Currently we force users to escape special characters (e. g. backslashes) in JMX item keys parameters:

https://www.zabbix.com/documentation/4.0/manual/config/items/itemtypes/jmx_monitoring#other_issues

This could be done by Zabbix automatically the same way it works with other item types, not forcing user to think about escaping at all.

In addition, number of escape characters in key parameters and error message can be different (2nd parameter, attributeName "invalid\attributeName" in example below) , which is confusing:

MBean objectName: com.example:Type=Hello
attribute: invalid\attributeName

item key:
jmx[com.example:Type=Hello,"invalid\\attributeName"]

error message:
getAttribute failed: ModelMBeanAttributeInfo not found for invalid\attributeName

Note that the error message is not so user-friendly also. So, the expected result could be like the following (with error message fixed):

MBean objectName: com.example:Type=Hello
attribute: invalid\attributeName

item key:
jmx[com.example:Type=Hello,"invalid\attributeName"]

error message:
MBean "com.example:Type=Hello" does not have attribute "invalid\attributeName"

The idea came from ZBX-13294.