mvn -U archetype:generate -DinteractiveMode=false \
    -DarchetypeGroupId=io.helidon.archetypes \
    -DarchetypeArtifactId=helidon-quickstart-se \
    -DarchetypeVersion=4.4.1 \
    -DgroupId=io.helidon.examples \
    -DartifactId=helidon-quickstart-se \
    -Dpackage=io.helidon.examples.quickstart.se

cd helidon-quickstart-se

<dependencies>
    <!-- ... -->
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient</artifactId> 
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-jdbc</artifactId> 
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-hikari</artifactId> 
    </dependency>
    <dependency>
        <groupId>io.helidon.integrations.db</groupId>
        <artifactId>h2</artifactId> 
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-jdk14</artifactId>
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-health</artifactId> 
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-metrics</artifactId> 
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-metrics-hikari</artifactId>
    </dependency>
    <dependency>
        <groupId>io.helidon.dbclient</groupId>
        <artifactId>helidon-dbclient-jsonp</artifactId> 
    </dependency>
    <!-- ... -->
</dependencies>

db:
  source: jdbc 
  connection: 
    url: "jdbc:h2:tcp://localhost:9092/~/test"
    username: "sa"
    password:
  statements: 
    health-check: "SELECT 0"
    create-table: "CREATE TABLE IF NOT EXISTS LIBRARY (NAME VARCHAR NOT NULL, INFO VARCHAR NOT NULL)"
    insert-book: "INSERT INTO LIBRARY (NAME, INFO) VALUES (:name, :info)"
    select-book: "SELECT INFO FROM LIBRARY WHERE NAME = ?"
    delete-book: "DELETE FROM LIBRARY WHERE NAME = ?"
  health-check:
    type: "query"
    statementName: "health-check"
  services:
    metrics:
      - type: COUNTER 
        statement-names: [ "select-book" ]

db:
  connection:
    url: "jdbc:h2:mem:test" 

public static void main(String[] args) {

    // load logging configuration
    LogConfig.configureRuntime();

    Config config = Config.global();

    DbClient dbClient = DbClient.create(config.get("db")); 
    Contexts.globalContext().register(dbClient); 

    HealthObserver healthObserver = HealthObserver.builder()
            .useSystemServices(false)
            .details(true)
            .addCheck(DbClientHealthCheck.create(dbClient, config.get("db.health-check"))) 
            .build();

    ObserveFeature observe = ObserveFeature.builder()
            .config(config.get("server.features.observe"))
            .addObserver(healthObserver) 
            .build();

    WebServer server = WebServer.builder()
            .config(config.get("server"))
            .addFeature(observe) 
            .routing(Main::routing)
            .build()
            .start();

    System.out.println("WEB server is up! http://localhost:" + server.port() + "/simple-greet");
}

public class LibraryService implements HttpService {

    private final DbClient dbClient;    

    LibraryService() {
        dbClient = Contexts.globalContext()
                .get(DbClient.class)
                .orElseGet(this::newDbClient); 
        dbClient.execute()
                .namedDml("create-table"); 
    }

    private DbClient newDbClient() {
        return DbClient.create(Config.global().get("db"));
    }

    @Override
    public void routing(HttpRules rules) {
        // TODO
    }
}

@Override
public void routing(HttpRules rules) {
    rules
            .get("/{name}", this::getBook)      
            .put("/{name}", this::addBook)      
            .delete("/{name}", this::deleteBook)   
            .get("/json/{name}", this::getJsonBook); 
}

private void getBook(ServerRequest request,
                     ServerResponse response) {

    String bookName = request.path()
            .pathParameters()
            .get("name"); 

    String bookInfo = dbClient.execute()
            .namedGet("select-book", bookName)   
            .map(row -> row.column("INFO").asString().get())
            .orElseThrow(() -> new NotFoundException(
                    "Book not found: " + bookName)); 
    response.send(bookInfo); 
}

private void getJsonBook(ServerRequest request,
                         ServerResponse response) {

    String bookName = request.path()
            .pathParameters()
            .get("name");

    JsonObject bookJson = dbClient.execute()
            .namedGet("select-book", bookName)
            .map(row -> row.as(JsonObject.class))
            .orElseThrow(() -> new NotFoundException(
                    "Book not found: " + bookName));
    response.send(bookJson);
}

private void addBook(ServerRequest request,
                     ServerResponse response) {

    String bookName = request.path()
            .pathParameters()
            .get("name");

    String newValue = request.content().as(String.class);
    dbClient.execute()
            .createNamedInsert("insert-book")
            .addParam("name", bookName) 
            .addParam("info", newValue)
            .execute();
    response.status(Status.CREATED_201).send(); 
}

private void deleteBook(ServerRequest request,
                        ServerResponse response) {

    String bookName = request.path()
            .pathParameters()
            .get("name");

    dbClient.execute().namedDelete("delete-book", bookName); 
    response.status(Status.NO_CONTENT_204).send(); 
}

static void routing(HttpRouting.Builder routing) {
    routing
            .register("/greet", new GreetService())
            .register("/library", new LibraryService()) 
            .get("/simple-greet", (req, res) -> res.send("Hello World!"));
}