WebSphere MQ Integrator Broker 2.1 中健壮的错误处理: 附录

从异常列表中抽取诊断信息的代码。为了说明清楚，我们提供了适当的注释。注释由“--”开始。
-- Enter SQL below this line.  SQL above this line might be regenerated,
-- causing any modifications to be lost.
-- This Variable determines whether Specific or General Diagnostic
-- Information is generated.
DECLARE IsSpecific Boolean;
-- Can be dynamically set using the Environment Variable.
SET IsSpecific = True;
DECLARE I Integer;
DECLARE J Integer;
SET J = CARDINALITY("InputRoot".*[]);
SET I = 1;
-- Copying(Properties,MQMD,other headers) the Message Tree except for
-- the Body to the Output.
While I < J do
SET OutputRoot.*[I] = InputRoot.*[I];
SET I=I+1;
End While;
-- Sets the Output Diagnostic Message's Format to be XML.
SET "OutputRoot"."Properties"."MessageFormat" = 'XML';
SET OutputRoot.MQMD.Expiry = -1;
-- Source of the message, which caused the error.
SET OutputRoot.XML.Error.MessageSource.QueueManager =
  "InputRoot".MQMD.ReplyToQMgr;
SET OutputRoot.XML.Error.MessageSource.Queue =
  "InputRoot".MQMD.SourceQueue;
-- If isSpecific is True Specific Diagnostic Information is Generated.
If IsSpecific = True then
-- Point to the First Child to the ExceptionList Root.
DECLARE Location character;
DECLARE Diagnostics character;
DECLARE DiagnosticsInfo character;
DECLARE Width Integer;
SET Width = 1;
DECLARE Path REFERENCE TO InputExceptionList.*[Width];
-- Check whether the Width of the Exception Tree is more and Proceed.
While LastMove(Path) do
SET Diagnostics = '';
SET DiagnosticsInfo = '';
While FieldName(Path) = 'RecoverableException' or FieldName(Path) =
   'DatabaseException' or
FieldName(Path) = 'ConversionException' or FieldName(Path) =
  'ParserException' or FieldName(Path) = 'UserException'
do
IF Length(Path.Label) > 0 THEN
SET Location = Path.Label;
End if;
IF Length(Path.Text) > 0 THEN
SET Diagnostics = Diagnostics || Path.Text || '. ';
End if;
MOVE Path Lastchild;
End while;
-- Construct the Specific Diagnostic Message.
MOVE Path Parent;
-- Determine the source of message which caused the error.
SET OutputRoot.XML.Error.Detail[Width].ExceptionType = FieldName(Path);
SET OutputRoot.XML.Error.Detail[Width].ErrorNumber = Path.Number;
SET OutputRoot.XML.Error.Detail[Width].SeverityLevel = Path.Severity;
SET OutputRoot.XML.Error.Detail[Width].ErrorSource = Location;
SET OutputRoot.XML.Error.Detail[Width].DiagnosticMessage= Diagnostics;
MOVE Path FirstChild;
-- while loop included to generalize coding to ensure future 
-- compatiblity in case of change in tree structure and to move 
-- the insert's Field.
While FieldName(Path) <> 'Insert' do
MOVE Path NextSibling;
End while;
-- while loop to traverse all the inserts and construct the 
-- additional diagnostic 
  message.
While LastMove(Path) do
IF Length(Path.Text) > 0 THEN
SET DiagnosticsInfo = DiagnosticsInfo || Path.Text || '. ';
End if;
MOVE Path NextSibling;
End while;
SET OutputRoot.XML.Error.Detail[Width].CauseOfError = DiagnosticsInfo;
SET OutputRoot.XML.Error.Detail[Width].MessageState = 
  cast(bitstream(InputBody) as CHAR ccsid 437);
SET Width = Width +1;
MOVE Path TO InputExceptionList.*[Width];
End while;
-- Else part to generate diagnostic message which has the structure 
-- of all the trees as 
  when the exception had occured 
else
SET I = 1;
While I < J do 
SET OutputRoot.XML.Error.*[I] = InputRoot.*[I]; SET I = I + 1; 
End while; 
SET OutputRoot.XML.Error.Environment = Environment; 
SET OutputRoot.XML.Error.LocalEnvironment = InputLocalEnvironment; 
SET OutputRoot.XML.Error.MessageState = 
  cast(bitstream(InputBody) as CHAR ccsid 437);
SET OutputRoot.XML.Error.ExceptionList = InputExceptionList;
End if;
SET OutputRoot.XML.Error.TimeStamp = 
  SUBSTRING(CAST(CURRENT_TIMESTAMP AS CHAR) FROM 12 FOR 23);
-- Flag set to Indicate Exception processing has occured in the flow.
SET Environment.Variables.ErrorFlag = 'Y';