在邏輯標記庫中定義了<logic:iterate>標記，它能夠根據特定集合中元素的數目對標記體的內容進行重複的檢查。集合的類型可以是java.util.Iterator,java.util.Collection,java.util.Map
或是一個陣列，也可以用name屬性定義一個bean,並且使用property屬性指定要迴圈的bean的屬性（這個屬性返回集合）類型。
下面請看struts1.2.4中自帶的例子：
<%@ taglib uri="/tags/struts-bean" prefix="bean" %>
<%@ taglib uri="/tags/struts-logic" prefix="logic" %>
<html>
<head>
<title>測試struts-logic Iterate 標記</title>
</head>
<body bgcolor="white">
<%
{
java.util.ArrayList list = new java.util.ArrayList();
list.add("First");
list.add("Second");
list.add("Third");
list.add("Fourth");
list.add("Fifth");
pageContext.setAttribute("list", list, PageContext.PAGE_SCOPE);
int intArray[] = new int[]
{ 0, 10, 20, 30, 40 };
pageContext.setAttribute("intArray", intArray, PageContext.PAGE_SCOPE);
}
%>
<div align="center">
<h1>測試struts-logic Iterate標記</h1>
</div>
<jsp:useBean id="bean" scope="page" class="org.apache.struts.webapp.exercise.TestBean" />
<jsp:useBean id="list" scope="page" class="java.util.ArrayList" />
<h3>測試1 - 從頭到尾疊代（迴圈）一個字串陣列[0..4]</h3>
<ul>
<!--用name屬性指定一個bean,property屬性指定要迴圈的bean的屬性,id集合中當前元素的控制碼，index1保存當前索引值-->
<logic:iterate id="element" name="bean" property="stringArray" indexId="index1">
<li>
<em>
<bean:write name="element" />
</em> [
<bean:write name="index1" />]</li>
</logic:iterate>
</ul>
<h3>測試2 - 疊代一個字串陣列（迴圈三次）Array [0..2]</h3>
<ul>
<logic:iterate id="element" name="bean" property="stringArray" indexId="index" length="3">
<li>
<em>
<bean:write name="element" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試3 - 疊代一個String Array [3..4]（輸出索引從3開始的元素）</h3>
<ul>
<logic:iterate id="element" name="bean" property="stringArray" indexId="index" offset="3">
<li>
<em>
<bean:write name="element" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試4 - 疊代一個String Array [1..3]</h3>
<ul>
<logic:iterate id="element" name="bean" property="stringArray" indexId="index" offset="1" length="3">
<li>
<em>
<bean:write name="element" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試5 - 從頭至尾疊代一個Array List</h3>
<ul>
<logic:iterate id="item" name="list" indexId="index">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試6 - 疊代一個Array List [0..2]</h3>
<ol>
<logic:iterate id="item" name="list" indexId="index" offset="0" length="3">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ol>
<h3>測試7 - 疊代一個Array List [2..4]</h3>
<ol>
<logic:iterate id="item" name="list" indexId="index" offset="2" length="3">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ol>
<h3>測試8 - 疊代一個int array</h3>
<ul>
<logic:iterate id="item" name="intArray" indexId="index">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試 9 - 疊代一個int array [0..2]</h3>
<ul>
<logic:iterate id="item" name="intArray" indexId="index" length="3">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
<h3>測試10 - 疊代一個int array [2..4]</h3>
<ul>
<logic:iterate id="item" name="intArray" indexId="index" offset="2" length="3">
<li>
<em>
<bean:write name="item" />
</em> [
<bean:write name="index" />]</li>
</logic:iterate>
</ul>
</body>
</html>
下麵是TestBean.java的部分：
package org.apache.struts.webapp.exercise;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Vector;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.util.LabelValueBean;
public class TestBean extends ActionForm {
//省略......................................................
private String stringArray[] =
{ "String 0", "String 1", "String 2", "String 3", "String 4" };
public String[] getStringArray() {
return (this.stringArray);
}
public void setStringArray(String stringArray[]) {
this.stringArray = stringArray;
}
//省略........................................................
}
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