java - Struts 2 迭代器标签

Question

我有一个 Java Bean 集合，我想使用迭代器标记在 JSP 中对其进行迭代。

列表按此标签排序的默认顺序是什么？因为它不按照 Bean 在列表中添加的顺序进行迭代。

这是struts Action 类代码:

public String getUsersTraceJSP() {

    try {

        Map session = ActionContext.getContext().getSession();
        Properties properties = new Properties();
        InitialContext ic = new InitialContext(properties);
        PartnerSessionBeanRemote bIRemote = (PartnerSessionBeanRemote) ic.lookup(PartnerSessionBeanRemote.class.getName());

        UserLoginTraceForm ultf = bIRemote.getUserLoginTrace(Long.parseLong(userId));

        for (UserLoginTraceForm uu : ultf.getUltList()) {
            System.out.println("ULT ID | " + uu.getUltId());
        }

        session.put("ULTF", ultf);

    } catch (Exception e) {
        e.printStackTrace();
        Logger.printError("ERROR", "AppFilesAction.getUsersTraceJSP() ", e);
    }

    return "success";
}

System.out.println("ULT ID | "+ uu.getUltId()) 给出以下输出:

INFO:   ULT ID | 91
INFO:   ULT ID | 9
INFO:   ULT ID | 86
INFO:   ULT ID | 84
INFO:   ULT ID | 83
INFO:   ULT ID | 82
INFO:   ULT ID | 81
INFO:   ULT ID | 8
INFO:   ULT ID | 74
INFO:   ULT ID | 73
INFO:   ULT ID | 72
INFO:   ULT ID | 71
INFO:   ULT ID | 70
INFO:   ULT ID | 7
INFO:   ULT ID | 69
INFO:   ULT ID | 68
INFO:   ULT ID | 67
INFO:   ULT ID | 66
INFO:   ULT ID | 65
INFO:   ULT ID | 64
INFO:   ULT ID | 63
INFO:   ULT ID | 62
INFO:   ULT ID | 61
INFO:   ULT ID | 6
INFO:   ULT ID | 5
INFO:   ULT ID | 49
INFO:   ULT ID | 48
INFO:   ULT ID | 47
INFO:   ULT ID | 46
INFO:   ULT ID | 45
INFO:   ULT ID | 44
INFO:   ULT ID | 43
INFO:   ULT ID | 42
INFO:   ULT ID | 41
INFO:   ULT ID | 40
INFO:   ULT ID | 4
INFO:   ULT ID | 39
INFO:   ULT ID | 38
INFO:   ULT ID | 37
INFO:   ULT ID | 36
INFO:   ULT ID | 35
INFO:   ULT ID | 34
INFO:   ULT ID | 33
INFO:   ULT ID | 32
INFO:   ULT ID | 31
INFO:   ULT ID | 30

JSP 是:

输出是这样的:

<div class="row" style="height:92.5%;padding-left: 1%;padding-right: 1%;overflow: auto">
    <div id="tableDiv" >

        <table id="formList" class="display" cellspacing="0" width="100%">
            <thead style="background-color: #BDC6E7">
                <tr>
                    <th>ultId>
                    <th>Login Time</th>
                    <th>IP Address</th>

                </tr>
            </thead>
            <tbody>


                <s:iterator value="#session.ULTF.ultList">
                    <tr>

                        <td><s:property value="ultId"/></td>
                        <td><s:property value="loginTime"/></td>
                        <td><s:property value="ipAddress"/></td>                 

                    </tr>
                </s:iterator>
            </tbody>
        </table>



    </div>

</div>

Answer 1

如果您需要一个保留其元素插入顺序的Collection，请使用本质上有序的List，或者以Linked 开头的类，如 LinkedHashSet、LinkedHashMap 等...这正是它们与其他实现的不同之处。了解更多 this answer .