Session: How to Defer Operations
Operations can be deferred till saveChanges
is called by using defer
method in advanced
session operations. All of the operations will update session state appropriately after saveChanges
is called.
Types of commands that can be deferred:
- PutCommandData
- DeleteCommandData
- DeletePrefixedCommandData
- PatchCommandData
- PutAttachmentCommandData
- DeleteAttachmentCommandData
- CopyAttachmentCommandData
- MoveAttachmentCommandData
- CountersBatchCommandData
Syntax
void defer(ICommandData command, ICommandData... commands);
void defer(ICommandData[] commands);
Parameters | ||
---|---|---|
ICommandData |
Command to be executed. | |
ICommandData[] |
Array of commands implementing ICommandData interface. |
Example
Map<String, Object> value1 = new HashMap<>();
value1.put("Name", "My Product");
value1.put("Supplier", "suppliers/999-A");
value1.put("@metadata", Collections.singletonMap("@collection", "Users"));
PutCommandDataWithJson putCommand1 =
new PutCommandDataWithJson("products/999-A",
null,
store.getConventions().getEntityMapper().valueToTree(value1));
HashMap<String, Object> value2 = new HashMap<>();
value2.put("Name", "My Product");
value2.put("Supplier", "suppliers/999-A");
value2.put("@metadata", Collections.singletonMap("@collection", "Suppliers"));
PutCommandDataWithJson putCommand2 =
new PutCommandDataWithJson("suppliers/999-A",
null,
store.getConventions().getEntityMapper().valueToTree(value2));
DeleteCommandData command3 = new DeleteCommandData("products/1-A", null);
session.advanced().defer(putCommand1, putCommand2, command3);