This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
have you tried the way of tomcat restarting as it tomcat-manager does ? tomcat ships with ant task that does redeployment well. and invoking ant task from java code looks better than running sh manually. plus it will gives you crossplatfom-compatibility.