How to output Salesforce session Id in Apex debug log?

You all know the method UserInfo.getSessionId() in Apex. You most probably have used it to make Webservice call. However, I find it difficult to output it so that I can use is externally.

If you would debug it, the debugger log will output:System.debug(UserInfo.getSessionId());
USER_DEBUG [1]|DEBUG|SESSION_ID_REMOVEDSystem.debug(‘——‘ + UserInfo.getSessionId() + ‘======’);
USER_DEBUG [1]|DEBUG|——SESSION_ID_REMOVED======

Even if you concatenate a string to it, you will always get the SESSION_ID_REMOVED.

However, after searching the internet, I found a solution which works:System.debug(UserInfo.getOrganizationId().substring(0, 15) + ‘ ‘ + UserInfo.getSessionId().substring(15));

Notice there is a space concatenating the organization id and the substring of the session Id. You need to remove it to make the Session Id valid.