As said before, logs cannot be retrieved from the database by navigating the LoggingInstance to its logs. Instead, logs of a process instance should always be queried from the database. The LoggingSession has 2 methods that serve this purpose.

The first method retrieves all the logs for a process instance. These logs will be grouped by token in a Map. The map will associate a List of ProcessLogs with every Token in the process instance. The list will contain the ProcessLogs in the same ordered as they were created.

public class LoggingSession {
  ...
  public Map findLogsByProcessInstance(long processInstanceId) {...}
  ...
}

The second method retrieves the logs for a specific Token. The returned list will contain the ProcessLogs in the same ordered as they were created.

public class LoggingSession {
  public List findLogsByToken(long tokenId) {...}
  ...
}