Spring Data Sample Application

tutorial

Discover how to program interactions with Spring Data and Couchbase via the Data, Query, and Search services.

Quick Start

Fetch the Couchbase Java SDK travel-sample Application REST Backend from github:

git clone https://github.com/couchbaselabs/try-cb-spring.git
cd try-cb-spring

With Docker installed, you should now be able to run a bare-bones copy of Couchbase Server, load the travel-sample, add indexes, install the sample-application and its frontend, all by running a single command:

docker-compose --profile local up

Running the code against your own development Couchbase server.

For Couchbase Server 7.6, make sure that you have at least one node each of data; query; index; and search. For a development box, mixing more than one of these on a single node (given enough memory resources) is perfectly acceptable.

If you have yet to install Couchbase Server in your development environment start here.

Then load up the Travel Sample Bucket, using either the Web interface or the command line. You will also need to create a Search Index — Query indexes are taken care of by the Sample Bucket.

See the README at https://github.com/couchbaselabs/try-cb-spring for full details of how to run and tweak the Java SDK travel-sample app.

Using the Sample App

Give yourself a username and password and click Register.

You can now try out searching for flights, booking flights, and searching for hotels. You can see which Couchbase SDK operations are being executed by clicking the red bar at the bottom of the screen:

Sample App Backend

The backend code shows Couchbase Java SDK in action with Query and Search, but also how to plug together all of the elements and build an application with Couchbase Server, the Java SDK and Spring Data. Look at TenantUser.java to see some of the pieces necessary in most applications, such as the TenantUser @Service:

@Service
public class TenantUser {

  private final TokenService jwtService;
  private final UserRepository userRepository;
  private final BookingRepository bookingRepository;

  public TenantUser(TokenService tokenService, UserRepository userRepository, BookingRepository bookingRepository) {
    this.jwtService = tokenService;
    this.userRepository = userRepository;
    this.bookingRepository = bookingRepository;
  }

You may have noticed that we make use of Spring Data Couchbase repositories in the TenantUser class. You can see an example of how a repository is defined in UserRepository.java:

@Repository("userRepository")
@Collection("users")
@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
public interface UserRepository extends CouchbaseRepository<User, String>, DynamicProxyable<UserRepository> {

}

Using the Spring Data Couchbase repository allows us to reduce boilerplate in our code and add a layer of abstraction to our cluster interactions.

Creating a user shows the typical security concerns, with salted password hashes, as well as the advantages of using Spring Data Couchbase to save the username into the database using the userRepository we mentioned previously:

public Result<Map<String, Object>> createLogin(final String tenant, final String username, final String password,
		DurabilityLevel expiry) {
	UserRepository userRepository = this.userRepository.withScope(tenant);
	String passHash = BCrypt.hashpw(password, BCrypt.gensalt());
	User user = new User(username, passHash);
	UpsertOptions options = UpsertOptions.upsertOptions();
	if (expiry.ordinal() > 0) {
		options.durability(expiry);
	}
	String queryType = String.format("KV insert - scoped to %s.users: document %s", tenant, username);
	try {
		userRepository.withOptions(options).save(user);
		Map<String, Object> data = JsonObject.create().put("token", jwtService.buildToken(username)).toMap();
		return Result.of(data, queryType);
	} catch (Exception e) {
		throw new AuthenticationServiceException("There was an error creating account");
	}
}

Here, the flights array, containing the flight IDs, is converted to actual objects:

List<Map<String, Object>> results = new ArrayList<Map<String, Object>>();
    for (String flightId : flights) {
      Optional<Booking> res;
      try {
        res = bookingRepository.findById(flightId);
      } catch (DocumentNotFoundException ex) {
        throw new RuntimeException("Unable to retrieve flight id " + flightId);
      }
      Map<String, Object> flight = res.get().toMap();
      results.add(flight);
    }

    String queryType = String.format("KV get - scoped to %s.user: for %d bookings in document %s", tenant,
        results.size(), username);
    return Result.of(results, queryType);
  }

Data Model

See the Travel App Data Model reference page for more information about the sample data set used.