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CICS GETNEXT CONTAINER (CHANNEL) - Channel Container Browsing

CICS GETNEXT CONTAINER (CHANNEL) provides channel container browsing capabilities for programs and transactions. It enables programs to browse channel containers, iterate through container lists, and handle channel container browsing operations in CICS environments.

What is CICS GETNEXT CONTAINER (CHANNEL)?

CICS GETNEXT CONTAINER (CHANNEL) is a command that allows programs to browse channel containers in sequence, retrieve the next container in a browse operation, and iterate through channel container lists. It provides channel container browsing capabilities, container iteration, and channel container list handling for CICS applications.

Command Syntax

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EXEC CICS GETNEXT CONTAINER
    CHANNEL(channel-name)
    INTO(data-area)
    LENGTH(data-length)
    [RESP(response-code)]
END-EXEC

Parameters

Required Parameters

  • CHANNEL(channel-name) - Name of channel to browse
  • INTO(data-area) - Data area to receive container information
  • LENGTH(data-length) - Length of data area

Optional Parameters

  • RESP(response-code) - Response code variable

Channel Container Types

Data Containers

Containers with application data

  • • APPLICATION DATA - Browse application data containers
  • • BUSINESS DATA - Browse business data containers
  • • TRANSACTION DATA - Browse transaction data containers
  • • PROCESS DATA - Browse process data containers

Control Containers

Containers with control information

  • • CONTROL DATA - Browse control data containers
  • • STATUS DATA - Browse status data containers
  • • CONFIGURATION DATA - Browse configuration data containers
  • • METADATA - Browse metadata containers

Message Containers

Containers with message data

  • • MESSAGE DATA - Browse message data containers
  • • NOTIFICATION DATA - Browse notification data containers
  • • ALERT DATA - Browse alert data containers
  • • EVENT DATA - Browse event data containers

Custom Containers

User-defined containers

  • • CUSTOM DATA - Browse custom data containers
  • • USER DATA - Browse user data containers
  • • WORKFLOW DATA - Browse workflow data containers
  • • INTEGRATION DATA - Browse integration data containers

Programming Examples

Basic Channel Container Browsing

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. GETNEXTCONTAINERCHANNEL01.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  CHANNEL-NAME PIC X(8) VALUE 'MAINCHAN'.
       01  CONTAINER-DATA PIC X(100).
       01  DATA-LENGTH PIC S9(8) COMP VALUE 100.
       01  RESPONSE-CODE PIC S9(8) COMP.
       01  CONTAINER-COUNT PIC S9(4) COMP VALUE 0.
       01  MAX-CONTAINERS PIC S9(4) COMP VALUE 10.
       01  BROWSE-ACTIVE PIC X(1) VALUE 'Y'.
       
       PROCEDURE DIVISION.
           PERFORM START-CHANNEL-CONTAINER-BROWSE
           
           PERFORM UNTIL BROWSE-ACTIVE = 'N'
               OR CONTAINER-COUNT >= MAX-CONTAINERS
               
               EXEC CICS GETNEXT CONTAINER
                   CHANNEL(CHANNEL-NAME)
                   INTO(CONTAINER-DATA)
                   LENGTH(DATA-LENGTH)
                   RESP(RESPONSE-CODE)
               END-EXEC
               
               IF RESPONSE-CODE = DFHRESP(NORMAL)
                   ADD 1 TO CONTAINER-COUNT
                   DISPLAY 'Container ' CONTAINER-COUNT ': ' CONTAINER-DATA(1:DATA-LENGTH)
               ELSE
                   MOVE 'N' TO BROWSE-ACTIVE
                   DISPLAY 'End of containers or error occurred'
               END-IF
           END-PERFORM
           
           EXEC CICS ENDBROWSE CONTAINER END-EXEC
           EXEC CICS RETURN END-EXEC.

Advanced Channel Container Management

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. GETNEXTCONTAINERCHANNEL02.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  CHANNEL-NAME PIC X(8) VALUE 'MAINCHAN'.
       01  CONTAINER-DATA PIC X(200).
       01  DATA-LENGTH PIC S9(8) COMP VALUE 200.
       01  RESPONSE-CODE PIC S9(8) COMP.
       01  CONTAINER-COUNT PIC S9(4) COMP VALUE 0.
       01  MAX-CONTAINERS PIC S9(4) COMP VALUE 20.
       01  BROWSE-ACTIVE PIC X(1) VALUE 'Y'.
       01  CONTAINER-LIST.
           05  CONTAINER-ITEM OCCURS 20 TIMES.
               10  CONTAINER-ID PIC X(8).
               10  CONTAINER-STATUS PIC X(1).
       
