You get that exception when your URL is wrong, or the Driver class is not registered wit hthe DriverManager. Double check your JDBC URL.
Also you are using Tomcat, which means web application classpath rules apply. If you are calling this code from a servlet your driver will nedd to be in WEB-INF/lib.
i have try mysql-connector-java-3.1.14 and mysql-connector-java-5.1.5 ,
Are you removing the older Jar file before trying the new? It could be your driver is being registered from the older jar and that uses a differernt JDBC url syntax. Java will normally just use the first version of a class it finds on the classpath.