在 Spring MVC、CrudRepository、Thymeleaf 中搜索（通过文本字段和按钮）答案

【问题标题】：Search (via text field and button) in Spring MVC, CrudRepository, Thymeleaf在 Spring MVC、CrudRepository、Thymeleaf 中搜索（通过文本字段和按钮）
【发布时间】：2017-05-09 22:38:20
【问题描述】：

我想通过 CrudRepository 的方法创建一个简单的搜索按钮，并在网站上显示记录。我是初学者，所以对你来说可能看起来太琐碎了，但我还是在征求意见:)

StudentRepository.java

public interface StudentRepository extends CrudRepository<Student, Integer> {
    Iterable<Student> findBySurname(String surname);
}

StudentService.java

public interface StudentService {
    Iterable<Student> listStudentsBySurname(String surname);
}

StudentServiceImpl.java

@Service
public class StudentServiceImpl implements StudentService {
    private StudentRepository studentRepository;

    @Autowired
    public void setStudentRepository(StudentRepository studentRepository) {
        this.studentRepository = studentRepository;
    }

    @Override
    public Iterable<Student> listStudentsBySurname(String surname) {
        return studentRepository.findBySurname(surname);
    }
}

students.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head lang="en">

    <title></title>

    <!--/*/ <th:block th:include="fragments/headerincStudent :: head"></th:block> /*/-->
</head>
<body>
<div class="container">
    <!--/*/ <th:block th:include="fragments/headerStudent :: header"></th:block> /*/-->

    <h2>Search for students</h2>
    <form th:object="${student}" th:action="@{/students}" method="get">
        <input type="text" name="search" id="search" th:value="${search}"/>
        <input type="submit" value="Search"/>
        <div th:if="${not #lists.isEmpty(search)}">
            <h2>Students List</h2>
            <table class="table table-striped">
                <tr>
                    <th>Id</th>
                    <th>Name</th>
                    <th>Surname</th>
                </tr>
                <tr th:each="student: ${search}">
                    <td th:text="${student.idStudent}"><a href="/student/${student.idStudent}">idStudent</a></td>
                    <td th:text="${student.name}">name</td>
                    <td th:text="${student.surname}">surname</td>
                </tr>
            </table>
        </div>
    </form>
</div>
</body>
</html>

StudentController.java

@Controller
public class StudentController {
    private StudentService studentService;

    @Autowired
    public void setStudentService(StudentService studentService) {
        this.studentService = studentService;
    }

    @RequestMapping(value = "students/{surname}", method = RequestMethod.GET)
    public String showStudentBySurname(@PathVariable String surname, Model model) {
        model.addAttribute("search", studentService.listStudentsBySurname(surname));
        return "students";
    }
}

我设法用我的本地数据库做简单的 CRUD。我已经直接在网站上通过 findAll 方法查看了学生列表，但现在我想对带有按钮的文本字段执行此操作，但我不知道接下来要做什么。

【问题讨论】：

标签： java spring hibernate thymeleaf crud

【解决方案1】：

你需要改变它：

@RequestMapping(value = "students/{surname}", method = RequestMethod.GET)
    public String showStudentBySurname(@PathVariable String surname, Model model) {
        model.addAttribute("search", studentService.listStudentsBySurname(surname));
        return "students";
    }

到：

@RequestMapping(value = "students", method = RequestMethod.GET)
public String showStudentBySurname(@RequestParam (value = "surname", required = false) String surname, Model model) {
    model.addAttribute("search", studentService.listStudentsBySurname(surname));
    return "students";
}

因为您从表单发送参数。 @PathVariable 用于通过链接获取搜索结果（例如<a href="/students/surname">Surname </a>）

【讨论】：

谢谢，但还是不行：/ [之前（启动应用程序）][1] [之后，当我输入姓氏时，但在数据库中有这样的姓氏][ 2] [1]：i.stack.imgur.com/V8qyK.jpg [2]：i.stack.imgur.com/jMliS.jpg
只需在@RequestParam 中将 value = "surname" 更改为 value = "search"

【解决方案2】：

    @RequestMapping(value = "students", method = RequestMethod.GET)
public String showStudentBySurname(@RequestParam (value = "search", required = false) String surname, Model model) {
    model.addAttribute("search", studentService.listStudentsBySurname(search));
    return "students";
}

实际的问题是您使用不存在的名为 surname 的参数按姓氏搜索学生，同时您想使用 HTML 文件中搜索输入的名称“search”进行搜索。

【讨论】：