在eclipse來開發Google App程式是最方便也不過的事了，只是不才小弟剛開始使用eclipse作為IDE介面，實在有許多地方不知其所以然，至今遇到兩個麻煩的問題。 Q1：利用Google App Engine Plug-in建立的Web Application Project竟然在新增JSP檔的時候無法編譯為Servlet (註：JSP在第一次執行時IDE會編譯成Servlet，web server實際執行的是此Servlet程式，所以初次開啟JSP會比較慢)，在JSP檔案前會出現一個小叉叉，編譯時出現Your Web Application Project must be configured to use a JDK in order to use JSPs.的錯誤訊息。 Google針對這個問題有特別解釋。 My JSPs aren't working, and there's an error that says "Your Web Application Project must be configured to use a JDK in order to use JSPs." What happened? Both the local App Engine server and the deployment process need to run javac in order to compile your JSPs. If your project isn't set to use a JDK ("Java Development Kit", which includes javac), then the JSPs can't be compiled. Go to Preferences > Java > Installed JREs and make sure that you have a JDK installed -- if you don't, you can easily download one. Now right-click on your project and choose Properties > Java Build P