在JSP中的ArrayList迭代 [英] Iterate ArrayList in JSP
问题描述
我在我的类中的两个的ArrayList,我想将它发送给我的JSP,然后遍历数组列表中的元素在选择标签。
I have two arraylists in my class and I want to send it to my JSP and then iterate the elements in arraylist in a select tag.
下面是我的类:
package accessData;
import java.util.ArrayList;
public class ConnectingDatabase
{
ArrayList<String> food=new ArrayList<String>();
food.add("mango");
food.add("apple");
food.add("grapes");
ArrayList<String> food_Code=new ArrayList<String>();
food.add("man");
food.add("app");
food.add("gra");
}
我要遍历food_ code作为选择标记和食物在JSP标签中选择选项的值;我的JSP是:
I want to iterate food_Code as options in select tag and food as values in Select tag in JSP; my JSP is:
<select id="food" name="fooditems">
// Don't know how to iterate
</select>
任何一件code是高度AP preciated。在此先感谢:)
Any piece of code is highly appreciated. Thanks in Advance :)
推荐答案
这将是更好地使用的java.util.Map
来存储密钥和价值观,而不是两个的ArrayList
,如:
It would be better to use a java.util.Map
to store the key and values instead of two ArrayList
, like:
Map<String, String> foods = new HashMap<String, String>();
// here key stores the food codes
// and values are that which will be visible to the user in the drop-down
foods.put("man", "mango");
foods.put("app", "apple");
foods.put("gra", "grapes");
// if this is your servlet or action class having access to HttpRequest object then
httpRequest.setAttribute("foods", foods); // so that you can retrieve in JSP
现在迭代地图在JSP使用:
Now to iterate the map in the JSP use:
<select id="food" name="fooditems">
<c:forEach items="${foods}" var="food">
<option value="${food.key}">
${food.value}
</option>
</c:forEach>
</select>
或者不JSTL:
Or without JSTL:
<select id="food" name="fooditems">
<%
Map<String, String> foods = (Map<String, String>) request.getAttribute("foods");
for(Entry<String, String> food : foods.entrySet()) {
%>
<option value="<%=food.getKey()%>">
<%=food.getValue() %>
</option>
<%
}
%>
</select>
要了解更多关于JSTL迭代这里是一个很好的<一个href=\"http://stackoverflow.com/questions/2117557/how-to-iterate-an-arraylist-inside-a-hashmap-using-jstl\">SO回答这里是一个很好的教程有关如何在一般的使用JSTL。
To know more about iterating with JSTL here is a good SO answer and here is a good tutorial about how to use JSTL in general.
这篇关于在JSP中的ArrayList迭代的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!