org.eclipse.californium.proxy

Class HttpTranslator

java.lang.Object

org.eclipse.californium.proxy.HttpTranslator

public final class HttpTranslator
extends java.lang.Object

Class providing the translations (mappings) from the HTTP message representations to the CoAP message representations and vice versa.

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Properties	HTTP_TRANSLATION_PROPERTIES Property file containing the mappings between coap messages and http messages.
static int	STATUS_NOT_FOUND
static int	STATUS_TIMEOUT
static int	STATUS_TRANSLATION_ERROR
static int	STATUS_URI_MALFORMED
static int	STATUS_WRONG_METHOD

Method Summary

Modifier and Type	Method and Description
static Request	createCoapRequestDiscovery(java.lang.String proxyUri)
static Request	createCoapRequestOptions(java.lang.String proxyUri)
static int	getCoapMediaType(org.apache.http.HttpMessage httpMessage) Gets the coap media type associated to the http entity.
static java.util.List<Option>	getCoapOptions(org.apache.http.Header[] headers) Gets the coap options starting from an array of http headers.
static byte[]	getCoapPayload(org.apache.http.HttpEntity httpEntity) Method to map the http entity of a http message in a coherent payload for the coap message.
static Request	getCoapRequest(org.apache.http.HttpRequest httpRequest, java.lang.String proxyResource, boolean proxyingEnabled) Gets the coap request.
static Response	getCoapResponse(org.apache.http.HttpResponse httpResponse, Request coapRequest) Gets the CoAP response from an incoming HTTP response.
static void	getHttpDiscovery(org.apache.http.HttpRequest httpRequest, Response coapResponse, org.apache.http.HttpResponse httpResponse)
static org.apache.http.HttpEntity	getHttpEntity(Message coapMessage) Generates an HTTP entity starting from a CoAP request.
static org.apache.http.Header[]	getHttpHeaders(java.util.List<Option> optionList, java.lang.String host) Gets the http headers from a list of CoAP options.
static void	getHttpOptions(org.apache.http.HttpRequest httpRequest, Response coapResponse, org.apache.http.HttpResponse httpResponse)
static org.apache.http.HttpRequest	getHttpRequest(Request coapRequest) Gets the http request starting from a CoAP request.
static void	getHttpResponse(org.apache.http.HttpRequest httpRequest, Response coapResponse, org.apache.http.HttpResponse httpResponse) Sets the parameters of the incoming http response from a CoAP response.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HTTP_TRANSLATION_PROPERTIES

public static final java.util.Properties HTTP_TRANSLATION_PROPERTIES

Property file containing the mappings between coap messages and http messages.

STATUS_TIMEOUT

public static final int STATUS_TIMEOUT

See Also:

Constant Field Values

STATUS_NOT_FOUND

public static final int STATUS_NOT_FOUND

See Also:

Constant Field Values

STATUS_TRANSLATION_ERROR

public static final int STATUS_TRANSLATION_ERROR

See Also:

Constant Field Values

STATUS_URI_MALFORMED

public static final int STATUS_URI_MALFORMED

See Also:

Constant Field Values

STATUS_WRONG_METHOD

public static final int STATUS_WRONG_METHOD

See Also:

Constant Field Values

Method Detail

getCoapMediaType

public static int getCoapMediaType(org.apache.http.HttpMessage httpMessage)

Gets the coap media type associated to the http entity. Firstly, it looks for a valid mapping in the property file. If this step fails, then it tries to explicitly map/parse the declared mime/type by the http entity. If even this step fails, it sets application/octet-stream as content-type.

Parameters:

httpMessage -

Returns:

the coap media code associated to the http message entity. * @see HttpHeader, ContentType, MediaTypeRegistry

getCoapOptions

public static java.util.List<Option> getCoapOptions(org.apache.http.Header[] headers)

Gets the coap options starting from an array of http headers. The content-type is not handled by this method. The method iterates over an array of headers and for each of them tries to find a mapping in the properties file, if the mapping does not exists it skips the header ignoring it. The method handles separately certain headers which are translated to options (such as accept or cache-control) whose content should be semantically checked or requires ad-hoc translation. Otherwise, the headers content is translated with the appropriate format required by the mapped option.

Parameters:

headers -

getCoapPayload

public static byte[] getCoapPayload(org.apache.http.HttpEntity httpEntity)
                             throws TranslationException

Method to map the http entity of a http message in a coherent payload for the coap message. The method simply gets the bytes from the entity and, if needed changes the charset of the obtained bytes to UTF-8.

