init 方法调用失败；嵌套异常是 org.hibernate.AnnotationException：没有为实体指定标识符

Question

我刚开始学习Spring。当我尝试在 Action book 的 Spring 中编写 taco-cloud 应用程序时，出现 "No identifier specified for entity" 错误。在第 3 章中，我尝试使用 H2 数据库学习 JPA。

我的订单型号：

package com.example.tacocloud.models;

import lombok.Data;

import javax.persistence.*;
import javax.validation.constraints.NotBlank;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

@Data
@Entity
@Table(name = "Taco_Order")
public class Order implements Serializable {

    ...

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private Long id;
    private Date placedAt;

    @ManyToMany(targetEntity=Taco.class)
    private List<Taco> tacos = new ArrayList<>();

    public void addDesign(Taco design) {
        this.tacos.add(design);
    }

    @PrePersist
    void placedAt() {
        this.placedAt = new Date();
    }

}

我的 Ingredient.class 看起来像这样：

package com.example.tacocloud.models;

import lombok.AccessLevel;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.RequiredArgsConstructor;

import javax.persistence.Embeddable;
import javax.persistence.Entity;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Data
@RequiredArgsConstructor
@NoArgsConstructor(access= AccessLevel.PRIVATE, force=true)
@Entity // if I change it to Embedded I get unmapped ManyToMany error in my Ingredient class.

public class Ingredient {
    private final String id;
    private final String name;
    private final Type type;

    public static enum Type{
        WRAP, PROTEIN, VEGGIES, CHEESE, SAUCE
    }
}

和我的炸玉米饼 class:

package com.example.tacocloud.models;

import lombok.Data;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.Date;
import java.util.List;

@Data
@Entity
public class Taco {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private Date createdAt;

    @NotNull
    @Size(min=5, message="Name must be at least 5 characters long")
    private  String name;
    @ManyToMany(targetEntity=Ingredient.class)
    @Size(min=1, message="You must choose at least 1 ingredient")
    private List<String> ingredients;

    @PrePersist
    void createdAt() {
        this.createdAt = new Date();
    }
}

和我的 sql 个文件：

delete from Taco_Order_Tacos;
delete from Taco_Ingredients;
delete from Taco;
delete from Taco_Order;
delete from Ingredient;
insert into Ingredient (id, name, type)
                values ('FLTO', 'Flour Tortilla', 'WRAP');
insert into Ingredient (id, name, type)
                values ('COTO', 'Corn Tortilla', 'WRAP');
insert into Ingredient (id, name, type)
                values ('GRBF', 'Ground Beef', 'PROTEIN');
insert into Ingredient (id, name, type)
                values ('CARN', 'Carnitas', 'PROTEIN');
insert into Ingredient (id, name, type)
                values ('TMTO', 'Diced Tomatoes', 'VEGGIES');
insert into Ingredient (id, name, type)
                values ('LETC', 'Lettuce', 'VEGGIES');
insert into Ingredient (id, name, type)
                values ('CHED', 'Cheddar', 'CHEESE');
insert into Ingredient (id, name, type)
                values ('JACK', 'Monterrey Jack', 'CHEESE');
insert into Ingredient (id, name, type)
                values ('SLSA', 'Salsa', 'SAUCE');
insert into Ingredient (id, name, type)
                values ('SRCR', 'Sour Cream', 'SAUCE');

schema.sql:

create table if not exists Ingredient (
  id varchar(4) not null,
  name varchar(25) not null,
  type varchar(10) not null
);
create table if not exists Taco (
  id identity,
  name varchar(50) not null,
  createdAt timestamp not null
);
create table if not exists Taco_Ingredients (
  taco bigint not null,
  ingredient varchar(4) not null
);
alter table Taco_Ingredients
    add foreign key (taco) references Taco(id);
alter table Taco_Ingredients
    add foreign key (ingredient) references Ingredient(id);
create table if not exists Taco_Order (
  id identity,
    deliveryName varchar(50) not null,
    deliveryStreet varchar(50) not null,
    deliveryCity varchar(50) not null,
    deliveryState varchar(2) not null,
    deliveryZip varchar(10) not null,
    ccNumber varchar(16) not null,
    ccExpiration varchar(5) not null,
    ccCVV varchar(3) not null,
    placedAt timestamp not null
);
create table if not exists Taco_Order_Tacos (
  tacoOrder bigint not null,
  taco bigint not null
);
alter table Taco_Order_Tacos
    add foreign key (tacoOrder) references Taco_Order(id);
alter table Taco_Order_Tacos
    add foreign key (taco) references Taco(id);

顺便说一下我的 application.properties:

spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driver-class-name = org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

谢谢。

Answer 1

您的 class Ingredient 没有 @Id 字段而且它是一个 class 不可变对象，不适合序列化 class - 你必须像其他 class 一样具有默认构造函数。删除 @NoArgsConstructor(access= AccessLevel.PRIVATE, force=true) 这很奇怪并且会混淆你的框架

init 方法调用失败；嵌套异常是 org.hibernate.AnnotationException：没有为实体指定标识符

Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity

java

spring

hibernate

jpa

h2