资源描述:
《基于JSP的在线销售系统的设计与开发》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、附录(2)外文文献及翻译AnOverviewofServletandJSPTechnologyServletprogramrunningintheserver-side,dynamicallygeneratedWebpagewiththetraditionalCGIandmanyothersimilarcomparedtoCGItechnology,JavaServletwithamoreefficient,easiertouse,morepowerfulandhasbetterportability
2、,moresavingstoinvest.Keywords:JSPTechnology,Servlet,HTTPserver.1.1AServlet'sJobServletsareJavaprogramsthatrunonWeborapplicationservers,actingasamiddlelayerbetweenrequestscomingfromWebbrowsersorotherHTTPclientsanddatabasesorapplicationsontheHTTPserver.Th
3、eirjobistoperformthefollowingtasks,Readtheexplicitdatasentbytheclient.TheendusernormallyentersthisdatainanHTMLformonaWebpage.However,thedatacouldalsocomefromanappletoracustomHTTPclientprogram.1.ReadtheimplicitHTTPrequestdatasentbythebrowser.arrowgoingfr
4、omtheWebserver(thelayerwhereservletsandJSPexecute),buttherearereallytwovarietiesofdata:theexplicitdatathattheenduserentersinaformandthebehind-the-scenesHTTPinformation.Bothvarietiesarecritical.TheHTTPinformationincludescookies,informationaboutmediatypes
5、andcompressionschemesthebrowserunderstands,andsoon.2.Generatetheresults.Thisprocessmayrequiretalkingtoadatabase,executinganRMIorEJBcall,invokingaWebservice,orcomputingtheresponsedirectly.Yourrealdatamaybeinarelationaldatabase.Fine.Butyourdatabaseprobabl
6、ydoesn'tspeakHTTPorreturnresultsinHTML,sotheWebbrowsercan'ttalkdirectlytothedatabase.Evenifitcould,forsecurityreasons,youprobablywouldnotwantitto.Thesameargumentappliestomostotherapplications.YouneedtheWebmiddlelayertoextracttheresultsinsideadocument.3.
7、Sendtheexplicitdata(i.e.,thedocument)totheclient.8Thisdocumentcanbesentinavarietyofformats,includingtext(HTMLorXML),binary(GIFimages),orevenacompressedformatlikegzipthatislayeredontopofsomeotherunderlyingformat.But,HTMLisbyfarthemostcommonformat,soanimp
8、ortantservlet/JSPtaskistowraptheresultsinsideofHTML.4.SendtheimplicitHTTPresponsedata.Figure1-1showsasinglearrowgoingfromtheWebmiddlelayer(theservletorJSPpage)totheclient.But,therearereallytwovarietiesofdatasent:thedocumentitself