This section provides notes on developing CORBA server applications.
The table below lists CORBA data types and their corresponding data types in other languages.
For details on data types that can be defined, refer to the "Interstage Studio User's Guide".
CORBA type | COBOL (object-oriented COBOL) mapping type | COBOL native type |
|---|---|---|
long | CORBA-long | PIC S9(9) COMP-5 |
unsigned long | CORBA-unsigned-long | PIC 9(9) COMP-5 |
short | CORBA-short | PIC S9(4) COMP-5 |
unsigned short | CORBA-unsigned-short | PIC 9(4) COMP-5 |
long long | CORBA-long-long | PIC S9(18) COMP-5 |
unsigned long long | CORBA-unsigned-long-long | PIC 9(18) COMP-5 |
float | CORBA-float | COMP-1 |
double | CORBA-double | COMP-2 |
char | CORBA-char | PIC X |
wchar | CORBA-wchar | PIC N |
octet | CORBA-octet | PIC X |
boolean | CORBA-boolean | PIC 1(1) |
fixed <m+n,n> | Cannot be used | PIC S9 (m+n,n) PACKED-DECIMAL |
string (fixed length) | PIC X(n) | PIC X(n) |
string (variable length) | Cannot be used | Cannot be used |
wstring (fixed length) | PIC N(n) | PIC N(n) |
wstring (variable length) | Cannot be used | Cannot be used |
enum | CORBA-enum | PIC 9(10) COMP-5 |
any | Cannot be used | Cannot be used |
Structure (fixed length) | Group item | Group item |
Structure (variable length) | Class | Class |
Union | Class | Class |
sequence type (fixed length) | Class | Class |
sequence type (variable length) | Class | Class |
array type | Cannot be used | Cannot be used |
The CORBA server application generation wizard does not support the data types listed below. To use these data types, create templates and modify the relevant IDL file and program source according to the "Interstage Application Server Distributed Application Development Guide (CORBA Service Edition)".
octet
string (variable length)
wstring (variable length)
enum
Structure (variable length)
Union
sequence type (variable length)
Iteration items are mapped to the sequence type as described below.
Number of dimensions | Object-oriented COBOL |
|---|---|
1 | sequence type (fixed length) |
2 to 5 | Cannot be used |
Mapping a iteration definition to the IDL file
Mapping of an iteration definition to the IDL file is explained below.
One-dimensional items are mapped to the sequence type.
The following example shows mapping with a 4-byte integer specified for the data type, "a" for the type name, and 10 for the iteration count.
typedef sequence<long, 10> a ;
Operation of iteration items
Operation of iteration items is explained below.
Operation of iteration items is shown below. When the following IDL file is compiled, the sequence type is mapped to a sequence class.
IDL file
module ODsample {
typedef sequence<long,10> sampleseq;
interface seqtest {
sampleseq op1(in sampleseq param1,
out sampleseq param2,
inout sampleseq param3);
};
};The factory method, object methods, and properties of the sequence class are listed below.
Category | Method/property name | Function |
|---|---|---|
Factory method | NEW-WITH-LENGTH | Creates a sequence class of the specified length |
Object method | GET-VALUE | Obtains the value of the element of the specified number |
SET-VALUE | Sets a value for the element of the specified number | |
CLONE | Makes a copy of a sequence class | |
Property | SEQ-MAXIMUM | Gets the value of the maximum sequence length |
SEQ-LENGTH | Gets or sets the sequence length value |
Example of using iteration items
METHOD-ID. OP1 AS "OP1" OVERRIDE.
* <IDL-INFO-START>
* sampleseq op1(in sampleseq param1,out sampleseq param2,inout sampleseq param3)
* <IDL-INFO-END>
DATA DIVISION.
WORKING-STORAGE SECTION.
01 SEQ-VALUE TYPE CORBA-LONG.
01 I TYPE CORBA-UNSIGNED-LONG.
LINKAGE SECTION.
01 RETURN-VALUE TYPE ODSAMPLE-SAMPLESEQ.
01 PARAM1 TYPE ODSAMPLE-SAMPLESEQ.
01 PARAM2 TYPE ODSAMPLE-SAMPLESEQ.
01 PARAM3 TYPE ODSAMPLE-SAMPLESEQ.
PROCEDURE DIVISION
USING
PARAM1
PARAM2
PARAM3
RETURNING RETURN-VALUE
.
