title: Spring thymeleaf Form url cannot be resolved
body: <p>I want to know how to transfer parameters in spring form mvc platform.
  First, Below code is spring form java file.</p>
  
  <pre><code>public class PostForm {
  
      @NotNull
      @Size(max=30, message="type id within 30 limits")
      private String title;
  
      @NotNull
      @Size(max=100, message="type id within 100 limits")
      private String Content;
  
      public String getTitle() {
          return title;
      }
  
      public void setTitle(String title) {
          this.title = title;
      }
  
      public String getContent() {
          return Content;
      }
  
      public void setContent(String content) {
          Content = content;
      }
  }
  </code></pre>
  
  <p>And the next file is the bounded edit.html file</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html xmlns:th="http://www.thymeleaf.org"&gt;
  &lt;meta charset="UTF-8"&gt;
  &lt;title&gt;Blog modification&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
  
  &lt;h1&gt;Please, Modifiy.&lt;/h1&gt;
  &lt;form method="post" th:object="${postForm}"&gt;
      &lt;div&gt;&lt;label for="title"&gt;title&lt;/label&gt;&lt;/div&gt;
      &lt;input id="title" type="text" name="title" th:value="*{title}" /&gt;
      &lt;span class="formError" th:if="${#fields.hasErrors('title')}" th:errors="*{title}"&gt;Input title is wrong&lt;/span&gt;
  
      &lt;div&gt;&lt;label for="content" th:value="*{title}"&gt;Content&lt;/label&gt;&lt;/div&gt;
      &lt;textarea name="content" rows="20" width="200" th:value="*{content}"&gt;&lt;/textarea&gt;
      &lt;span class="formError" th:if="${#fields.hasErrors('content')}" th:errors="*{content}"&gt;Input content is wrong&lt;/span&gt;
  
      &lt;div&gt;
          &lt;input type="submit" value="Modify" /&gt;
          &lt;a href="index.html" th:href="@{/posts}"&gt;Cancel&lt;/a&gt;
      &lt;/div&gt;
  &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Input link url to form is like below,</p>
  
  <pre><code>    &lt;td&gt;
          &lt;a href="posts/edit.html" th:href="@{posts/edit/__${post.id}__}"&gt;edit&lt;/a&gt;&lt;br/&gt;
          &lt;a href="posts/edit.html" th:href="@{posts/edit/__${post.id}__}"&gt;delete&lt;/a&gt;
      &lt;/td&gt;
  </code></pre>
  
  <p>But the exception is thrown in the spring mvc controller codes.</p>
  
  <pre><code>@RequestMapping("/posts/edit/{id}")
      public String edit(PostForm postForm) {
          return "posts/edit/{id}"; //This line throws exception.
      }
  
  @RequestMapping(value="/posts/edit/{id}", method = RequestMethod.POST)
      public String edit(@PathVariable("id") Long id, @Valid PostForm postForm, BindingResult bindingResult) {
  
          Post p = postService.findById(id);
          postForm.setTitle(p.getTitle());
          postForm.setContent(p.getBody());
  
          .....
  </code></pre>
  
  <p>The exception is</p>
  
  <pre><code>ERROR 4024 --- [nio-8080-exec-4] org.thymeleaf.TemplateEngine             : [THYMELEAF][http-nio-8080-exec-4] Exception processing template "posts/edit/{id}": Error resolving template "posts/edit/{id}", template might not exist or might not be accessible by any of the configured Template Resolvers
  
  org.thymeleaf.exceptions.TemplateInputException: Error resolving template "posts/edit/{id}", template might not exist or might not be accessible by any of the configured Template Resolvers
      at org.thymeleaf.engine.TemplateManager.resolveTemplate(TemplateManager.java:870) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
      at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:607) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
      at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) [thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
      at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) [thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
  </code></pre>
  
  <p>I have no idea how to transfer parameter in Spring Thymeleaf form template.</p>