Java/JSTL/Loop
Содержание
- 1 Count to 10 Example: tracking even and odd
- 2 Count to 10 Example using JSTL
- 3 JSTL: another for each and status
- 4 JSTL: Conditional Support -- Simple Conditional Execution Example
- 5 JSTL For Each
- 6 JSTL: for each and status
- 7 JSTL: for each loop
- 8 JSTL Form Value and ForEach Loop
- 9 JSTL: fortokens
- 10 JSTL Tag collaboration with a fixed loop
Count to 10 Example: tracking even and odd
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.ru/jstl/core-rt" prefix="c-rt" %>
<html>
<head>
<title>Count to 10 Example(tracking even and odd)</title>
</head>
<body>
<table border="0">
<c:forEach var="i" begin="1" end="10" varStatus="status">
<jsp:useBean id="status"
type="javax.servlet.jsp.jstl.core.LoopTagStatus" />
<c-rt:choose>
<c-rt:when test="<%=status.getCount()%2==0%>">
<c:set var="color" value="#eeeeee" />
</c-rt:when>
<c-rt:otherwise>
<c:set var="color" value="#dddddd" />
</c-rt:otherwise>
</c-rt:choose>
<tr>
<td width="200" bgcolor="<c:out value="${color}"/>">
<c:out value="${i}" />
</td>
</tr>
</c:forEach>
</table>
</body>
</html>
Count to 10 Example using JSTL
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<html>
<head>
<title>Count to 10 Example(using JSTL)</title>
</head>
<body>
<table border="1">
<tr>
<td valign="top">
<h3>From 1 to 10</h3>
<c:forEach var="i" begin="1" end="10">
<c:out value="${i}" />
<br />
</c:forEach>
</td>
<td valign="top">
<h3>From 10 to 1</h3>
<c:forEach var="i" begin="1" end="10">
<c:out value="${11-i}" />
<br />
</c:forEach>
</td>
</tr>
<tr>
<td>
<h3>By Twos</h3>
<c:forEach var="i" begin="2" end="10" step="2">
<c:out value="${i}" />
<br />
</c:forEach>
</td>
<td valign="top">
</td>
</tr>
</table>
</body>
</html>
JSTL: another for each and status
<%@ taglib prefix="c" uri="http://java.sun.ru/jstl/core" %>
<%
synchronized (pageContext) {
String[] names = {"Joe", "Rosy", "Petter", "Rob"};
pageContext.setAttribute("names", names, PageContext.PAGE_SCOPE);
}
%>
<html>
<head>
<title>forEach and status</title>
</head>
<body>
The forEach tag exposes a scoped variable called "count", which
is the position of the current element within the collection. <br />
<c:forEach var="currentName" items="${pageScope.names}" varStatus="status">
Family member #<c:out value="${status.count}" /> is
<c:out value="${currentName}" /> <br />
</c:forEach>
</body>
</html>
JSTL: Conditional Support -- Simple Conditional Execution Example
<%@ taglib prefix="c" uri="http://java.sun.ru/jstl/core" %>
<html>
<head>
<title>JSTL: Conditional Support -- Simple Conditional Execution Example</title>
</head>
<body bgcolor="#FFFFFF">
<h3>Loop in JSTL</h3>
<c:forEach var="i" begin="1" end="10" step="1">
<c:out value="${i}" />
<br />
</c:forEach>
</body>
</html>
JSTL For Each
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %><%@ taglib uri="http://java.sun.ru/jstl/xml" prefix="x" %>
<html>
<head>
<title>Reading RSS</title>
</head>
<body>
<c:import var="news"
url="http://www.wired.ru/news_drop/netcenter/netcenter.rdf" />
<x:parse var="doc" xml="${news}" />
<table border="1" width="100%">
<tr bgcolor="blue">
<td align="center">
<font color="white" size="+2">
<b>
<x:out select="$doc/rss/channel/title" />
</b>
</font>
<br />
<font color="white" size="-2">
<x:out select="$doc/rss/channel/pubDate" />
</font>
</td>
</tr>
<tr>
<td valign="top">
<x:out select="$doc/rss/channel/description" />
</td>
</tr>
<x:forEach var="story" select="$doc/rss/channel/item">
<tr bgcolor="blue">
<td align="center">
== JSTL: for each and scoped variable ==
<!-- start source code -->
<source lang="java">
<%@ taglib prefix="c" uri="http://java.sun.ru/jstl/core" %>
<c:set var="names" value="Joe, Zhou" scope="page" />
<html>
<head>
<title>forEach and status</title>
</head>
<body>
<h1>The forEach tag exposes a scoped variable called "count", which
is the position of the current iteration of the collection.</h1>
<h2>(Note, it is <i>not</i> the position of the element in the
underlying collection)</h2>
<c:forEach items="${pageScope.names}"
var="currentName"
varStatus="status"
>
Family member #<c:out value="${status.count}" /> is
<c:out value="${currentName}" /> <br />
</c:forEach>
</body>
</html>
JSTL: for each and status
<%@ taglib prefix="c" uri="http://java.sun.ru/jstl/core" %>
<c:set var="names" value="Joe, Rob, Rosy, Sissi" scope="page" />
<html>
<head>
<title>forEach and status</title>
</head>
<body>
<h1>The forEach tag exposes a scoped variable called "count", which
is the position of the current iteration of the collection.</h1>
<h2>(Note, it is <i>not</i> the position of the element in the
underlying collection)</h2>
<c:forEach items="${pageScope.names}"
var="currentName"
varStatus="status"
begin="0"
end="3"
step="2"
>
Family member #<c:out value="${status.count}" /> is
<c:out value="${currentName}" /> <br />
</c:forEach>
</body>
</html>
JSTL: for each loop
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.ru/jstl/core_rt" prefix="c-rt" %>
<%!
