AWS AsyncHandlerAdpater

AsyncHandlerAdpater.java

import com.amazonaws.AmazonWebServiceRequest;
import com.amazonaws.handlers.AsyncHandler;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBAsync;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBAsyncClientBuilder;
import com.amazonaws.services.dynamodbv2.model.DescribeTableRequest;
import com.amazonaws.services.dynamodbv2.model.DescribeTableResult;
import io.vertx.core.AsyncResult;
import io.vertx.core.Context;
import io.vertx.core.Future;
import io.vertx.core.Handler;
import io.vertx.core.Vertx;

import java.util.Objects;

/**
 * @author Thomas Segismont
 */
public class AsyncHandlerAdpater<REQUEST extends AmazonWebServiceRequest, RESULT> implements AsyncHandler<REQUEST, RESULT> {

  private final Context context;
  private final Future<RESULT> future;

  public AsyncHandlerAdpater(Handler<AsyncResult<RESULT>> handler) {
    context = Vertx.currentContext();
    Objects.requireNonNull(context);
    future = Future.<RESULT>future().setHandler(handler);
  }

  @Override
  public void onError(Exception e) {
    context.runOnContext(v -> future.fail(e));
  }

  @Override
  public void onSuccess(REQUEST request, RESULT result) {
    context.runOnContext(v -> future.complete(result));
  }
}

MyVerticle.java

import com.amazonaws.services.dynamodbv2.AmazonDynamoDBAsync;
import com.amazonaws.services.dynamodbv2.model.DescribeTableRequest;
import com.amazonaws.services.dynamodbv2.model.DescribeTableResult;
import io.vertx.core.AbstractVerticle

/**
 * @author Thomas Segismont
 */
public class MyVerticle extends AbstractVerticle {

  private final AmazonDynamoDBAsync dynamoDB;

  public MyVerticle(AmazonDynamoDBAsync dynamoDB) {
    this.dynamoDB = dynamoDB;
  }

  @Override
  public void start() throws Exception {
    vertx.createHttpServer()
      .requestHandler(req -> {
        DescribeTableRequest describeTableRequest = new DescribeTableRequest().withTableName("myTableName");
        dynamoDB.describeTableAsync(describeTableRequest, new AsyncHandlerAdpater<>(ar -> {
          if (ar.succeeded()) {
            DescribeTableResult result = ar.result();
            String tableStatus = result.getTable().getTableStatus();
            req.response().end(tableStatus);
          } else {
            ar.cause().printStackTrace();
            req.response().setStatusCode(500).end("Internal server error");
          }
        }));
      });
  }
}