我正在尝试在 Spring 引导应用程序中使用类型转换器并使用 Thymeleaf，但我无法使其正常工作。我在 Github 上放了一些代码，这样你就可以准确地看到我正在尝试做什么。这是 Spring 1.5.1 和 Thymeleaf 3.0.3。 https://github.com/matthewsommer/spring-thymeleaf-simple-converter
基本上这段代码只是试图将一个人添加到评论对象中。 person 对象在发布时为 null，我不明白为什么。
奇怪的是，人的 ID 没有被添加到 value 属性中，但是如果 th:field="*{body}"被删除了。我认为这与此有关:https://github.com/thymeleaf/thymeleaf/issues/495但我目前正在尝试添加 BindingResult 但它不起作用...
我的 HTML 是:
<body>
<div th:if="${personObject != null}" th:text="${personObject.name}"></div>
<form th:action="@{/}" th:object="${comment}" method="post">
<input type="hidden" th:if="${personObject != null}" th:value="${personObject.id}" th:field="*{person}" />
<textarea id="comment" placeholder="Comment..." th:field="*{body}"></textarea>
<button id="comment_submit" type="submit">Comment</button>
</form>
<div th:text="${comment.body}"></div>
</body>
我的 Controller :
@Controller
public class HomeWebController {
@RequestMapping(value = "/", method = RequestMethod.GET)
public String getHome(final HttpServletRequest request, final Map<String, Object> model, @ModelAttribute(value = "comment") Comment comment) {
model.put("personObject", new Person(1, "John Smith"));
return "Home";
}
@RequestMapping(value = "/", method = RequestMethod.POST)
public String postHome(final HttpServletRequest request, final Map<String, Object> model, @ModelAttribute(value = "comment") Comment comment) {
model.put("commentBody", comment.getBody());
model.put("person", comment.getPerson());
return "Home";
}
}
和转换器:
@Component
public class StringToPersonConverter implements Converter<String, Person> {
@Autowired
public StringToPersonConverter() { }
@Override
public Person convert(String id) {
if(id == "1") {
Person person = new Person(1, "John Smith");
return person;
}
return null;
}
}
最佳答案
您好，最后我必须做一些更改才能使其正常工作，但这是逐个类的结果。
转换器应用:
@SpringBootApplication
@Configuration
@EnableWebMvc
public class ConvertorApplication extends WebMvcConfigurerAdapter {
public static void main(String[] args) {
SpringApplication.run(ConvertorApplication.class, args);
}
//Add converter and configuration annotation
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(new StringToPersonConverter());
}
}
StringToPersonConverter:
@Override
public Person convert(String id) {
//Never compare String with == use equals, the "==" compares memory space not the values
if(id.equals("1")) {
Person person = new Person(1, "John Smith");
return person;
}
return null;
}
主页网络 Controller
@Controller
public class HomeWebController {
@RequestMapping(value = "/", method = RequestMethod.GET)
public String getHome(final Map<String, Object> model, @ModelAttribute(value = "comment") Comment comment) {
//Initialize the comment with the person inside, no need of personObject object
model.put("comment", new Comment(new Person(1, "John Smith")));
return "Home";
}
@RequestMapping(value = "/", method = RequestMethod.POST)
public String postHome(final Map<String, Object> model,
@ModelAttribute(value = "comment") Comment comment,
@RequestParam(value = "person.id") Person person) {
//from the view retrieve the value person.id which will be used by the converter to build the Person entity
comment.setPerson(person);
model.put("comment", comment);
return "Home";
}
}
注释(添加空构造函数)
public Comment(){}
人(添加空构造函数)
public Person(){}
Home.jsp(基本去掉personObject，不需要)
<!DOCTYPE html>
<html xmlns:th="//www.thymeleaf.org">
<body>
<div th:text="${comment.person.name}"></div>
<form th:action="@{/}" th:object="${comment}" method="post">
<input type="hidden" th:field="*{person.id}" />
<textarea id="comment" placeholder="Comment..." th:field="*{body}"></textarea>
<button id="comment_submit" type="submit">Comment</button>
</form>
<div th:text="${comment.body}"></div>
</body>
</html>
这就是让它发挥作用的一切。
关于Spring + Thymeleaf 形式的转换器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42215166/