Springboot/Spring JPA - 具有多个 GetMapping 方法的控制器

Question

我有几个 SQL 查询从同一个 table 获取数据，只是过滤方式不同。例如：

SELECT * FROM CAR WHERE CAR_NUM <> 111    

SELECT * FROM CAR WHERE SELL_DATE BETWEEN '2020-01-01' AND '2021-12-15'  //These are DB2 TIMESTAMP fields (e.g. '2021-12-15 12:45:33')
    
SELECT * FROM CAR WHERE ...

...

...

我有大约 10 个查询，每个查询都针对 CAR 数据 table，但使用不同的 WHERE 子句以不同的方式过滤数据。

我使用 Spring JPA 实现了 CarController、CarService、CarRepository。我的控制器目前有 2 个 @GetMapping 方法，我计划添加更多 @GetMapping 方法来涵盖上面的所有 SQL 查询

@RestController
@RequestMapping("/cars") 
public class CarController {

    @GetMapping
    public List<CarResponse> getAllCars() {
      // handle 1st query above and return all cars except one with CAR_NUM=111
      List<CarResponse> cars = carRepository.getAllCarsExceptTrippleOne();
      return cars;
    }

    @GetMapping
    public List<CarResponse> getAllCarsSoldBetweenDates(@RequestParam Map<Date, Date> dateRange) {
      // handle 2nd query above and return all cars sold btw 2 dates.  My table holds DB2 TIMESTAMP fields.
      List<CarResponse> cars = carRepository.getAllCarsSoldBetweenDates(dateRange.get("startDate"), dateRange.get("endDate"));
      return cars;
    }

}

但是，我收到如下错误：

java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'carController' method com.me.carController#getAllCarsSoldBetweenDates(Map) to {GET [/cars], produces [application/json]}: There is already 'carController' bean method com.me.carController#getAllCars() mapped.

我不确定我缺少什么？

Answer 1

您为两种方法都指定了 @GetMapping()。这将两种方法与一个端点 /cars 绑定在一起。每个控制器方法都应该有与之关联的唯一映射。

@GetMapping
public List<CarResponse> getAllCars() {}

@GetMapping("/soldbetween")
public List<CarResponse> getAllCarsSoldBetweenDates(@RequestParam Map<Date, Date> dateRange) {}

Answer 2

您需要告诉 spring 当您想要获得所有汽车时要调用哪个 GET 映射，当您想要在日期之间售出汽车时要使用哪个映射。

不要理会第一个方法，将第二个方法更改为如下所示：

  @GetMapping("/sold/{startDate}/{endDate}")
  public List<CarResponse> getAllCarsSoldBetweenDates(@PathVariable Long startDate, @PathVariable Long endDate) {
      // do validation of the variables, if variables cannot be converted to dates or something
      try{
          Date startDateObj = new Date(startDate);   
          Date endDateObj = new Date(endDate);

          // handle 2nd query above and return all cars sold btw 2 dates
          List<CarResponse> cars = carRepository.getAllCarsSoldBetweenDates(startDateObj, endDateObj);
          return cars;
      }catch( Exception e ){
          // .. handle exception and return empty list?
          return Collections.emptyList();
      }      
  }

然后，要调用此方法，您可以通过调用服务器并传递参数来调用，例如：

https://<server>:<port>/cars/sold/<startDateAsLong>/<endDateAsLong>

Springboot/Spring JPA - 具有多个 GetMapping 方法的控制器

Springboot/Spring JPA - Controller with multiple GetMapping methods

spring-data-jpa

spring-boot