DynamoDB NullPointerException Error on save - database

Question

Im trying to save info to DynamoDB but im currently getting the error java.lang.NullPointerException: null when using "save" on the AccountHelper class.
I followed the starter guide found on Github; https://github.com/derjust/spring-data-dynamodb
Here is my Model Class;
#DynamoDBTable(tableName = "Users")
public class User {
// #Id
private String _id;
private String bloodGroup;
private String firstName; // DO NOT change this, needs to stay firstName
private String surname;
private String email;
private String password;
private String addressline;
private String postcode;
private String latitude;
private String longitude;
public User() {}
// More Constructors, Getters & Setters
DynamoDB Config Class;
#EnableDynamoDBRepositories(includeFilters = {#ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {DynamoDBRepo.class})})
#Configuration
public class DynamoDBConfig {
#Value("${amazon.aws.accesskey}")
private String amazonAWSAccessKey;
#Value("${amazon.aws.secretkey}")
private String amazonAWSSecretKey;
public AWSCredentialsProvider amazonAWSCredentialsProvider() {
return new AWSStaticCredentialsProvider(amazonAWSCredentials());
}
#Bean
public AWSCredentials amazonAWSCredentials() {
return new BasicAWSCredentials(amazonAWSAccessKey, amazonAWSSecretKey);
}
#Primary
#Bean
public DynamoDBMapperConfig dynamoDBMapperConfig() {
return DynamoDBMapperConfig.DEFAULT;
}
#Bean
public DynamoDBMapper dynamoDBMapper(AmazonDynamoDB amazonDynamoDB, DynamoDBMapperConfig config) {
return new DynamoDBMapper(amazonDynamoDB, config);
}
#Bean
public AmazonDynamoDB amazonDynamoDB() {
return AmazonDynamoDBClientBuilder.standard().withCredentials(amazonAWSCredentialsProvider())
.withRegion(Regions.US_EAST_1).build();
}
}
Here is the method/class where i am getting the error;
#Service
public class AccountHelper {
private DynamoDBRepo dynamoDBRepo;
#Autowired
private BCryptPasswordEncoder bCryptPasswordEncoder;
public User create(String bloodGroup, String firstname, String surname, String email, String password, String addressline, String postcode) {
// Getting the error here
return dynamoDBRepo.save(new User(bloodGroup, firstname, surname, email, bCryptPasswordEncoder.encode(password), addressline, postcode));
}
// More methods below that i am not adding to keep this question to a minimum.
Here is my controller;
#Controller
#Component
public class AccountController {
#Autowired
private AccountHelper Service_functions;
#ResponseBody // Works
#PostMapping(value = "/create/{bloodGroup}/{firstname}/{surname}/{email}/{password}/{addressline}/{postcode}")
public String create( #PathVariable String bloodGroup , #PathVariable String firstname, #PathVariable String surname, #PathVariable String email, #PathVariable String password, #PathVariable String addressline, #PathVariable String postcode){
User CreateUser = Service_functions.create(bloodGroup, firstname, surname, email, password, addressline, postcode);
System.out.println("this is working");
return CreateUser.toString();
}
account properties;
spring.application.name=account-service
server.port=8020
eureka.client.service-url.defaultZone=http://localhost:8001/eureka/
amazon.aws.accesskey="" // i removed the keys
amazon.aws.secretkey=""
Any Suggestions/Help would be greatly on where i am going wrong.

Answer 1

Two things you need to fix here based on your details provided.
Add #Autowired annotation on your dynamoDBRepo variable so that it can be recognised as spring managed bean.
Based on your comment
i.e. error saying that it cannot find
com.bdonor.accountservice.Repository.DynamoDBRepo
You need to include com.bdonor.accountservice.Repository package as JPA repository package and enable jpa repository scan in your configuration.