Lecture 17
18
Shell interpret method (60)
•Create a StringTokenizer for the input line, after throwing away Juno comments (# …)
•First token is the commandName (66)
•If it’s “logout”, then done (return false)
•Replace if else if … with dispatch table
–(70,71) look up commandObject in command table   (commandName String is key)
–(76) send commandObject a doIt() message 
•Polymorphism!