在使用Apache HTTPAsyncClient时，可以通过实现ResponseConsumer接口，并在其consumeContent方法中关闭连接来解决在响应之前关闭连接的问题。以下是一个示例代码：

import java.io.IOException;
import java.util.concurrent.Future;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import org.apache.http.nio.IOReactorException;
import org.apache.http.nio.client.methods.HttpAsyncMethods;
import org.apache.http.nio.protocol.HttpAsyncRequestProducer;
import org.apache.http.nio.protocol.HttpAsyncResponseConsumer;
import org.apache.http.protocol.HttpContext;

public class ApacheHttpAsyncClientExample {

    public static void main(String[] args) throws IOReactorException {
        CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault();
        try {
            httpclient.start();

            HttpGet request = new HttpGet("https://example.com");

            HttpAsyncRequestProducer producer = HttpAsyncMethods.create(request);
            HttpAsyncResponseConsumer consumer = new MyResponseConsumer();

            Future future = httpclient.execute(producer, consumer, new FutureCallback() {
                @Override
                public void completed(final HttpResponse response) {
                    System.out.println(request.getRequestLine() + "->" + response.getStatusLine());
                }

                @Override
                public void failed(final Exception ex) {
                    System.out.println(request.getRequestLine() + "->" + ex);
                }

                @Override
                public void cancelled() {
                    System.out.println(request.getRequestLine() + " cancelled");
                }
            });

            HttpResponse response = future.get();
            // 在这里处理响应

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    static class MyResponseConsumer implements HttpAsyncResponseConsumer {

        private HttpResponse response;

        @Override
        public void failed(Exception ex) {
            ex.printStackTrace();
        }

        @Override
        public void consumeResponse(HttpResponse response, HttpContext context) throws IOException {
            this.response = response;
        }

        @Override
        public void responseReceived(HttpResponse response) throws IOException {
            // 不需要处理
        }

        @Override
        public HttpResponse getResult() {
            return this.response;
        }

        @Override
        public boolean isDone() {
            return this.response != null;
        }

        @Override
        public void close() throws IOException {
            // 在这里关闭连接
            if (this.response != null) {
                this.response.getEntity().getContent().close();
            }
        }
    }
}

在上面的示例中，我们实现了自定义的ResponseConsumer类MyResponseConsumer来控制在consumeContent方法中关闭连接。在consumeContent方法中，我们检查响应是否已经接收并将其存储在response字段中。在close方法中，我们关闭连接的输入流，确保在不再需要时释放资源。

请注意，这只是一个简单的示例，实际应用中可能需要更复杂的处理逻辑。