Spring Boot: At least one JPA metamodel must be present - spring

Question

Hello everyone,
I have a problem when I run my project
Caused by: java.lang.IllegalArgumentException: At least one JPA metamodel must be present!
I don't know how to fix it.I saw some same topic and They said this problem in file pom.xml. But I don't see anything wrong in my file pom.xml. So Can somebody help me
This is my Code
File pom.xml
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.webjars</groupId>
<artifactId>bootstrap</artifactId>
<version>3.3.7</version>
DemoApplication
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
#SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
Model with #Entity
package com.example.model;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name = "contact")
public class Contact implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id", nullable = false)
private int id;
#Column(name = "name", nullable = false)
private String name;
#Column(name = "email")
private String email;
#Column(name = "phone")
private String phone;
public Contact() {
super();
}
public Contact(int id, String name, String email, String phone) {
super();
this.id = id;
this.name = name;
this.email = email;
this.phone = phone;
}
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 getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
I don't know how to fix it

Answer 1

You have in your pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
But you don't have any classes with #Entity annotation defined. You need at least one of those to successfully create the Entity Manager. If not remove the above dependency.

Answer 2

Your SpringBootApplication relies in package com.example.demo; and your entity in package com.example.model; . Per Default #SpringBootApplication will try to look into its package and below. It cannot find your entities as they are in a different package, unless you specify it explicitly e.g. via
#EntityScan(basePackages = "com.example.model")