How to autowire spring-data CrudRepository

Question

A bit of Details I am having some problem while running the code given below. I am getting the following exception. When i am trying the sample code of [CrudRepository for Spring Data][1].

I have an Interface:

package com.joydeep.springboot; 

import org.springframework.data.repository.CrudRepository; 
import com.joydeep.springboot.vo.Message; 

public interface Test1 extends CrudRepository<Message, String> { }

VO Class:

package com.joydeep.springboot.vo;

import java.util.Date;    
import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Message {
    @Id
    private String id;
    private String text;
    private String author;
    private Date created;

    public Message() {
        super();
    }
    public Message(String id, String text, String author, Date created) {
        super();
        this.id = id;
        this.text = text;
        this.author = author;
        this.created = created;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getText() {
        return text;
    }
    public void setText(String text) {
        this.text = text;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    public Date getCreated() {
        return created;
    }
    public void setCreated(Date created) {
        this.created = created;
    }
    }

Controller class:

package com.joydeep.springboot; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.RestController;  

@RestController 
public class HelloCntrl { 

   @Autowired 
   Test1 test; 

   @RequestMapping("/hello")
   public String sayHi(){
      return "Hi"; 
   } 

}

Initializer class:

package com.joydeep.springboot; 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 

@SpringBootApplication 
public class CourseAPIStarter { 
   public static void main(String[] args) {
      SpringApplication.run(CourseAPIStarter.class); 
   } 
}

pom.xml:

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>io.springboot</groupId>
    <artifactId>rest-course-api</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Rest service course API</name>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.2.RELEASE</version>
    </parent>
    <properties>
        <java.version>1.8</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-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.derby</groupId>
            <artifactId>derby</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>
</project>

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'helloCntrl': Unsatisfied dependency expressed through field 'test'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.joydeep.springboot.Test1' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations {@org.springframework.beans.factory.annotation.Autowired(required=true)}

The example i am referring is from this link.

https://spring.io/guides/gs/accessing-data-jpa/

Solution

You don't need to put @Repository annotation on Test1. Put these 3 annotation on your CourseAPIStarter class your application will run like hot knife in butter.

@ComponentScan(basePackages={"com.joydeep.springboot"}) 

@EntityScan(basePackages={"com.joydeep.springboot.vo"}) 

@EnableJpaRepositories(basePackages={"com.joydeep.springboot"}) 

@ComponentScan will scan your objects, and will register them with Spring.

@EnableJpaRepositories will enable all your Spring JPA repositories to be used in your application.

@EntityScan: As you added @Entity annotation on your model object class, Spring will assume that a table will exists with name Message. So to register this class with Spring as Entity you need to use this annotation.

Comments

[Jens]

Please format your code properbly

[Joydeep]

I was looking at the link. The code says that @Repository is not needed .

[Joydeep]

Also adding the annotation do not help, I am getting the same exception still.

[amicoderozer]

Typically in a normal Spring configuration (with xml or annotations), this error means that the bean is not annotated correctly or that you haven't include in your web.xml the component-scan line. But since you use spring boot the only thing is missing here is Message class. Try post it please. The other classes seem correct to me.

[andrew0007]

Why is @SpringBootApplication not enough? Thanks

[Angshuman]

@andrew0007 When you annotate your application class with @SpringBootApplication annotation it internally enables @EnableAutoConfiguration, @ComponentScan, @ConfigurationPropertiesScan etc. Now when @EnableAutoConfiguration is included Spring ties to guess the application behavior and adds the required configuration by reading the jar dependency you have added and if it founds any datasource is added in the project it will automatically configure these annotations with the default value. That means @SpringBootApplication alone will work and for these annotations.

[Angshuman]

@SpringBootApplication