Question

我正在尝试使用SpringBoot，Hibernate和Thymeleaf构建应用程序。

我想使用Thymeleaf在服务列表中获取选定服务的“ id”，在数据库中搜索该服务，然后将其定向转到另一个页面，该页面根据所选列表项显示服务的详细信息，但是我收到以下错误消息：

 EL1007E: Property or field 'name' cannot be found on null

显然，我在Thymeleaf的服务列表中获得了所选服务的“ id”。我不知道这是否正确，但是“ productdetail”页面网址中至少出现了所选的服务ID。

查看产品详细信息

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
  <head>
     <meta charset="UTF-8">
     <title>Insert title here</title>
  </head>
<body>
  <h1>Product Detail</h1>

  <p>Name: </p>
  <p th:text="${service.name}"></p>
</body>
</html>

查看index.html：

 <!DOCTYPE html>
 <html xmlns:th="http://www.thymeleaf.org">
   <head>
     <meta charset="UTF-8" />
     <title>Insert title here</title>
     <link rel="stylesheet" href="css/style.css" type="text/css" />      
  </head>
 <body>
    <div id="wrapper">
       <header id="home">
           <div id="serviceGalery">
              <div class="service" th:each="service : ${services}" >
                 <p th:text="${service.name}"></p>
                 <p th:text="${service.description}"></p>             
                 <p th:value="${service.id}" ></p>
                 <p th:text="${service.grade}"></p>
                 <a th:href="@{/productdetail/{id}(id = ${service.id}) }">Buy</a>
             </div>
         </div> 
       </header>  
    </div> 
 </body>
 </html>

控制器

@Controller
public class ServiceController {

@Autowired
private ServiceRepository repository;

    @RequestMapping("/")
public String index(Model model) {

    Iterable<Service> services = repository.findAll();

    model.addAttribute("services", services);

    return "index";
}


@RequestMapping(value = "/productdetail/{id}", method = RequestMethod.GET)
public String productDetail(@PathVariable("id") Long serviceId) {

    Optional<Service> service = repository.findById(serviceId);
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.addObject("service", service);

    System.out.println("teste: " + serviceId);

    return "productdetail";
}

型号

package com.markus.getachef.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity(name="servico")
public class Service {

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
private String name;
private String grade;
private String description;

public Service() {

    public Service(String name, String grade, String description) {
        super();
        this.name = name;
        this.grade = grade;
        this.description = description;
    }


    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getGrade() {
        return grade;
    }
    public void setGrade(String grade) {
        this.grade = grade;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }

}

存储库

package com.markus.getachef.repository;

import org.springframework.data.repository.CrudRepository;

import com.markus.getachef.model.Service;

public interface ServiceRepository extends CrudRepository<Service, Long>{

}

有人可以告诉我正确的方法吗？

Answer 1

实际上，您在控制器中犯了一个愚蠢的错误

@RequestMapping(value = "/productdetail/{id}", method = RequestMethod.GET)
public String productDetail(@PathVariable("id") Long serviceId) {

    Optional<Service> service = repository.findById(serviceId);
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.addObject("service", service);

    System.out.println("teste: " + serviceId);

    return "productdetail";
}

您正在定义模型和视图。根据您的要求，您的控制器将类似于

@RequestMapping(value = "/productdetail/{id}", method = RequestMethod.GET)
public String productDetail(@PathVariable("id") Long serviceId, Model model) {

    Service service = repository.getFirstById(serviceId);

    model.addAttribute("service", service);

    System.out.println("teste: " + serviceId);

    return "productdetail";
}

尝试一下并给出答复是否有效

如何使用Thymeleaf通过“ ID”选择列表项并直接转到另一个详细信息页面？

1 个答案: