6.2. Consumer Configuration
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 6.4, “HTTP Consumer WSDL Element's Namespace” to the definitions element of your endpoint's WSDL document.
Example 6.4. HTTP Consumer WSDL Element's Namespace
<definitions ...
xmlns:http-conf="http://cxf.apache.org/transports/http/configuration"Configuring the endpoint
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. The attributes are described in Table 6.1, “HTTP Consumer Configuration Attributes”.
| Attribute | Description |
|---|---|
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:
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:
|
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 the section called “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 6.4, “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:
|
Consumer Cache Control Directives
Table 6.2, “
http-conf:client Cache Control Directives” lists the cache control directives supported by an HTTP consumer.
| Directive | Behavior |
|---|---|
| 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.
|
Example
Example 6.5, “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 6.5. WSDL to Configure an HTTP Consumer Endpoint
<service ... >
<port ... >
<soap:address ... />
<http-conf:client CacheControl="no-cache" />
</port>
</service>