JSTL的全称:JSP Standard Tag Library, jsp 标准标签库 JSTL的作用 提供给Java web开发人员一个标准通过的标签函数库和EL来取代传统直接在页面上嵌入java程序(Scription)的做法,以提高程序可读性,维护性和方便性 JSTL快速入门做法: 导入相应的jar包。 新建jsp的文件,引入标签库 < body > < h4 > 使用jstl的set if 判断输出内容 </ h4 > < c:set var = "i" value = "10" scope = "request" ></ c:set > < c:if test = " ${i eq 10} " > i=10 </ c:if > < c:set var = "age" value = "110" scope = "request" ></ c:set > ${ age } < c:remove var = "age" scope = "request" ></ c:remove > ${ age } < h4 > 使用out输出内容 </ h4 > < c:out value = "Hello" ></ c:out > < h4 > 使用out输出请求的参数,当参数为空时:可以设置默认值 </ h4 > < c:out value = " ${name} " default = "北京" ></ c:out > <% user usermsg= new user(); usermsg.setName( "admin" ); usermsg.setPassword( "123456" ); request.setAttribute( "usermsg" , usermsg); %> < c:set target = " ${ usermsg } " property = "name" value = "小凤" ></ c:set > ${ usermsg.name } < H3 > try catch 在标签中的使用 </ H3 > < h4 > 传统的方式 </ h4 > <% try { int i=10/0; } catch (Exception e){ e.printStackTrace(); } %> < h4 > 使用jstl的方式的异常 </ h4 > < c:catch var = "e" > <% int i=10/0; %> </ c:catch > ${ e.message } < h3 > 使用if进行判断操作 </ h3 > < c:set var = "tem" value = "6" scope = "page" ></ c:set > < c:if test = " ${ tem ge 10 } " var = "x" scope = "page" > tem>10 </ c:if > < c:if test = " ${ tem lt 10 } " var = "x" scope = "page" > tem < 10 </ c:if > ${ x } < h3 > c chose的jstl标签 </ h3 > < c:set var = "tem_choose" value = "16" scope = "page" ></ c:set > < c:choose > < c:when test = " ${ tem_choose lt 10 } " > tem_choose < 10 </ c:when > < c:when test = " ${ tem_choose ge 10 } " > tem_choose>=10 </ c:when > < c:otherwise > 其他 </ c:otherwise > </ c:choose > < h3 > 遍历数组 < h3 > <% String [] arrs={ "美美" , "小凤" , "小苍" , "冰冰" }; request.setAttribute( "arrs" ,arrs); %> < c:forEach var = "s" items = " ${ arrs } " > ${ s } </ c:forEach > < h3 > 遍历List < String > 集合 < h3 > <% List<String> list= new ArrayList<String>(); list.add( "AAA" ); list.add( "BBB" ); list.add( "CCC" ); request.setAttribute( "list" , list); %> < c:forEach var = "ls" items = " ${ list } " > ${ ls } </ c:forEach > < h3 > 遍历Map集合 < h3 > <% Map<String,String> map= new HashMap<String,String>(); map.put( "aa" , "我我我" ); map.put( "bb" , "你你你" ); map.put( "cc" , "她她她" ); request.setAttribute( "map" ,map); %> < c:forEach var = "ms" items = " ${ map } " > ${ ms.key } ---- ${ ms.value } </ c:forEach > </ body >
转载于:https://www.cnblogs.com/haofaner/p/5633395.html