       PROCEDURE DIVISION.
           PERFORM START-CHANNEL-CONTAINER-BROWSE
           PERFORM BROWSE-CHANNEL-CONTAINERS
           PERFORM END-CHANNEL-CONTAINER-BROWSE
           
           EXEC CICS RETURN END-EXEC.
       
       START-CHANNEL-CONTAINER-BROWSE.
           EXEC CICS STARTBROWSE CONTAINER
               CHANNEL(CHANNEL-NAME)
           END-EXEC.
       
       BROWSE-CHANNEL-CONTAINERS.
           PERFORM UNTIL BROWSE-ACTIVE = 'N'
               OR CONTAINER-COUNT >= MAX-CONTAINERS
               
               EXEC CICS GETNEXT CONTAINER
                   CHANNEL(CHANNEL-NAME)
                   INTO(CONTAINER-DATA)
                   LENGTH(DATA-LENGTH)
                   RESP(RESPONSE-CODE)
               END-EXEC
               
               IF RESPONSE-CODE = DFHRESP(NORMAL)
                   ADD 1 TO CONTAINER-COUNT
                   MOVE CONTAINER-DATA(1:8) TO CONTAINER-ID(CONTAINER-COUNT)
                   MOVE 'A' TO CONTAINER-STATUS(CONTAINER-COUNT)
                   DISPLAY 'Retrieved container: ' CONTAINER-ID(CONTAINER-COUNT)
               ELSE
                   MOVE 'N' TO BROWSE-ACTIVE
                   DISPLAY 'End of containers or error occurred'
               END-IF
           END-PERFORM.
       
       END-CHANNEL-CONTAINER-BROWSE.
           EXEC CICS ENDBROWSE CONTAINER END-EXEC.

Error Handling with Channel Container Browsing

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. GETNEXTCONTAINERCHANNEL03.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  CHANNEL-NAME PIC X(8) VALUE 'TESTCHAN'.
       01  CONTAINER-DATA PIC X(100).
       01  DATA-LENGTH PIC S9(8) COMP VALUE 100.
       01  RESPONSE-CODE PIC S9(8) COMP.
       01  CONTAINER-COUNT PIC S9(4) COMP VALUE 0.
       01  MAX-CONTAINERS PIC S9(4) COMP VALUE 15.
       01  BROWSE-ACTIVE PIC X(1) VALUE 'Y'.
       01  RETRY-COUNT PIC S9(2) COMP VALUE 0.
       01  MAX-RETRIES PIC S9(2) COMP VALUE 3.
       
       PROCEDURE DIVISION.
           PERFORM START-CHANNEL-CONTAINER-BROWSE
           PERFORM BROWSE-CHANNEL-CONTAINERS-WITH-ERROR-HANDLING
           PERFORM END-CHANNEL-CONTAINER-BROWSE
           
           EXEC CICS RETURN END-EXEC.
       
       START-CHANNEL-CONTAINER-BROWSE.
           EXEC CICS STARTBROWSE CONTAINER
               CHANNEL(CHANNEL-NAME)
           END-EXEC.
       
       BROWSE-CHANNEL-CONTAINERS-WITH-ERROR-HANDLING.
           PERFORM UNTIL BROWSE-ACTIVE = 'N'
               OR CONTAINER-COUNT >= MAX-CONTAINERS
               
               PERFORM GET-NEXT-CHANNEL-CONTAINER
               
               IF RESPONSE-CODE = DFHRESP(NORMAL)
                   ADD 1 TO CONTAINER-COUNT
                   DISPLAY 'Container ' CONTAINER-COUNT ': ' CONTAINER-DATA(1:DATA-LENGTH)
               ELSE
                   PERFORM HANDLE-CHANNEL-BROWSE-ERROR
               END-IF
           END-PERFORM.
       
