jsp 오류

오류 내용:

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'researchList[${num}]' available as request attribute

상황:

select박스 값이 변동되면 onchange로 바로 함수를 호출해서 innerHtml로 용도에 맞게 테이블을 변경하려고 했다.

//selectBox가 변경시 이벤트 감지
function chageLangSelect(num,selectVal){
	var tableId = "search_table_"+num;				//테이블 id
	var selectId = "researchList["+num+"].reType";	//셀렉트 박스 id

	if (selectVal == '0') {
		alert("라디오박스");
		
 		var innerHtml =`
						<table class="tbl_row_type01" id="search_table_\${num}"> 
							<caption>내용(제목, 작성자, 작성일 등으로 구성)</caption>
							<colgroup>
								<col style="width:20%;">
								<col style="width:30%;">
								<col style="width:20%;">
								<col style="width:30%;">
							</colgroup> 
							<tbody id="sub_tbody_\${num}">
								<tr>
									<th scope="row"><strong class="th_tit">설문 타입</strong></th>
									<td colspan="3">
										<select name="researchList[\${num}].reType" id="researchList[\${num}].reType" title="설문 타입" cssClass="w100">
											<option value="0" label="라디오박스" selected="selected"/>
											<option value="1" label="이미지"/>
											<option value="2" label="체크박스"/>
										</select>
									</td>
								</tr>
								<tr>
									<th scope="row"><strong class="th_tit">설문 제목</strong></th>
									<td colspan="3">
										<input type="text" name="researchList[\${num}].reTitle" class="text w50p" required="required"  maxlength="50"/>
										<a href="#" class="btn btn_mdl btn_save">항목 추가</a>
									</td>
								</tr>
								<tr id="add_tr_1">
									<th scope="row"><strong class="th_tit">설문 내용</strong></th>
									<td colspan="3" class="search_cont">
										<input type="radio" name="researchList[0].check" id="researchList[0].check" value="0" />
										<input type="text" name="researchList[0].reCont" id="researchList[0].reCont" class="text w50p" required="required"  maxlength="50"/>
										<a href="#" class="btn btn_i_del"><span>삭제</span></a>
									</td> 
								</tr>
								<tr id="add_tr_2">
									<th scope="row"></th>
									<td colspan="3" class="search_cont">
										<input type="radio" name="researchList[1].check" id="researchList[1].check" value="0" />
										<input type="text" name="researchList[1].reCont" id="researchList[1].reCont" class="text w50p" required="required"  maxlength="50"/>
										<a href="#" class="btn btn_i_del"><span>삭제</span></a>
									</td> 
								</tr>
							</tbody>
						</table>
						`; 
		$("#research_tables>tbl_wrap:last").append(innerHtml);
	}
		
}

<table class="tbl_row_type01" id="search_table_1"> 
	<caption>내용(제목, 작성자, 작성일 등으로 구성)</caption>
	<colgroup>
		<col style="width:20%;">
		<col style="width:30%;">
		<col style="width:20%;">
		<col style="width:30%;">
	</colgroup> 
	<tbody id="sub_tbody_1">
		<tr>
			<th scope="row"><strong class="th_tit">설문 타입</strong></th>
			<td colspan="3">
				<form:select path="researchList[0].reType" id="researchList[0].reType" onchange="chageLangSelect('1',this.value)" title="설문 타입" cssClass="w100">
					<form:option value="0" label="라디오박스"/>
					<form:option value="1" label="이미지"/>
					<form:option value="2" label="체크박스"/>
				</form:select>
			</td>
		</tr>
		<tr>
			<th scope="row"><strong class="th_tit">설문 제목</strong></th>
			<td colspan="3">
				<input type="text" name="researchList[0].reTitle" class="text w50p" required="required"  maxlength="50"/>
				<a href="#" class="btn btn_mdl btn_save" onclick="fncAdd('1');">항목 추가</a>
			</td>
		</tr>
		<tr id="add_tr_1">
			<th scope="row"><strong class="th_tit">설문 내용</strong></th>
			<td colspan="3" class="search_cont">
				<input type="radio" name="researchList[0].check" id="researchList[0].check" value="0" />
				<input type="text" name="researchList[0].reCont" id="researchList[0].reCont" class="text w50p" required="required"  maxlength="50"/>
				<a href="#" class="btn btn_i_del" onclick="fncDel('1','1');"><span>삭제</span></a>
			</td> 
		</tr>
	</tbody>
</table>

해결

문제는 innerHtml에 form:form 태그가 새용되면서 오류가 난 것.
- 변경 전 -

<form:select path="researchList[\${num}].reType" id="researchList[\${num}].reType" onchange="chageLangSelect('\${num}',this.value)" title="설문 타입" cssClass="w100">
  <form:option value="0" label="라디오박스" selected="selected"/>
  <form:option value="1" label="이미지"/>
  <form:option value="2" label="체크박스"/>
</form:select>

- 변경 후 -

<select name="researchList[\${num}].reType" id="researchList[\${num}].reType" onchange="chageLangSelect('\${num}',this.value)" title="설문 타입" cssClass="w100">
  <option value="0" label="라디오박스" selected="selected"/>
  <option value="1" label="이미지"/>
  <option value="2" label="체크박스"/>
</select>