Spring @ModelAttribute，http post参数转换失败

Question

我在尝试提交 html 选项选择表单时收到以下错误，所选选项值未转换为受尊重的枚举类型。

无法将类型“java.lang.String”的属性值转换为属性“portalLayoutLocation”所需的类型“net.mis.lookup.model.PortalLayoutLocation”；嵌套异常是 java.lang.IllegalStateException：无法将类型 [java.lang.String] 的值转换为属性“portalLayoutLocation”所需的类型 [net.mis.lookup.model.PortalLayoutLocation]：找不到匹配的编辑器或转换策略

<select name="portalLayoutLocation" id="portalLayoutLocation">
<option value="">Choose a PortalLayoutLocation</option>
<option value="1">PortalLayoutLocation.HEADER_MAIN_LOGO</option>
<option value="2">PortalLayoutLocation.HOMEPAGE_TECHNICAL_TIP_OF_THE_DAY</option
<option value="3">PortalLayoutLocation.HOMEPAGE_CARTOON_OF_THE_DAY</option>
<option value="4">PortalLayoutLocation.FOOTER_LOGO</option>
<option value="5">PortalLayoutLocation.PORTAL_HEADER_MAIN_ADVERTISEMENT</option>
<option value="6">PortalLayoutLocation.PORTALHOMELAYOUT_HOMECONTENT_ADVERTISEMENT</option>
<option value="7">PortalLayoutLocation.PORTALHOMELAYOUT_WIDESIDEBAR_ADVERTISEMENT</option>
<option value="8">PortalLayoutLocation.PORTALLAYOUT_NARROWSIDEBAR_ADVERTISEMENT</option>
</select>



public enum PortalLayoutLocation {

    HEADER_MAIN_LOGO(1, "PortalLayoutLocation.HEADER_MAIN_LOGO"),
    HOMEPAGE_TECHNICAL_TIP_OF_THE_DAY(2, "PortalLayoutLocation.HOMEPAGE_TECHNICAL_TIP_OF_THE_DAY"),
    HOMEPAGE_CARTOON_OF_THE_DAY(3, "PortalLayoutLocation.HOMEPAGE_CARTOON_OF_THE_DAY"),
    FOOTER_LOGO(4, "PortalLayoutLocation.FOOTER_LOGO"),
    PORTAL_HEADER_MAIN_ADVERTISEMENT(5, "PortalLayoutLocation.PORTAL_HEADER_MAIN_ADVERTISEMENT"),
    PORTALHOMELAYOUT_HOMECONTENT_ADVERTISEMENT(6, "PortalLayoutLocation.PORTALHOMELAYOUT_HOMECONTENT_ADVERTISEMENT"),
    PORTALHOMELAYOUT_WIDESIDEBAR_ADVERTISEMENT(7, "PortalLayoutLocation.PORTALHOMELAYOUT_WIDESIDEBAR_ADVERTISEMENT"),
    PORTALLAYOUT_NARROWSIDEBAR_ADVERTISEMENT(8, "PortalLayoutLocation.PORTALLAYOUT_NARROWSIDEBAR_ADVERTISEMENT");

    private int typeCode;
    private String messageKey;

    private PortalLayoutLocation(int typeCode, String messageKey) {
        this.typeCode = typeCode;
        this.messageKey = messageKey;
    }

    public int toInt() {
        return typeCode;
    }

    public static PortalLayoutLocation fromInt(int value) {
        switch (value) {
            case 0:
                return null;
            case 1:
                return HEADER_MAIN_LOGO;
            case 2:
                return HOMEPAGE_TECHNICAL_TIP_OF_THE_DAY;
            case 3:
                return HOMEPAGE_CARTOON_OF_THE_DAY;
            case 4:
                return FOOTER_LOGO;
            case 5:
                return PORTAL_HEADER_MAIN_ADVERTISEMENT;
            case 6:
                return PORTALHOMELAYOUT_HOMECONTENT_ADVERTISEMENT;
            case 7:
                return PORTALHOMELAYOUT_WIDESIDEBAR_ADVERTISEMENT;
            case 8:
                return PORTALLAYOUT_NARROWSIDEBAR_ADVERTISEMENT;
            default:
                throw new UnsupportedOperationException("Unexpected enum value : " + value);
        }
    }

    public int getTypeCode() {
        return typeCode;
    }

    public String getMessageKey() {
        return messageKey;
    }

    public String getLocalozedMessage() {
        return StaticMessageSource.getMessage(messageKey);
    }

    @Override
    public String toString() {
        return getLocalozedMessage();
    }
}

Answer 1

使用 HEADER_MAIN_LOGO, HOMEPAGE_TECHNICAL_TIP_OF_THE_DAY, ... 作为值，而不是 1, 2, ...