Spring data mongodb. Generating id's error

Mongo ObjectIds don't map to a java Long type.

I see this in the documentation, under 7.6.1:

http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mongo-template.id-handling

An id property or field declared as a String in the Java class will be converted to and stored as an ObjectId if possible using a Spring Converter. Valid conversion rules are delegated to the MongoDB Java driver. If it cannot be converted to an ObjectId, then the value will be stored as a string in the database.

An id property or field declared as BigInteger in the Java class will be converted to and stored as an ObjectId using a Spring Converter.

So change id to a String or a BigInteger and remove the strategy argument.

Using @Id as a String works fine.

Make sure that your Repository extends with a String (same type as the @Id):

extends MongoRepository<MyEntity, String>

I think the problem is that you are using Entity instead of Document. Mongo dao's should use Document annotation and the repository should extend the MongoRepository interface. This would be an example using what you have. First you'll want to add the mongo dependency to your pom (I assume you are using spring boot parent, so version number will be defined there)

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

import org.springframework.data.annotation.Id; 
import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection = "ACCOUNTS")
public class Account {

    @Id
    private String id;

    ....rest of properties
}

import org.springframework.data.mongodb.repository.MongoRepository;
public interface AccountRepository extends MongoRepository<Account, String>  {
    //any extra queries needed
}