[LOG4J2-2943] Exception in Log4j2CloudConfigLoggingSystem

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.13.3
• Component/s: Spring

Environment

This code was called in dockerized springboot application so environment recreating is not easy, but error seems to be pretty obvious.

• Assignee: Unassigned
• Reporter: Rafał Figas
• Created: 12/Oct/20 17:01
• Updated: 12/Oct/20 18:48

Description

Exception is thrown at line 92 of class Log4j2CloudConfigLoggingSystem.

Reason is pretty simple:

        String location = props.getStringProperty(ConfigurationFactory.CONFIGURATION_FILE_PROPERTY);
        if (location != null) {
            List<String> list = Arrays.asList(super.getStandardConfigLocations());
            list.add(location);
            locations = list.toArray(new String[0]);
        }

Method Arrays.asList() returns fixed size list, so the next line call list.add(location); causes exception:

java.lang.UnsupportedOperationException: null
at java.util.AbstractList.add(AbstractList.java:148) ~[?:1.8.0_265]
at java.util.AbstractList.add(AbstractList.java:108) ~[?:1.8.0_265]
at org.apache.logging.log4j.spring.cloud.config.client.Log4j2CloudConfigLoggingSystem.getStandardConfigLocations(Log4j2CloudConfigLoggingSystem.java:92) ~[log4j-spring-cloud-config-client-2.13.3.jar:2.13.3]