In some mapping programs it may be necessary to access fields in the message header. For this purpose, the mapping runtime saves the field values as key-value pairs.
Examples of Key-Value Pairs in the Map for Runtime Constants
Key |
Value |
MessageClass |
ApplicationMessage |
ProcessingMode |
synchronous |
ReceiverNamespace |
http://com.sap/xi/example |
The keys are derived from the field names of the fields in the message header.
To be able to read the fields of the message header at runtime, you must access the map for the runtime constants. However, if you were to access the map by using the keys specified above and one of the keys were to change, the program code would be rendered invalid. For this reason, the mapping API provides string constants that can be used to access the map in place of the keys.
String Constants for Accessing the Runtime Constants in the Map
String Constant |
Key |
MESSAGE_CLASS |
MessageClass |
VERSION_MAJOR |
VersionMajor |
VERSION_MINOR |
„VersionMinor“ |
PROCESSING_MODE |
„ProcessingMode“ |
MESSAGE_ID |
„MessageId“ |
REF_TO_MESSAGE_ID |
„RefToMessageId“ |
CONVERSATION_ID |
„ConversionId“ |
TIME_SENT |
„TimeSent“ |
INTERFACE |
„Interface“ |
INTERFACE_NAMESPACE |
„InterfaceNamespace“ |
SENDER_PARTY |
„SenderParty“ |
SENDER_PARTY_AGENCY |
„SenderPartyAgency“ |
SENDER_PARTY_SCHEME |
„SenderPartyScheme“ |
SENDER_SERVICE |
„SenderService“ |
RECEIVER_NAME |
„ReceiverName“ |
RECEIVER_NAMESPACE |
„ReceiverNamespace“ |
RECEIVER_PARTY |
„ReceiverParty“ |
RECEIVER_PARTY_AGENCY |
„ReceiverPartyAgency“ |
RECEIVER_PARTY_SCHEME |
„ReceiverPartyScheme“ |
RECEIVER_SERVICE |
„ReceiverService“ |
MAPPING_TRACE |
„MappingTrace“ |
How the access works varies according to where you want to query the runtime constants:
● In Java mappings you work with the get-methods of the mapping API.
● Within a user-defined function of a message mapping, you can access the map either by using the method getTransformationParameters() of the container object or by using the method getParameters() of the GlobalContainer object. See: Container Object.
● If you are still working with the SAP NetWeaver 2004/SAP NetWeaver 7.0 JAVA mapping API, you must code the method setParameter within a JAVA mapping to be able to access the map. More information: Java-Mapping-API (SAP NetWeaver 2004 and 7.0).
In certain exceptional and unavoidable cases, it may be necessary to use the keys to access the fields in the message header. This is always the case when you want to access the contents of the map by means of a variable. In the example below, a variable key key, which is to be used to read a field in the message header, is transferred to a user-defined function of a message mapping. You can only use a variable to access the map if the variable has the name of the key as its value and not the name of the string constant.
String headerField;
java.util.Map map;
// get runtime constant map
map = container.getTransformationParameters();
// get value of header field by using variable key
headerField = (String) map.get(key);
For example, to read the message ID from the message header, the variable key must have the value MessageId and not MESSAGE_ID.
Since the new mapping API works with get-methods, you can only access the message header in this way when you are using the SAP NetWeaver 2004 and 7.0 JAVA mapping API.