JavaWeb学习记录（十九）——jsp标签库

1.out标签

<%
//局部变量
String name="zsf>&<zz";
pageContext.setAttribute("names", name);
%>

1.<%=name %>
<br/>
2.${names }
<br/>
3. <c:out value="zsf<&>zz"></c:out>
<br/>
4. <c:out value="${names }" escapeXml="true"></c:out>
<br/>
5. <c:out value="${names }" escapeXml="false"></c:out>
<br/>
6.>&<

2.set标签

<h1>c:set标签</h1>
<div>
<!-- 第一种写法 -->
<c:set value="zsf" var="name" scope="request"/>
<!-- 第二种写法 -->
<c:set var="name">zsfs</c:set>
</div>
<div>
1.${requestScope.name }
<br/>
2.${name }
<br/>
3. <c:out value="${requestScope.name }"></c:out>
</div>

<div>
<!-- 关于对象的操作 -->
<jsp:useBean id="u" class="web14.domain.User" scope="page"/>

<jsp:setProperty property="name" name="u" value="zsf"/>
<jsp:getProperty property="name" name="u"/>
<br/>
<!-- target指向的是一个对象page域中 ${u}获取值 -->
<c:set target="${u }" property="name" value="zz"/>
<c:set target="${u }" property="name">aa</c:set>
<br/>

4.<c:out value="${u.name }"></c:out>
<br/>
5.${u.name }
</div>
</div>

3.remove

　<%
pageContext.setAttribute("name", "zsf");
%>
<br/>
1.${name }
<c:remove var="name" scope="page"/>
<br/>
2.${name }
<br/>

4.if

<c:if test="${1<2 }" var="u" scope="page">
<h1>1<2</h1>
</c:if>
<br/>${u }

5.catch

<c:catch var="e">
<%
int i=1/0;
%>
</c:catch>

1.${e }
<br/>
2.${e.message }

6.choose

<c:choose>
<c:when test="${1>2 }">
<h1>1大于2</h1>
</c:when>
<c:otherwise>
<h1>1不大于2</h1>
</c:otherwise>
</c:choose>

7.foreach

<!-- 1. -->
<c:forEach var="i" begin="1" end="8">
${i }
</c:forEach>
<br/>

<!-- 2. -->
<c:forEach var="i" begin="1" end="3" varStatus="v">
1.${v }<br/>
2.${v.first }<br/>
3.${v.last }<br/>
4.${v.count }<br/>
</c:forEach>
<br/>

<!-- 3. -->
<c:forEach var="i" begin="1" end="8" step="2">
${i }
</c:forEach>
<br/>

<!-- 4. -->
<c:forEach var="i" begin="3" end="8" varStatus="v">
<c:choose>
<c:when test="${v.count%2==0 }">
<h1 style="">${i }</h1>
</c:when>
<c:otherwise>
<h1 style="">${i }</h1>
</c:otherwise>
</c:choose>
</c:forEach>
<br/>

<%
Map<String,User> map=new HashMap<String ,User>();
map.put("001", new User("zsf1",null,null,0,0));
map.put("002", new User("zsf2",null,null,0,0));
map.put("003", new User("zsf3",null,null,0,0));
pageContext.setAttribute("map", map);
%>
<!-- 5. -->
<c:forEach var="v" items="${map }">
${v.key }<br/>
</c:forEach>
<c:forEach var="v" items="${map }">
${v.value.name }<br/>
</c:forEach>

<%
Set<User> set=new HashSet<User>();
set.add( new User("zsf11",null,null,0,0));
set.add( new User("zsf22",null,null,0,0));
set.add( new User("zsf33",null,null,0,0));
pageContext.setAttribute("set", set);
%>

<!-- 6. -->
<c:forEach var="v" items="${set }">
${v.name }<br/>
</c:forEach>

<c:forEach var="i" items="<%=new int[]{2,4} %>">
${i }
</c:forEach>

8.forTokens

<c:forTokens items="a:b:c:d" delims=":" var="token">
<c:out value="${token }"/><br/>
</c:forTokens>