Spring Boot @Autowired does not work with Repository

Question

I have the following mistake:

Description:

Field categoriaRepository in 
com.algaworks.algamoneyapi.resource.CategoriaResource 
required a bean named 'entityManagerFactory' that could not be found.

The injection point has the following annotations:
    - @org.springframework.beans.factory.annotation.Autowired(required=true)


Action:

Consider defining a bean named 'entityManagerFactory' in your configuration.

Code of the main project class:

package com.algaworks.algamoneyapi;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableJpaRepositories
public class AlgamoneyApiApplication {

    public static void main(String[] args) {
        SpringApplication.run(AlgamoneyApiApplication.class, args);
    }

}

Code of the Entity:

package com.algaworks.algamoneyapi.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Objects;

@Entity
@Table(name = "categoria")
public class Categoria {

    @Id
    @GeneratedValue
    private Long codigo;
    private String nome;

    public Long getCodigo() {
        return codigo;
    }

    public void setCodigo(Long codigo) {
        this.codigo = codigo;
    }

    public String getNome() {
        return nome;
    }

    public void setNome(String nome) {
        this.nome = nome;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Categoria categoria = (Categoria) o;
        return Objects.equals(codigo, categoria.codigo);
    }

    @Override
    public int hashCode() {
        return Objects.hash(codigo);
    }
}

Repository code:

package com.algaworks.algamoneyapi.repository;

import com.algaworks.algamoneyapi.model.Categoria;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;


@Repository
public interface CategoriaRepository extends JpaRepository<Categoria, Long> {
}

Controller Code:

package com.algaworks.algamoneyapi.resource;

import com.algaworks.algamoneyapi.model.Categoria;
import com.algaworks.algamoneyapi.repository.CategoriaRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/categorias")
public class CategoriaResource {

    @Autowired
    private CategoriaRepository categoriaRepository;


    @GetMapping
    public List<Categoria> listar() {
        return categoriaRepository.findAll();
    }
}

pom.xml

<?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>2.4.4</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.algaworks</groupId>
    <artifactId>algamoney-api</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>algamoney-api</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <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-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.flywaydb</groupId>
            <artifactId>flyway-core</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Project structure:

I’ve tried to:

• @EnableJpaRepositories(basePackages = "com.algaworks.algamoney.repository")
• @ComponentScan(basePackages = "com.algaworks")
• @SpringBootApplication(scanBasePackages = {"com.algaworks"})

but nothing works.

Answer 1

Apparently the repository is not being loaded in the context of Spring. To do this, the annotation is used @EnableJpaRepositories. There are some ways to do this, I believe in your case the simplest are:

• Add @EnableJpaRepositories in AlgamoneyApiApplication. By convention, Springboot will scan all classes by @Repository when starting its application, and will include it in the context of Spring;

• Your attempt: to add @EnableJpaRepositories(basePackages = "com.algaworks.algamoneyapi.repository") in AlgamoneyApiApplication. However, note the package: your repository is on com.algaworks.algamoneyapi.repository and you tried with com.algaworks.algamoney.repository. Probably why it didn’t work.