互联网开发技术第七讲Web技术.pptxVIP

互联网开发技术

InternetSystemsDevelopmentTechnologies蔡剑,Ph.D.AssistantProfessorinManagementScienceandE-BusinessGuanghuaSchoolofManagementPekingUniversity

Web层技术(III)CustomTagsJSPandXML123654ProposalsdueinnextweekGrouppresentthereprojectsinnextweekJSTLAboutTheCourseProject:本讲内容

Review:UseJavaBeanswithJSPJSPWebContainerRequestResponseBrowserServerDatabaseJavaBeansJavaBeansJSPJSPhandlestheface.JavaBeanhandlesthelogicandcomplexity.

CustomJSPTagSimpleCustomTag: ics:tagname/AttributeCustomTag: ics:checkinputdatabasename=%=userBean.getDatabase()%/ Usetldfiletoconfigthetagattributes3.BodyCustomTag:ics:displayformat=smalltable%user.checkstatus();%table……strong ……tableics:logmessage=Tableprinted//ics:display

CustomJSPTag(Con’t)030201CustomTagcanbeusedinScript:ics:connectionid=icdbtype=DataSourcename=icworkdatabase/%icdb.getConnection();%

CustomTagDevelopment3241采用特定的API编写实现标签处理的程序位置/WEB-INF位置/WEB-INF/classesor/WEB-INF/lib建立一个taglibrarydescriptor(TLD)文件用来描述customtag

TagLibraryDescriptor?xmlversion=1.0encoding=ISO-8859-1?!DOCTYPEtaglibPUBLIC-//SunMicrosystems,Inc.//DTDJSPTagLibrary1.2//ENdtd/web－jsptaglibrary_1_2.dtdtaglibtlib-version1.0/tlib-versionjsp-version1.2/jsp-versionshort-nameics/short-nameuri/uridisplay-nameIcsampleTag/display-namedescriptionSampleTLDinJWADBook/description

TagLibraryDescriptor(Con’t)tagnamewordcount/nametag-class/tag-classbody-contentempty/body-contentattributenameinputname/namerequiredtrue/requiredrtexprvaluefalse/rtexprvalue/attributeattributenamewarnEmpty/namerequiredtrue/requiredrtexprvaluetrue/rtexprvaluetypeboolean/type/attribute/tag……/taglib

ASimpleTagpublicclassTimeTagimplementsTag{…publicintdoStartTag()throwsJspException{try{calendar=Calendar.getInstance();pageCo