       GET-NEXT-CHANNEL-CONTAINER.
           EXEC CICS GETNEXT CONTAINER
               CHANNEL(CHANNEL-NAME)
               INTO(CONTAINER-DATA)
               LENGTH(DATA-LENGTH)
               RESP(RESPONSE-CODE)
           END-EXEC.
       
       HANDLE-CHANNEL-BROWSE-ERROR.
           EVALUATE RESPONSE-CODE
               WHEN DFHRESP(ENDFILE)
                   MOVE 'N' TO BROWSE-ACTIVE
                   DISPLAY 'End of containers reached'
               WHEN DFHRESP(NOTAUTH)
                   DISPLAY 'Not authorized to browse containers'
                   MOVE 'N' TO BROWSE-ACTIVE
               WHEN DFHRESP(INVREQ)
                   DISPLAY 'Invalid browse request'
                   MOVE 'N' TO BROWSE-ACTIVE
               WHEN DFHRESP(CONTAINERERR)
                   DISPLAY 'Container browse error'
                   MOVE 'N' TO BROWSE-ACTIVE
               WHEN OTHER
                   DISPLAY 'Unexpected error occurred'
                   MOVE 'N' TO BROWSE-ACTIVE
           END-EVALUATE.
       
       END-CHANNEL-CONTAINER-BROWSE.
           EXEC CICS ENDBROWSE CONTAINER END-EXEC.

Channel Container Management

Container Browsing

  • • Container Iteration - Iterate through containers
  • • Container Filtering - Filter container results
  • • Container Sorting - Sort container results
  • • Container Pagination - Paginate container results

Container Monitoring

  • • Container Tracking - Track container activities
  • • Container Logging - Log container operations
  • • Container Auditing - Audit container requests
  • • Container Reporting - Generate container reports

Container Lifecycle

  • • Container Creation - Create new channel containers
  • • Container Initialization - Initialize channel containers
  • • Container Processing - Process channel containers
  • • Container Cleanup - Clean up channel container resources

Error Recovery

  • • Error Detection - Detect channel container errors
  • • Error Recovery - Recover from channel container errors
  • • Retry Mechanisms - Implement retry logic
  • • Fallback Procedures - Use fallback procedures

Error Handling

Common Response Codes

  • DFHRESP(NORMAL) - Channel container retrieved successfully
  • DFHRESP(ENDFILE) - End of containers reached
  • DFHRESP(NOTAUTH) - Not authorized to browse containers
  • DFHRESP(INVREQ) - Invalid browse request
  • DFHRESP(CONTAINERERR) - Container browse error
  • DFHRESP(CONTAINERMANAGEMENTERR) - Container management error

Performance Considerations

Container Efficiency

  • • Optimize container operations - Use efficient container handling
  • • Minimize container overhead - Reduce container processing overhead
  • • Use container pooling - Implement container pooling
  • • Monitor container frequency - Track container access patterns

System Impact

  • • Monitor system impact - Track how containers affect the system
  • • Optimize container handling - Ensure efficient container processing
  • • Manage container usage - Monitor container consumption
  • • Track performance metrics - Monitor container handling performance

Best Practices

Channel Container Browsing Best Practices

  • • Always start and end browse operations properly
  • • Implement proper error handling for container operations
  • • Validate container requests before processing
  • • Use appropriate container browsing methods
  • • Monitor container browsing activities and performance
  • • Maintain container audit trails
  • • Handle container errors gracefully

Explain It Like I'm 5 Years Old

Think of CICS GETNEXT CONTAINER (CHANNEL) like looking through a toy box:

  • • Open Toy Box: "Open the toy box to start looking" - Start browse
  • • Look at Toy: "Look at the next toy" - Get next container
  • • Keep Looking: "Keep looking at toys one by one" - Continue browsing
  • • End of Toys: "You reach the end of the toy box" - End of containers
  • • Close Toy Box: "Close the toy box when done" - End browse

Exercises

Exercise 1: Basic Channel Container Browsing

Create a program that browses through channel containers using GETNEXT CONTAINER.

Exercise 2: Advanced Channel Container Management

Write a program that manages channel container browsing with filtering and sorting.

Exercise 3: Error Handling

Implement comprehensive error handling for channel container browsing failures.

Related Concepts

Channel Management

Managing system channels

Container Management

Managing channel containers

Container Browsing

Browsing container information

Container Operations

Channel container operations

Error Handling

Managing container errors