Blog / 2010 / October / 6

Modify Java Thread Name

October 6, 2010

Part of my application generates a unique jobid for a given thread. I wanted to add that unique key to the thread name so that log4j debugging would show it, and we could work out which job the thread processed.

Here's the code I used to add the jobid to the thread:

String lExistingThreadName = Thread.currentThread().getName();

if (lExistingThreadName.indexOf("@#") > -1)
{
  lExistingThreadName = lExistingThreadName.substring(0, lExistingThreadName.indexOf("@#"));
}

StringBuffer lNewThreadName = new StringBuffer(lExistingThreadName);
lNewThreadName.append("@#");
lNewThreadName.append(lJobId);
Thread.currentThread().setName(lNewThreadName.toString());

This was then logged using %t in the following log4j config:

<appender name="A1" class="org.apache.log4j.DailyRollingFileAppender">
  <param name="File" value="logs/made-broker-lender-edl-pdi.log"/>
  <param name="Append" value="true"/>
  <layout class="org.apache.log4j.PatternLayout">
     <param name="ConversionPattern" value="%d{DATE} %-5p %t %C{2} - %m%n" />
  </layout>
</appender>

Tags: log4j thread name