thymeleaf の th:field th:each th:object のあたりのメモ #Java

thymeleaf-spring4-2.1.5.RELEASE で

<select th:field="*{income}">
  <option th:each="item : ${income_list}" th:object="${item}" th:value="*{code}">
    <span th:text="*{name}"></span>
  </option>
</select>

が

ERROR 44072 --- [nio-8091-exec-1] org.thymeleaf.TemplateEngine             : [THYMELEAF][http-nio-8091-exec-1] Exception processing template "hoge/index": Error during execution of processor 'org.thymeleaf.spring4.processor.attr.SpringOptionFieldAttrProcessor' (hoge/index)
ERROR 44072 --- [nio-8091-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateProcessingException: Error during execution of processor 'org.thymeleaf.spring4.processor.attr.SpringOptionFieldAttrProcessor' (hoge/index)] with root cause

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'item' available as request attribute

というエラーになる。前から？

<select th:field="*{income}">
  <option th:each="item : ${income_list}" th:value="${item.code}">
    <span th:text="${item.name}"></span>
  </option>
</select>

と治したら動いた。

ちなみに、select の th:field="*{income}" を外すと動く。

メモで。