Parameters:

httpEntity - the http entity

Returns:

byte[]

Throws:

TranslationException - the translation exception

getCoapRequest

public static Request getCoapRequest(org.apache.http.HttpRequest httpRequest,
                                     java.lang.String proxyResource,
                                     boolean proxyingEnabled)
                              throws TranslationException

Gets the coap request. Creates the CoAP request from the HTTP method and mapping it through the properties file. The uri is translated using regular expressions, the uri format expected is either the embedded mapping (http://proxyname.domain:80/proxy/coapserver:5683/resource converted in coap://coapserver:5683/resource) or the standard uri to indicate a local request not to be forwarded. The method uses a decoder to translate the application/x-www-form-urlencoded format of the uri. The CoAP options are set translating the headers. If the HTTP message has an enclosing entity, it is converted to create the payload of the CoAP message; finally the content-type is set accordingly to the header and to the entity type.

Parameters:

httpRequest - the http request

proxyResource - the proxy resource, if present in the uri, indicates the need of forwarding for the current request

proxyingEnabled - TODO

Returns:

the coap request * @throws TranslationException the translation exception

Throws:

TranslationException

createCoapRequestDiscovery

public static Request createCoapRequestDiscovery(java.lang.String proxyUri)
                                          throws TranslationException

Throws:

TranslationException

createCoapRequestOptions

public static Request createCoapRequestOptions(java.lang.String proxyUri)
                                        throws TranslationException

Throws:

TranslationException

getCoapResponse

public static Response getCoapResponse(org.apache.http.HttpResponse httpResponse,
                                       Request coapRequest)
                                throws TranslationException

Gets the CoAP response from an incoming HTTP response. No null value is returned. The response is created from a the mapping of the HTTP response code retrieved from the properties file. If the code is 204, which has multiple meaning, the mapping is handled looking on the request method that has originated the response. The options are set thorugh the HTTP headers and the option max-age, if not indicated, is set to the default value (60 seconds). if the response has an enclosing entity, it is mapped to a CoAP payload and the content-type of the CoAP message is set properly.

Parameters:

httpResponse - the http response

coapRequest -

Returns:

the coap response * @throws TranslationException the translation exception

Throws:

TranslationException

getHttpEntity

public static org.apache.http.HttpEntity getHttpEntity(Message coapMessage)
                                                throws TranslationException

Generates an HTTP entity starting from a CoAP request. If the coap message has no payload, it returns a null http entity. It takes the payload from the CoAP message and encapsulates it in an entity. If the content-type is recognized, and a mapping is present in the properties file, it is translated to the correspondent in HTTP, otherwise it is set to application/octet-stream. If the content-type has a charset, namely it is printable, the payload is encapsulated in a StringEntity, if not it a ByteArrayEntity is used.

Parameters:

coapMessage - the coap message

Returns:

null if the request has no payload * @throws TranslationException the translation exception

Throws:

TranslationException

getHttpHeaders

public static org.apache.http.Header[] getHttpHeaders(java.util.List<Option> optionList,
                                                      java.lang.String host)

Gets the http headers from a list of CoAP options. The method iterates over the list looking for a translation of each option in the properties file, this process ignores the proxy-uri and the content-type because they are managed differently. If a mapping is present, the content of the option is mapped to a string accordingly to its original format and set as the content of the header.

Parameters:

optionList - the coap message

Returns:

Header[]

getHttpRequest

public static org.apache.http.HttpRequest getHttpRequest(Request coapRequest)
                                                  throws TranslationException

Gets the http request starting from a CoAP request. The method creates the HTTP request through its request line. The request line is built with the uri coming from the string representing the CoAP method and the uri obtained from the proxy-uri option. If a payload is provided, the HTTP request encloses an HTTP entity and consequently the content-type is set. Finally, the CoAP options are mapped to the HTTP headers.

Parameters:

coapRequest - the coap request

Returns:

the http request * @throws TranslationException the translation exception * @throws URISyntaxException the uRI syntax exception

Throws:

TranslationException

getHttpResponse

public static void getHttpResponse(org.apache.http.HttpRequest httpRequest,
                                   Response coapResponse,
                                   org.apache.http.HttpResponse httpResponse)
                            throws TranslationException

Sets the parameters of the incoming http response from a CoAP response. The status code is mapped through the properties file and is set through the StatusLine. The options are translated to the corresponding headers and the max-age (in the header cache-control) is set to the default value (60 seconds) if not already present. If the request method was not HEAD and the coap response has a payload, the entity and the content-type are set in the http response.

Parameters:

coapResponse - the coap response

httpResponse -

httpRequest - HttpRequest

Throws:

TranslationException - the translation exception

getHttpDiscovery

public static void getHttpDiscovery(org.apache.http.HttpRequest httpRequest,
                                    Response coapResponse,
                                    org.apache.http.HttpResponse httpResponse)

getHttpOptions

public static void getHttpOptions(org.apache.http.HttpRequest httpRequest,
                                  Response coapResponse,
                                  org.apache.http.HttpResponse httpResponse)