WebComponentDevelopmentyaoyu@mail.neu.edu.cn姚羽编写主要内容„Servlet„JSP„MVCNortheasternUniversityIntroduction东北大学姚羽YaoYuyaoyu@mail.neu.edu.cnWebApplicationsandWebSites2„AwebsiteisacollectionofstaticHTMLpages.„Awebapplicationisawebsitewithdynamicfunctionalityontheserver.CGIProgramsontheWebServer„WebapplicationsuseHTMLformsastheuserinterfacetocodethatisrunningontheserver:„NortheasternUniversityDataispassedfromtheHTMLformtotheserverusingtheCGI.„TheCGIdataissentintheHTTPrequeststream.东北大学姚羽YaoYuNortheasternUniversityyaoyu@mail.neu.edu.cn东北大学姚羽YaoYuExecutionofCGIPrograms4yaoyu@mail.neu.edu.cn5NortheasternUniversity东北大学姚羽YaoYuyaoyu@mail.neu.edu.cn61ExecutionofCGIProgramsNortheasternUniversity东北大学姚羽AdvantagesandDisadvantagesYaoYuofCGIProgramsyaoyu@mail.neu.edu.cn„CGIprogramadvantages:„Writteninavarietyoflanguages„„RelativelyeasyforawebdesignertoreferenceCGIprogramdisadvantages:„JavaServlets7Eachshellisheavyweight„Notscalable„„NoCGIrtprocessingheastcodeern(businessUnilogic)versismingledityAservletisaJavatechnologywithHTML(presentationlogic)componentthatexecutesontheserver.„Languageisnotalwayssecureorobject-oriented„Servletsperformtaskssimilartothose„LanguageisnotalwaysplatformindependentperformedbyCGIprograms,butservletsexecuteinadifferent东北大学姚羽environment.YaoYu„ServletsNorthperformeastethernfollowing:Universityyaoyu@mail.neu.edu.cn„ProcesstheHTTPrequest„GeneratetheHTTPresponsedynamically东北大学姚羽YaoYuServletsontheWebServer8yaoyu@mail.neu.edu.cnExecutionofJavaServlets9NortheasternUniversity东北大学姚羽YaoYuNortheasternUniversityyaoyu@mail.neu.edu.cn东北大学姚羽YaoYuExecutionofJavaServlets10yaoyu@mail.neu.edu.cn11NortheasternUniversity东北大学姚羽YaoYuyaoyu@mail.neu.edu.cn122AdvantagesandDisadvantagesofJavaServlets„Javaservletadvantages:„Performance(threadsarefasterthanprocesses)„Scalable„TheJavaprogramminglanguageisrobustandobject-oriented„TheJavaprogramminglanguageisplatform„J