我<input type="date" ...>為 Spring Boot 應用程序創建了一個簡單的表單。我想把它變成LocalDate控制器中的一個。我收到錯誤：Fri Aug 17 15:32:01 CEST 2018There was an unexpected error (type=Internal Server Error, status=500).No primary or default constructor found for class java.time.LocalDate這當然是正確的，但是 - 據我所知 - 應該無關緊要，因為根據文檔：“[...]@DateTimeFormat注釋應該適用java.time于 Java 8 和 Spring 4?！笨刂破鞣椒ǎ篅PostMapping("/users")public String register(String user, String pw, @DateTimeFormat(iso=DateTimeFormat.ISO.DATE) LocalDate beginning){    MyUser myUser = MyUser.create(user,pw);    MyUser.setEnabled(beginning);    repo.register(myUser);    return "redirect:/users/"+user;}HTML/百里香葉：<form method="POST"><div><label> Benutzername : <input type="text" name="user"/> </label></div><div><label> Passwort: <input type="password" name="password"/> </label></div><div><label> Freigeschaltet ab (optional): <input type="date" name="beginning"/> </label></div><div><input type="submit" value="Registrieren"/></div></form>pom（摘錄） <dependencyManagement>    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-dependencies</artifactId>            <version>2.0.4.RELEASE</version>            <type>pom</type>            <scope>import</scope>        </dependency>    </dependencies></dependencyManagement><dependencies>    <dependency>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-thymeleaf</artifactId>    </dependency>    <dependency>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-web</artifactId>    </dependency>...</dependencies>   <properties>    <java.version>1.8</java.version></properties>