exception when deployed on tomcat - Please help

I built an application where I write 1 million row of data to the csv file. It works great when I deploy the application on dev mode(jetty server) but when I deployed the same application on tomcat I get the below exception.Please Can anyone suggest what could be the reason?

Exception in thread "http-bio-8080-exec-5" java.lang.OutOfMemoryError: Java heap space

at sun.util.resources.TimeZoneNames.getContents(TimeZoneNames.java:201)

at sun.util.resources.OpenListResourceBundle.loadLookup(OpenListResourceBundle.java:125)

at sun.util.resources.OpenListResourceBundle.loadLookupTablesIfNecessary(OpenListResourceBundle.java:113)

Exception in thread "http-bio-8080-AsyncTimeout" java.lang.OutOfMemoryError: Java heap space

org.apache.catalina.connector.CoyoteOutputStream@18174a0

at java.util.concurrent.ConcurrentLinkedQueue.iterator(ConcurrentLinkedQueue.java:667)

at org.apache.tomcat.util.net.JIoEndpoint$AsyncTimeout.run(JIoEndpoint.java:153)

at java.lang.Thread.run(Thread.java:722)

--
You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group.
To unsubscribe from this group and stop receiving emails from it, send an email to google-web-toolkit+unsubscribe@googlegroups.com.
To post to this group, send email to google-web-toolkit@googlegroups.com.
Visit this group at http://groups.google.com/group/google-web-toolkit.
For more options, visit https://groups.google.com/groups/opt_out.