Struts2选择标签保存和调用问题

Question

我在尝试使用 struts2 标签时感到困惑。我遵循了几个示例，它们似乎都有相同的使用模式，但这对我不起作用（下面是所有相关的代码）。

基本上，struts2 选择下拉列表允许我显示初始列表并保存值，但当我打开页面编辑对象时，无法正确显示。显示页面后，所有选择值都会显示默认值而不是预期值。如果我修改选择值并再次保存页面，它将正确保存该值。在某个地方，标记未正确设置选项列表的 SELECTED 值。我能够查看保存到数据库的正确更改，因此我知道该操作正在正确接收对象。

我相信问题出在 行，但我可能是错的。看起来这个页面的所有部分都有效，除了在调用对象时设置下拉菜单的正确值之外。

我期望这个

public class MemberAction
    extends AbstractAction<Member>
{
    private static final long serialVersionUID = 1L;
    private Service<LifeInsuranceStatus> lifeInsuranceStatusService;

    // Code removed for brevity...

    public List<LifeInsuranceStatus> getLifeInsuranceStatuses()
    {
        return lifeInsuranceStatusService.getObjects().getResponse();
    }

    public Service<LifeInsuranceStatus> getLifeInsuranceStatusService()
    {
        return lifeInsuranceStatusService;
    }

    public void setLifeInsuranceStatusService(Service<LifeInsuranceStatus> lifeInsuranceStatusService)
    {
        this.lifeInsuranceStatusService = lifeInsuranceStatusService;
    }
}

JSP 页面如下所示：

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags" %>

<s:form action="saveMember" method="post">
<table border="1">
    <tr>
        <td>
            <s:text name="domainObject.lifeInsuranceCoveragesn.lifeInsuranceStatus.status" />
        </td>
    </tr>
    <s:div id="LifeInsuranceCoverages" theme="simple">
        <s:iterator value="domainObject.lifeInsuranceCoverages" status="status">
            <tr class="lifeInsuranceCoverageRow<s:property value="%{#status.index}" />">
                <td>
                    <s:select list="lifeInsuranceStatuses" name="domainObject.lifeInsuranceCoverages[%{#status.index}].lifeInsuranceStatus.oid" listKey="oid" listValue="status" theme="simple" />
                </td>
            </tr>
        </s:iterator>
    </s:div>

    <tr id="addLifeInsuranceCoverageRow">
        <td>
            <a href="#" onClick="return LifeInsuranceCoverages.addRow()">Add Life Insurance Coverage...</a>
        </td>
    </tr>
</table>

<s:submit key="submit" />
</s:form>

我的模型如下所示：

public class Member
    extends Person
{
    private static final long serialVersionUID = 1L;

    private List<LifeInsuranceCoverage> lifeInsuranceCoverages;

    public List<LifeInsuranceCoverage> getLifeInsuranceCoverages()
    {
        if (lifeInsuranceCoverages == null)
        {
            lifeInsuranceCoverages = new ArrayList<LifeInsuranceCoverage>();
        }

        return lifeInsuranceCoverages;
    }

    public LifeInsuranceCoverage getActiveLifeInsuranceCoverage()
    {
        if (lifeInsuranceCoverages == null || lifeInsuranceCoverages.size() < 1)
        {
            return null;
        }
        else
        {
            return lifeInsuranceCoverages.get(lifeInsuranceCoverages.size() - 1);
        }
    }

    public void setLifeInsuranceCoverages(List<LifeInsuranceCoverage> lifeInsuranceCoverages)
    {
        this.lifeInsuranceCoverages = lifeInsuranceCoverages;

        for (LifeInsuranceCoverage lifeInsuranceCoverage : this.lifeInsuranceCoverages)
        {
            lifeInsuranceCoverage.setMember(this);
        }
    }

    public void addLifeInsuranceCoverage(LifeInsuranceCoverage lifeInsuranceCoverage)
    {
        lifeInsuranceCoverage.setMember(this);
        getLifeInsuranceCoverages().add(lifeInsuranceCoverage);
    }

    public void removeLifeInsuranceCoverage(LifeInsuranceCoverage lifeInsuranceCoverage)
    {
        getLifeInsuranceCoverages().remove(lifeInsuranceCoverage);
        lifeInsuranceCoverage.setMember(null);
    }
}

... 和 ...

public class LifeInsuranceCoverage
    extends AbstractDomainObject
{
    private static final long serialVersionUID = 1L;
    private Member member;
    private LifeInsuranceStatus lifeInsuranceStatus;

    public LifeInsuranceStatus getLifeInsuranceStatus()
    {
        return lifeInsuranceStatus;
    }

    public void setLifeInsuranceStatus(LifeInsuranceStatus lifeInsuranceStatus)
    {
        this.lifeInsuranceStatus = lifeInsuranceStatus;
    } 

    public Member getMember()
    {
        return member;
    }

    public void setMember(Member member)
    {
        this.member = member;
    }
}

... 和 ...

public class LifeInsuranceStatus
    extends AbstractDomainObject
{
    private static final long serialVersionUID = 1L;
    private String status;

    public String getStatus()
    {
        return status;
    }

    public void setStatus(String status)
    {
        this.status = status;
    }
}

... 以及 ...

public abstract class AbstractDomainObject
    implements DomainObject
{
    private static final long serialVersionUID = 1L;
    private Long oid;

    public Long getOid()
    {
        return oid;
    }

    public void setOid(Long oid)
    {
        this.oid = oid;
    }
}

Answer 1

经过一番尝试和错误后，我能够解决这个问题。我找到的解决方案对我来说没有意义，但无论如何它都有效。

为了解决这个问题，我必须做两件事。首先，我在 LifeInsuranceStatus 类中添加了一个 toString() 方法，该方法仅返回 status 值。然后我删除了 struts2 标签的 listKey 部分。一旦我同时完成这两件事，我存储在数据库中的值就会被正确调用并正确保存。

我很想知道为什么会这样。任何人都对 struts2 标签有更好的了解，或者为什么另一个使用枚举的下拉菜单在不删除标签的 listKey 部分的情况下工作得很好......