Java 如何将多个下拉列表绑定到model-spring mvc

JSP

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

和在控制器中

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

@RequestMapping(value = "/manualbooking.htm", method = RequestMethod.POST)
    public String doManualBooking(HttpServletRequest httpServletRequest,
            PassengerDetailDTO passengerDetailDTO,  ModelMap map) {
        LOGGER.info("Manual Booking Request");

        LOGGER.info(passengerDetailDTO.toString());

        return "manualbooking";
    }

当有多个下拉框时，提交表单后，要求始终为空。如何解决此问题？

确保您的

框名称代表数组

[]

。例如：

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

<select name="requirements[0]" ..>

<select name="requirements[1]" ..>

---

检查此演示：。

您可以向支持bean添加两个不同的字符串字段，即

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

private String requirement1;
private String requirement2;

然后使用与此类似的构造

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

 <form:select path="requirement1" multiple="false" id="requirement1">
    <form:options items="${yourRequirementsAsACollection}" />
 </form:select>


 <form:select path="requirement2" multiple="false" id="requirement2">
    <form:options items="${yourRequirementsAsACollection}" />
 </form:select>

将所选值分别写入第一个或第二个字段

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

另一方面，您可以使用多选框，在这种情况下，所有选定的值将在单个字段中以逗号分隔

<select name="requirements"  style="width:150px;" id="requirements1">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select>
<select name="requirements"  style="width:150px;" id="requirements2">
                                        <option selected="selected" value="o Special Assistance">No Special Assistance</option>
                                        <option value="Assistance climbing steps">Assistance climbing steps</option>
                                        <option value="Assistance within the plane">Assistance within the plane</option>
                                        <option value="Blind passenger">Blind passenger</option>
                                        <option value="Hearing impaired">Hearing impaired</option>
                                        <option value="Wheelchair within terminal">Wheelchair within terminal</option>
                                    </select><input type="text" name="specialrequest" id="specialrequest1" />
        </form>

 private String requirements; // Ends up comma-separated, ie "req1, req2"


 <form:select path="requirements" multiple="true" id="requirements">
    <form:options items="${yourRequirementsAsACollection}" />
 </form:select>

私有字符串要求；//以逗号分隔结束，即“req1，req2”

是已定义的选择数（例如2），还是该数字是可变的？这很难管理，您可以查看可能的解决方案。