如何根据我在多个下拉列表中选择的内容创建过滤器？

Question

我有大约15个下拉菜单，我想返回数据库中与下拉列表中选择的对象相同的对象。我设法用Thymeleaf和Spring在下拉列表中显示数据然后我发了一个POST请求，我收到了我选择的内容。我不知道如何使用jpa，仓库中的方法从数据库中提供对象。

控制器

@GetMapping("/filter/functionality/misramessages")
    public String filterFunctionality(Model model) {

        model.addAttribute("misraMessages", misraMessagesService.findAllMisraMessagesFromDb());
        model.addAttribute("mistraObjectSelected", new MisraMessages());

        return "functionality";
    }

    @PostMapping("/filter/functionality/misramessages")
    public String getFilterFunctionalityResult(@PathVariable(name = "buidId", required=false) Build buildId,
                                               @RequestParam(name = "fileName", required=false) String fileName,
                                               @RequestParam(name = "filePath", required=false) String filePath,
                                               @RequestParam(name = "messageNumber", required=false) String messageNumber,
                                               @RequestParam(name = "messageSeverity", required=false) String messageSeverity,
                                               @RequestParam(name = "guidelineNumber", required=false) String guidelineNumber,
                                               @RequestParam(name = "guidelineName", required=false) String guidelineName,
                                               @RequestParam(name = "guidelineType", required=false) String guidelineType,
                                               @RequestParam(name = "guidelineSeverity", required=false) String guidelineSeverity,
                                               @RequestParam(name = "requirement", required=false) String requirement,
                                               @RequestParam(name = "sourceCodeCategory", required=false) String sourceCodeCategory,
                                               @RequestParam(name = "safety", required=false) String safety,
                                               @RequestParam(name = "functionality", required=false) String functionality,
                                               @RequestParam(name = "subFunctionality", required=false) String subFunctionality,
                                               @RequestParam(name = "applicationType", required=false) String applicationType,
                                               @RequestParam(name = "supplier", required=false) String supplier,
                                               @RequestParam(name = "cmVersion", required=false) String cmVersion,
                                               @RequestParam(name = "asilLevel", required=false) String asilLevel) {


 }

下拉菜单

 <form action="#" th:action="@{/filter/result}" method="post">

        <!-- Filter Build-->
        <div class="form-group row">
            <label for="build" class="col-sm-2 col-form-label">Build</label>
            <div class="col-sm-10">
                <select class="form-control"  name="buildId" id="build">
                    <option th:value="0" text="Please Select"></option>
                    <option  th:each = "misra : ${misraMessages}"
                             th:value="${misra.buildId.buildId}"
                             th:text="${misra.buildId.buildId}">
                    </option>
                </select>
            </div>
        </div>

        <!-- Filter File Name-->
        <div class="form-group row">
            <label for="fileName" class="col-sm-2 col-form-label">File Name</label>
            <div class="col-sm-10">
                <select class="form-control"  name="fileName" id="fileName">
                    <option th:value="0" text="Please Select"></option>
                    <option  th:each = "misra : ${misraMessages}"
                             th:value="${misra.fileName}"
                             th:text="${misra.fileName}">
                    </option>
                </select>
            </div>
        </div>
           ..........
           ..........
           ..........
</form>

Answer 1

由于您的问题太广泛，我无法为您提供具体的答案，但我会尽力给您一般的想法。

首先，您需要了解JPA的工作原理。决定你想要用什么，例如。 hibernate，spring data，jdbc，mybatis等...你可以在互联网上找到很多关于如何使用JPA的教程。

首先，您需要创建一个包含所有属性的POJO类。这个POJO类是这样的东西

public class MyClass{

private String filename;
private String filePath;
...
//getters setters
}

我会将所有RequestParam组合为map。这不是必需的，但是你的代码很干净，因为你有很多RequestParam。

 @PostMapping("/filter/functionality/misramessages")
        public String getFilterFunctionalityResult(@PathVariable(name = "buidId", required=false) Build buildId,@RequestParam Map<String,String> requestParams){
// your code here
}

现在您可以将所有RequestParam值设置为POJO

Myclass myClass = new Myclass();
myclass.setFileName(requestParams.get("fileName"));
...

您必须创建@Service和@Repository类，它们将处理您与数据库交互的所有服务层逻辑和逻辑。有关spring.io的完美例子。试着在那里度过一段时间。

希望这可以帮助。