Spring Data Repository Autowiring troubles - spring

Question

Im having trouble autowiring my CrudRespository in my Controller (I am using Spring boot).
Here are my Controller,Entity & Respository implementations
Repository:
package com.nbha.micro.ratingService;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
public interface RaterDORepository extends CrudRepository<RaterDO, Long> {
public RaterDO findByRaterName();
}
Entity:
#Entity
public class RaterDO {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long raterId;
public RaterDO(){}
public RaterDO(String n) {
this.raterName = n;
}
public Long getRaterId() {
return raterId;
}
public void setRaterId(Long raterId) {
this.raterId = raterId;
}
public String getRaterName() {
return raterName;
}
public void setRaterName(String raterName) {
this.raterName = raterName;
}
private String raterName;
}
Controller:
#RestController
#RequestMapping("/raters")
public class RaterController {
#Autowired
private RaterDORepository raterDORepository;
#RequestMapping("/add")
public String addRater(#RequestParam("name") String name) {
RaterDO raterDO = new RaterDO(name);
raterDORepository.save(raterDO);
return "Rater:" + name +" saved.";
}
#RequestMapping("/allRaters")
public String getAllRaters() {
StringBuilder sb = new StringBuilder();
sb.append("|");
Iterable<RaterDO> raters = raterDORepository.findAll();
for(RaterDO rater : raters) {
sb.append(rater.getRaterName());
sb.append("|");
}
return sb.toString();
}
}
Starter class:
#EnableBinding(ConsumerChannels.class)
#ComponentScan(basePackages={"com.nbha.micro.ratingService"})
#EntityScan(basePackages={"com.nbha.micro.ratingService"})
#EnableJpaRepositories(basePackages={"com.nbha.micro.ratingService"})
#SpringBootApplication
#EnableEurekaClient
#RestController
#RequestMapping("/ratings")
public class RatingApp
{
public static void main( String[] args )
{
System.out.println( "Invoking Rating Service.." );
SpringApplication.run(RatingApp.class, args);
}
#StreamListener(ConsumerChannels.PRODUCER)
public void receiveRater(final Rater rater) {
if(rater != null) {
System.out.println("Rating received in the rating-service:" + rater.getName());
}
}
private List<Rating> ratingList = Arrays.asList(
new Rating("R101","101",5),
new Rating("R102","102",2),
new Rating("R103","101",4),
new Rating("R104","101",1)
);
#GetMapping("/all")
public List<Rating> findAllRatings() {
return this.ratingList;
}
#GetMapping("/rating-agency")
public String whichRatingAgency() {
return "Moody's";
}
#GetMapping("")
public List<Rating> findRatingsByBookId(#RequestParam String bookId) {
Rating r;
List<Rating> rList = new ArrayList<Rating>();
ListIterator iter = this.ratingList.listIterator();
while(iter.hasNext()) {
r = (Rating)iter.next();
if(r.getBookId().equals(bookId)) {
rList.add(r);
}
}
return rList;
}
}
interface ConsumerChannels {
String PRODUCER = "producer";
#Input
SubscribableChannel producer();
}
I placed all these classes in the same package (in a desparate bid to make it work)
I keep getting the following error on application startup (fails to startup).The interesting thing is that a similar setup works in another instance without using #ComponentScan #EntityScan #EnableJpaRepository annotations :)
Application startup failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'raterController': Unsatisfied dependency expressed through field 'raterDORepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'raterDORepository': Invocation of init method failed; nested exception is java.util.NoSuchElementException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
....
Caused by: org.springframework.beans.factory.BeanCreationException:Error creating bean with name 'raterDORepository': Invocation of init method failed; nested exception is java.util.NoSuchElementException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans- 4.3.11.RELEASE.jar:4.3.11.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
....
Caused by: java.util.NoSuchElementException: null
at java.util.ArrayList$Itr.next(ArrayList.java:860) ~[na:1.8.0_151]
at org.springframework.data.jpa.repository.query.ParameterMetadataProvider.next(ParameterMetadataProvider.java:122) ~[spring-data-jpa-1.11.7.RELEASE.jar:na]
at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.build(JpaQueryCreator.java:302) ~[spring-data-jpa-1.11.7.RELEASE.jar:na]
at org.springframework.data.jpa.repository.query.JpaQueryCreator.toPredicate(JpaQueryCreator.java:208) ~[spring-data-jpa-1.11.7.RELEASE.jar:na]
....
Any clues will be appreciated. Here are my dependencies from pom.xml:
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.7.RELEASE</version>
</parent>
<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>com.h2database</groupId>
<artifactId>h2</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-stream-kafka</artifactId>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies`enter code here`</artifactId>
<version>Brixton.SR5</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>

Answer 1

public RaterDO findByRaterName(); needs a parameter, something like public RaterDO findByRaterName(String name).
Construction of the repository fails because the missing parameter prevents Spring Data to construct a proper method.