当其中一个字段不是字符串而是另一个对象时，如何用Spring MVC提交表单？

Question

    <form:form method="post" action="addNewWord.html" commandName="word" >

    <table>


    //many other fields;    


        <tr>
            <td>Category:</td>
            <td><form:select path="category" items="${CATEGORIES}"
                    var="cat">
                </form:select></td>
            <td><form:errors path="category" cssClass="error" /></td>
        </tr>


        <tr>
            <td colspan="2"><input type="submit" value="Add new word" /></td>
        </tr>
    </table>

</form:form>

@Entity
@Table(name = "word")
public class Word {

    //other instance variables either primitives or Strings;

    @Column(name = "category", nullable = false, length = 80)
    private String  category;
        //getters-setters 

    @ManyToOne
@JoinColumn(name = "category_id")
private Category category;

我应该如何修改.jsp文件上的表单以提交包含不是字符串而是类别的字段的word对象？就整个情况而言，让我展示由提交调用的控制器中的方法：

@RequestMapping(value = "/addNewWord", method = RequestMethod.POST)
public String addNewWord(@ModelAttribute Word word, BindingResult result, Model model) {
    WordValidator validator = new WordValidator();
    validator.validateWord(word, result, wordService.getAllWord(), categoryService.getAllCategories());
    if (!result.hasErrors()) {
        wordService.save(word);
        word.clearValues();
    }
    fillCategoryNames(model);
    return "addNew";
}

我有一种感觉，我应该使用@InitBinder方法，但我不知道如何使用，这更像是一种感觉，而不是坚如磐石的事实。欢迎任何建议。

Answer 1

给你：

public class CategoryEditor extends PropertyEditorSupport {

    // Converts a String to a Category (when submitting form)
    @Override
    public void setAsText(String text) {
        Category c = new Category();
        c.setName(text);
        this.setValue(c);
    }

    // Converts a Category to a String (when displaying form)
    @Override
    public String getAsText() {
        Category c = (Category) this.getValue();
        return c.getName();
    }

}

而且

...
public class MyController {

    @InitBinder
    public void initBinder(WebDataBinder binder) {
        binder.registerCustomEditor(Category.class, new CategoryEditor());
    }

    ...

}

Fore更多信息：

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