计划中的错误和与他们战斗

I am relatively new to programming and especially to Java... So it takes me quite a long time to look for small snags - for example today I spent 5 hours to find that I wrote "servlet-name" as "sevlet-name" in DD and later on 2 more hours because I did not know that ServletExtractListener subclass should be public - Tomcat did not want to start. I am relatively new to programming and especial