String[] names = { "Joe", "Rosy", "Sissi", "Sun" };
int[] ages = {29, 8, 6, 5};
%>
<HTML>
<HEAD><TITLE>JSTL "forEach" tag</TITLE></HEAD>
<BODY>
<H1>List of people</H1>
<TABLE BORDER="1">
<TH>Name</TH>
<c-rt:forEach var="person" items="<%= names %>">
<TR>
<TD><c:out value="${person}" /></TD>
<TD><c:out value="${ages[i]}" /></TD>
</TR>
</c-rt:forEach>
</TABLE>
</BODY>
</HTML>
JSTL Form Value and ForEach Loop
<html>
<head>
<title>Page Data Example</title>
</head>
<body>
<table border="1">
<form method="POST" action="params2.jsp">
<tr>
<td width="33%">
<b>First Name</b>
</td>
<td width="73%">
<input type="text" name="first" size="40" />
</td>
</tr>
<tr>
<td width="33%">
<b>Last Name</b>
</td>
<td width="73%">
<input type="text" name="last" size="40" />
</td>
</tr>
<tr>
<td width="33%">
<b>Address</b>
</td>
<td width="73%">
<input type="text" name="address" size="40" />
</td>
</tr>
<tr>
<td width="33%">
<b>City</b>
</td>
<td width="73%">
<input type="text" name="city" size="20" />
</td>
</tr>
<tr>
<td width="33%">
<b>State</b>
</td>
<td width="73%">
<input type="text" name="state" size="20" />
</td>
</tr>
<tr>
<td width="33%">
<b>ZIP</b>
</td>
<td width="73%">
<input type="text" name="zip" size="20" />
</td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="Submit" name="action" />
<input type="reset" value="Reset" name="action" />
</td>
</tr>
</form>
</table>
</body>
</html>
/////////////////////////////////////////////////////////////////////////////////////
//File: params2.zip
JSTL: fortokens
<%@ taglib prefix="c" uri="http://java.sun.ru/jstl/core" %>
<c:set var="names" value="Joe:Petter;Ryan|John" scope="page" />
<html>
<head>
<title>forTokens action</title>
</head>
<body>
<c:forTokens items="${pageScope.names}"
delims=":;|"
var="currentName"
varStatus="status"
>
Family member #<c:out value="${status.count}" /> is
<c:out value="${currentName}" /> <br />
</c:forTokens>
</body>
</html>
JSTL Tag collaboration with a fixed loop
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.ru/jstl/core-rt" prefix="c-rt" %>
<html>
<head>
<title>Count to 10 Example(tracking even and odd)</title>
</head>
<body>
<table border="0">
<c:forEach var="i" begin="1" end="10" varStatus="status">
<jsp:useBean id="status"
type="javax.servlet.jsp.jstl.core.LoopTagStatus" />
<c-rt:choose>
<c-rt:when test="<%=status.getCount()%2==0%>">
<c:set var="color" value="#eeeeee" />
</c-rt:when>
<c-rt:otherwise>
<c:set var="color" value="#dddddd" />
</c-rt:otherwise>
</c-rt:choose>
<tr>
<td width="200" bgcolor="<c:out value="${color}"/>">
<c:out value="${i}" />
</td>
</tr>
</c:forEach>
</table>
</body>
</html>