HTTP Consumer Endpoint Configuration” shows the configuration of an HTTP consumer endpoint that wants to keep its connection to the provider open between requests, that will only retransmit requests once per invocation, and that cannot use chunking streams.

Example 12.6. HTTP Consumer Endpoint Configuration

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:http-conf="http://cxf.apache.org/transports/http/configuration"
       xsi:schemaLocation="http://cxf.apache.org/transports/http/configuration
                             http://cxf.apache.org/schemas/configuration/http-conf.xsd
                           http://www.springframework.org/schema/beans
                             http://www.springframework.org/schema/beans/spring-beans.xsd">
   
  <http-conf:conduit name="{http://apache.org/hello_world_soap_http}SoapPort.http-conduit">
    <http-conf:client Connection="Keep-Alive"
                      MaxRetransmits="1"
                      AllowChunking="false" />
  </http-conf:conduit>
</beans>

More information

For more information on HTTP conduits see Appendix B, Conduits.

12.2.3. Using WSDL

Namespace

The WSDL extension elements used to configure an HTTP consumer endpoint are defined in the namespace http://cxf.apache.org/transports/http/configuration. It is commonly referred to using the prefix http-conf. In order to use the HTTP configuration elements you must add the line shown in Example 12.7, “HTTP Consumer WSDL Element's Namespace” to the definitions element of your endpoint's WSDL document.

Example 12.7. HTTP Consumer WSDL Element's Namespace

<definitions ...
       xmlns:http-conf="http://cxf.apache.org/transports/http/configuration"

Jetty runtime or Netty runtime

You can use the elements from the http-conf namespace to configure either the Jetty runtime or the Netty runtime.

The client element

The http-conf:client element is used to specify the connection properties of an HTTP consumer in a WSDL document. The http-conf:client element is a child of the WSDL port element. It has the same attributes as the client element used in the configuration file. The attributes are described in Table 12.2, “HTTP Consumer Configuration Attributes”.

Example

Example 12.8, “WSDL to Configure an HTTP Consumer Endpoint” shows a WSDL fragment that configures an HTTP consumer endpoint to specify that it does not interact with caches.

Example 12.8. WSDL to Configure an HTTP Consumer Endpoint

<service ... >
  <port ... >
    <soap:address ... />
    <http-conf:client CacheControl="no-cache" />
  </port>
</service>

12.2.4. Consumer Cache Control Directives

Table 12.3, “http-conf:client Cache Control Directives” lists the cache control directives supported by an HTTP consumer.

Table 12.3. http-conf:client Cache Control Directives

DirectiveBehavior
no-cache
Caches cannot use a particular response to satisfy subsequent requests without first revalidating that response with the server. If specific response header fields are specified with this value, the restriction applies only to those header fields within the response. If no response header fields are specified, the restriction applies to the entire response.
no-store
Caches must not store either any part of a response or any part of the request that invoked it.
max-age
The consumer can accept a response whose age is no greater than the specified time in seconds.
max-stale
The consumer can accept a response that has exceeded its expiration time. If a value is assigned to max-stale, it represents the number of seconds beyond the expiration time of a response up to which the consumer can still accept that response. If no value is assigned, the consumer can accept a stale response of any age.
min-fresh
The consumer wants a response that is still fresh for at least the specified number of seconds indicated.
no-transform
Caches must not modify media type or location of the content in a response between a provider and a consumer.
only-if-cached
Caches should return only responses that are currently stored in the cache, and not responses that need to be reloaded or revalidated.
cache-extension
Specifies additional extensions to the other cache directives. Extensions can be informational or behavioral. An extended directive is specified in the context of a standard directive, so that applications not understanding the extended directive can adhere to the behavior mandated by the standard directive.