如何将 LocalDateTime 提供给 jpa/hibernate 查询？答案

【问题标题】：How to supply LocalDateTime to a jpa/hibernate query?如何将 LocalDateTime 提供给 jpa/hibernate 查询？
【发布时间】：2020-06-04 01:35:45
【问题描述】：

我正在我的@RepositoryRestResource 中构建一个查询

查询如下所示：

@Query("Select DISTINCT comp from InsuranceCompany comp " +
            "LEFT JOIN comp.orders ord " +
            "wHERE ord.invoiced = false " +
            "and (:date is null or :date >= ord.completionTime)"
    )
public Page<InsuranceCompany> method(LocalDateTime date, Pageable pageable);

但它会引发以下异常

Failed to convert from type [java.lang.String] to type [java.time.LocalDateTime] for value '2020-02-14T15:50:24'

当我调用终点时：

GET /method?date=2020-02-14T15:50:24

【问题讨论】：

标签： postgresql hibernate spring-boot jpa spring-data-rest

【解决方案1】：

Spring 默认无法将 REST 参数转换为 LocalDateTime。您需要提供有关日期格式的信息，在参数级别使用 @DateTimeFormat 注释，或使用 DateTimeFormatterRegistrar 全局提供。

这篇文章解释了两种选择：https://www.baeldung.com/spring-date-parameters

【讨论】：

【解决方案2】：

用 @DateTimeFormat 标记它，让 Spring 正确转换它：

public Page<InsuranceCompany> method(@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime date, 
                                     Pageable pageable);

【讨论】：

【解决方案3】：

选项 1：为所有 Spring Boot App REST Endpoints 全局设置日期/时间格式

您可以全局配置 spring 以对您的 REST 端点使用特定的日期/日期时间格式。建议您使用默认的 Jackson 来处理 JSON 映射，您可以创建一个配置类，如下所示在其中设置格式：

@Configuration
public class DateTimeSerializationConfiguration implements Jackson2ObjectMapperBuilderCustomizer {

    private static final DateTimeFormatter DATE_FORMATTER = ISO_LOCAL_DATE;
    private static final DateTimeFormatter DATE_TIME_FORMATTER = ISO_DATE_TIME;
    private static final DateTimeFormatter TIME_FORMATTER = ofPattern("HH:mm");

    @Bean
    public Formatter<LocalDate> localDateFormatter() {
        return new Formatter<LocalDate>() {
            @Override
            public LocalDate parse(String text, Locale locale) {
                return LocalDate.parse(text, DATE_FORMATTER);
            }

            @Override
            public String print(LocalDate object, Locale locale) {
                return DATE_FORMATTER.format(object);
            }
        };
    }

    @Bean
    public Formatter<LocalDateTime> localDateTimeFormatter() {
        return new Formatter<LocalDateTime>() {
            @Override
            public LocalDateTime parse(String text, Locale locale) {
                return LocalDateTime.parse(text, DATE_TIME_FORMATTER);
            }

            @Override
            public String print(LocalDateTime object, Locale locale) {
                return DATE_TIME_FORMATTER.format(object);
            }
        };
    }

    @Bean
    public Formatter<LocalTime> localTimeFormatter() {
        return new Formatter<LocalTime>() {
            @Override
            public LocalTime parse(String text, Locale locale) {
                return LocalTime.parse(text, TIME_FORMATTER);
            }

            @Override
            public String print(LocalTime object, Locale locale) {
                return TIME_FORMATTER.format(object);
            }
        };
    }

    @Override
    public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
        jacksonObjectMapperBuilder.serializers(
            new LocalDateSerializer(DATE_FORMATTER),
            new LocalDateTimeSerializer(DATE_TIME_FORMATTER),
            new LocalTimeSerializer(TIME_FORMATTER));
        jacksonObjectMapperBuilder.deserializers(
            new LocalDateDeserializer(DATE_FORMATTER),
            new LocalDateTimeDeserializer(DATE_TIME_FORMATTER),
            new LocalTimeDeserializer(TIME_FORMATTER));
    }

}

然后，您可以像这样创建控制器方法：

@RestController
public class BookingController {

    private final YourService yourService;

    @Autowired
    public BookingController(YourService yourService) {
        this.yourService = yourService;
    }

    @GetMapping("/your/api/endpoint")
    public YourObject yourControllerMethod(@RequestParam LocalDate date, Pageable pageable) {
        return yourService.yourServiceMethod(date, pageable);
    }

    // Or: with LocalDateTime

    @GetMapping("/your/api/endpoint")
    public YourObject yourControllerMethod(@RequestParam LocalDateTime dateTime, Pageable pageable) {
        return yourService.yourServiceMethod(dateTime, pageable);
    }
}

选项 2：分别为每个 REST Endpoint 设置日期/时间格式

如果您希望单独为每个端点设置格式，则必须使用 @DateTimeFormat 注释请求参数并指定预期格式。下面的示例显示了有关如何完成此操作的不同示例：

@RestController
public class BookingController {

    private final YourService yourService;

    @Autowired
    public BookingController(YourService yourService) {
        this.yourService = yourService;
    }

    @GetMapping("/your/api/endpoint")
    public YourObject yourControllerMethod(@RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate date, Pageable pageable) {
        return yourService.yourServiceMethod(date, pageable);
    }

    // Or: with LocalDateTime

    @GetMapping("/your/api/endpoint")
    public YourObject yourControllerMethod(@RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime dateTime, Pageable pageable) {
        return yourService.yourServiceMethod(dateTime, pageable);
    }

    // Or: with your custom pattern

    @GetMapping("/your/api/endpoint")
    public YourObject yourControllerMethod(@RequestParam @DateTimeFormat(pattern = "dd.MM.yyyy") LocalDate date, Pageable pageable) {
        return yourService.yourServiceMethod(date, pageable);
    }
}

【讨论】：