Topic naming
Consider the following restrictions when deciding on your topic paths.
Restricted characters
Topics are identified by a path. A path is made up of path segments separated by the slash character (/).
Each path segment can be made up of one or more Unicode characters but must not contain any of the restricted characters mentioned below. The slash character (/) is not permitted in any path segment.
Reserved spaces
Paths starting with the path segment Diffusion are reserved for internal use.
Recommendations
Although all Unicode characters except the slash character (/) are supported, we recommend avoiding common regular expression metacharacters such as '*' and '?' in path names to avoid having to quote these characters in topic selector expressions.
Publisher API restricted characters
The Publisher API is used to create Java™ publishers that are hosted in the Diffusion™ server. This API has a wider set of restrictions on characters in topic paths.
In addition to the slash character (/), which is restricted in all path segments, the following characters are not permitted in paths to topics that are created by or selected by any publishers:
| Character | Reason for restriction |
|---|---|
| []\^$.|?*+() | These are all metacharacters used in regular expressions. Any path String that contains any of these characters is assumed to be a topic selector. These characters cannot be used in path segments. |
| Control/Reserved | No characters with a hexadecimal value of less than 0x2D. This includes some punctuation characters such as comma (,). |
| Whitespace | No characters defined as whitespace in Java (as indicated by the isWhiteSpace method of the Java Character class). |
This page last modified: 2018/11/09