* IN PARAMETER
PERFORM VARYING I FROM 1 BY 1 UNTIL I > 10
INVOKE PARAM1 "GET-VALUE" USING I RETURNING SEQ-VALUE
END-PERFORM.
* OUT PARAMETER
INVOKE SEQUENCE-LONG-10 "NEW" RETURNING PARAM2.
MOVE 10 TO SEQ-LENGTH OF PARAM2.
PERFORM VARYING I FROM 1 BY 1 UNTIL I > 10
COMPUTE SEQ-VALUE = I * 100
INVOKE PARAM2 "SET-VALUE" USING I SEQ-VALUE
END-PERFORM.
* INOUT PARAMETER
PERFORM VARYING I FROM 1 BY 1 UNTIL I > 10
INVOKE PARAM3 "GET-VALUE" USING I RETURNING SEQ-VALUE
COMPUTE SEQ-VALUE = SEQ-VALUE * 100
INVOKE PARAM3 "SET-VALUE" USING I SEQ-VALUE
END-PERFORM.
* RESULT
INVOKE SEQUENCE-LONG-10 "NEW" RETURNING RETURN-VALUE.
MOVE 10 TO SEQ-LENGTH OF RETURN-VALUE.
PERFORM VARYING I FROM 1 BY 1 UNTIL I > 10
COMPUTE SEQ-VALUE = I * 10000
INVOKE RETURN-VALUE "SET-VALUE" USING I SEQ-VALUE
END-PERFORM.
END METHOD OP1.Point
As for the sequence type, in cases where the mode is "in" or "inout", a data area already exists on the calling side and need not be allocated. However, in cases of "out" mode or the return value, the server application must allocate a data area.
Structures are mapped to group items as described below.
Type | Object-oriented COBOL |
|---|---|
Structure (fixed length) | Group item |
Structure (variable length) | Cannot be used |
An example of using structures when the following IDL file is compiled, is shown below.
module ODsample {
struct samplestruct {
long item1;
long item2;
};
interface structtest {
samplestruct op1(in samplestruct param1,
out samplestruct param2,
inout samplestruct param3);
};
}; METHOD-ID. OP1 AS "OP1" OVERRIDE.
* <IDL-INFO-START>
* samplestruct op1(in samplestruct param1,out samplestruct param2,inout samplestruct param3)
* <IDL-INFO-END>
DATA DIVISION.
WORKING-STORAGE SECTION.
LINKAGE SECTION.
01 RETURN-VALUE TYPE ODSAMPLE-SAMPLESTRUCT.
01 PARAM1 TYPE ODSAMPLE-SAMPLESTRUCT.
01 PARAM2 TYPE ODSAMPLE-SAMPLESTRUCT.
01 PARAM3 TYPE ODSAMPLE-SAMPLESTRUCT.
PROCEDURE DIVISION
USING
PARAM1
PARAM2
PARAM3
RETURNING RETURN-VALUE
.
* IN PARAMETER
* OUT PARAMETER
* INOUT PARAMETER
MOVE ITEM1 OF PARAM1 TO ITEM1 OF PARAM2.
MOVE ITEM2 OF PARAM3 TO ITEM2 OF PARAM2.
MOVE 2 TO ITEM1 OF PARAM3.
MOVE 3 TO ITEM2 OF PARAM3.
* RESULT
MOVE 4 TO ITEM1 OF RETURN-VALUE.
MOVE 5 TO ITEM2 OF RETURN-VALUE.
END METHOD OP1.The IDL generator can generate neither inheritance code nor #include statements.
To inherit a module or interface, edit the IDL file, using an editor to add coding of the inherited part.
For a program to be operated on multi-instance system, it is mandatory that the ORB initialization part of the program is modified.
For details about the multi-instance system and ORB initialization method, refer to the "Interstage Application Server Distributed Application Development Guide (CORBA Service Edition)" and "Interstage Application Server Reference Manual (Command Edition)".
Following are two methods for creating the CORBA server application that performs database access .
Create the class library for accessing the database in advance, and create the CORBA server application that uses this class. Class library can be used as a component in other applications.
Describe the instructions that access the database directly in the business method of the CORBA server application.
For details and notes about the database access method (ESQL/COBOL etc.) provided by NetCOBOL, refer to "NetCOBOL Users' Guide" and "NetCOBOL Software Instructions".