Spring Boot REST API MySQL项目-内部服务器错误，状态500

Question

编辑：

发现问题。。。

我在MySQL数据库中为表“Bookings”创建了一个Bookings类（模型类），该类中的所有数据成员都是根据数据库表设置的。

当我试图查找“booking_name”的所有预订时，出现了问题，下面分别是BookingsRepository和bookings类，

package com.example.demo.bookings;

import org.springframework.data.jpa.repository.JpaRepository;

public interface BookingsRepository extends JpaRepository<Bookings, Integer>{

    Iterable<Bookings> findAllByBooking_Name(String booking_name);

}

package com.example.demo.bookings;

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

@Entity
public class Bookings {
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    int booking_id;
    String booking_name;
    int booking_pid;
    int passengers;
    double cost;
    
    public Bookings() {
        
    }
    
    public Bookings(int booking_id, String booking_name, int booking_pid, int passengers, double cost) {
        super();
        this.booking_id = booking_id;
        this.booking_name = booking_name;
        this.booking_pid = booking_pid;
        this.passengers = passengers;
        this.cost = cost;
    }

    public int getBooking_id() {
        return booking_id;
    }

    public void setBooking_id(int booking_id) {
        this.booking_id = booking_id;
    }

    public String getBooking_name() {
        return booking_name;
    }

    public void setBooking_name(String booking_name) {
        this.booking_name = booking_name;
    }

    public int getBooking_pid() {
        return booking_pid;
    }

    public void setBooking_pid(int booking_pid) {
        this.booking_pid = booking_pid;
    }

    public int getPassengers() {
        return passengers;
    }

    public void setPassengers(int passengers) {
        this.passengers = passengers;
    }

    public double getCost() {
        return cost;
    }

    public void setCost(double cost) {
        this.cost = cost;
    }
    
}

我尝试将字段“booking_name”更改为“bookingName”，但它随机化了JSON输出中字段的顺序，因此POST方法返回错误。

这是我得到的错误

Error creating bean with name 'bookingsController': Unsatisfied dependency expressed through field 'bs'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'bookingsService': Unsatisfied dependency expressed through field 'bookingRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'bookingsRepository' defined in com.example.demo.bookings.BookingsRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Invocation of init method failed; nested exception is org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.lang.Iterable com.example.demo.bookings.BookingsRepository.findAllByBooking_Name(java.lang.String); Reason: Failed to create query for method public abstract java.lang.Iterable com.example.demo.bookings.BookingsRepository.findAllByBooking_Name(java.lang.String)! No property 'booking' found for type 'Bookings'; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.lang.Iterable com.example.demo.bookings.BookingsRepository.findAllByBooking_Name(java.lang.String)! No property 'booking' found for type 'Bookings'

Answer 1

数据库中下划线分隔的字段通常映射到类中的camelCase字段。Bookings类中的字段名应为bookingName，存储库方法签名应为：

Iterable<Bookings> findAllByBookingName(String bookingName);

对于Bookings类中的所有其他字段相同。

Answer 2

在您的TopicService中，您尝试自动装配TopicsRepository，但您没有任何类型为TopicsRepository的bean。

添加以下注释：

@Repository
public interface TopicsRepository extends CrudRepository<Topics, String>{

}