Unable use any values that contains a slash as a parameter in REST API

Summary

REST API will not work when the parameter contains slash "/".
For example, GET membership REST API URI will not work if the group contains slash "/".

Steps to Reproduce

1. Create a group that contains slash, for example "group/1"
2. Try to list out its members using REST API.

Actual Result:

1. <confluence base_URL>/rest/api/group/group/1/member ---> Gives 400 error.
2. <confluence base_URL>/rest/api/group/group%2F1/member ---> Gives 400 error.
3. <confluence base_URL>/rest/api/group/group%252F1/member ---> Gives 0 members

Notes

The issue happens because Tomcat actually intentionally prevents URL decoding of / for some kind of security reason:

• https://tomcat.apache.org/tomcat-8.0-doc/config/systemprops.html#Security

Workaround

Add the following in the JVM argument:

-Dorg.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH=true

More information on setting up JVM Arguments: Configuring System Properties