How to fix org.hibernate.AnnotationException: No identifier specified for entity - spring-boot

Question

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: com.javacourse.project.hibernateAndJPA.Entities.City
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1788) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:609) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.3.jar:5.3.3]
package com.javacourse.project.hibernateAndJPA.Entities;
import javax.persistence.*;
#Entity
#Table(name="city")
public class City {
#Column(name="Id")
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
#Column(name="name")
private String name;
#Column(name="countryCode")
private String countryCode;
#Column(name="district")
private String district;
#Column(name="population")
private int population;
public City(int id, String name, String countryCode, String district, int population) {
super();
this.id = id;
this.name = name;
this.countryCode = countryCode;
this.district = district;
this.population = population;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCountryCode() {
return countryCode;
}
public void setCountryCode(String countryCode) {
this.countryCode = countryCode;
}
public String getDistrict() {
return district;
}
public void setDistrict(String district) {
this.district = district;
}
public int getPopulation() {
return population;
}
public void setPopulation(int population) {
this.population = population;
}
}
Application Proporties:
spring.datasource.url=jdbc:derby://localhost:1527/sample
spring.datasource.username=user
spring.datasource.password=1234
spring.datasource.initialize=false
spring.datasource.driver-class-name=org.apache.derby.jdbc.ClientDriver
pom.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.javacourse.project</groupId>
<artifactId>hibernateAndJPA</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>hibernateAndJPA</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.derby/derbyclient -->
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derbyclient</artifactId>
<version>10.15.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derbyclient</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

Answer 1

The #Id annotation is missing
#Id
#Column(name="Id")
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
Every entity needs an ID aka primary key