blob: 72bd8b9d9f602e709cc003c0f10feec23084783c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
//
// ============LICENSE_START=======================================================
// Copyright (C) 2016-2018 Ericsson. All rights reserved.
// ================================================================================
// This file is licensed under the CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL LICENSE
// Full license text at https://creativecommons.org/licenses/by/4.0/legalcode
//
// SPDX-License-Identifier: CC-BY-4.0
// ============LICENSE_END=========================================================
//
// @author Sven van der Meer (sven.van.der.meer@ericsson.com)
//
== Configure AVRO Schema Handler
The AVRO schema handler is added to the configuration as follows:
[source%nowrap,json]
----
"engineServiceParameters":{
"engineParameters":{
"contextParameters":{
"parameterClassName" : "org.onap.policy.apex.context.parameters.ContextParameters",
"schemaParameters":{
"Avro":{
"parameterClassName" :
"org.onap.policy.apex.plugins.context.schema.avro.AvroSchemaHelperParameters"
}
}
}
}
}
----
Using the AVRO schema handler has one limitation: AVRO only supports field names that represent valid Java class names.
This means only letters and the character `_` are supported.
Characters commonly used in field names, such as `.` and `-`, are not supported by AVRO.
for more information see link:https://avro.apache.org/docs/1.8.1/spec.html#names[Avro Spec: Names].
To work with this limitation, the APEX Avro plugin will parse a given AVRO definition and replace _all_ occurrences of `.` and `-` with a `_`.
This means that
- In a policy model, if the AVRO schema defined a field as `my-name` the policy logic should access it as `my_name`
- In a policy model, if the AVRO schema defined a field as `my.name` the policy logic should access it as `my_name`
- There should be no field names that convert to the same internal name
** For instance the simultaneous use of `my_name`, `my.name`, and `my-name` should be avoided
** If not avoided, the event processing might create unwanted side effects
- If field names use any other not-supported character, the AVRO plugin will reject it
** Since AVRO uses lazy initialization, this rejection might only become visible at runtime
|
