3.0 KiB
3.0 KiB
1. Goal
A mobile crane hire company checks a lift plan before it dispatches a crane. The dispatch office calls one check class for each lift plan. If the check fails, the check class raises a class-based exception. The exception carries a message from a new message class.
Create the message class, the exception class, and the check class.
2. Open questions
None.
3. Context
- All objects are in package $TMP.
- The dispatch office already exists. It calls the check class and shows the message text of the exception.
- No message class for lift plans exists yet.
4. Contract
Message class {{P}}MSG_CRANE
Messages 001, 002, 003, 004 and 005 must exist. The Business rules give the number, the type and the exact text of each message.
Exception class {{P}}CX_CRANE_ERROR
- Public and final. It inherits from CX_STATIC_CHECK.
- Public constructor with these parameters:
- iv_msgno, TYPE symsgno
- iv_attr1, TYPE string, optional
- iv_attr2, TYPE string, optional
- Public method get_message_text, returning VALUE rv_text TYPE string. The method returns the text of the message that the constructor received, with &1 replaced by iv_attr1 and &2 replaced by iv_attr2.
Check class {{P}}LIFT_CHECK
- Public and final.
- Public type ty_lift_plan with these components:
- plan_id, TYPE string
- crane_id, TYPE string
- load_kg, TYPE decfloat34
- capacity_kg, TYPE decfloat34
- wind_kmh, TYPE decfloat34
- Public method check_lift_plan with the importing parameter iv_plan of type ty_lift_plan. The method raises {{P}}CX_CRANE_ERROR.
5. Business rules
5.1 Messages of {{P}}MSG_CRANE
| Number | Type | Text |
|---|---|---|
| 001 | E | Lift plan &1 has no crane |
| 002 | E | Lift plan &1 is too heavy for crane &2 |
| 003 | E | Lift plan &1 is blocked because of wind |
| 004 | W | Lift plan &1 is near the load limit |
| 005 | I | Lift plan &1 is approved |
Messages 001, 002 and 003 are errors. Message 004 is a warning. Message 005 is an information message. The dispatch list shows messages 004 and 005.
5.2 Check of a lift plan
The method check_lift_plan checks the lift plan in this order:
- If crane_id is initial, raise {{P}}CX_CRANE_ERROR with message 001 and attribute 1 = plan_id.
- Else if load_kg is greater than capacity_kg, raise {{P}}CX_CRANE_ERROR with message 002, attribute 1 = plan_id, attribute 2 = crane_id.
- Else if wind_kmh is greater than 60, raise {{P}}CX_CRANE_ERROR with message 003 and attribute 1 = plan_id.
- Else the method ends without an exception.
6. Constraints
- Release target: ABAP Platform 2025 (SAP_BASIS 816).
- Clean ABAP. Keep every method below 40 statements.
- Out of scope: no database table, no CDS view, no report. Do not change other objects in package $TMP.
7. Acceptance
- All objects are active and have no syntax error.
- The hidden tests pass.
- Write ABAP Unit tests: a global test class for the message class and the exception class, and local test classes for {{P}}LIFT_CHECK.