PoolingAsyncClientConnectionManager HttpAsyncClients 写一个带线程池的工具类

好的，下面是一个简单的带线程池的HttpAsyncClients工具类的实现，使用了PoolingAsyncClientConnectionManager来提高连接复用和效率：

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpUriRequest;
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.impl.nio.conn.PoolingAsyncClientConnectionManager;

public class HttpAsyncClientUtils {
    private static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 200;
    private static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 20;
    private static final int DEFAULT_SOCKET_TIMEOUT = 5000;
    private static final int DEFAULT_CONNECTION_TIMEOUT = 5000;
    private static final int DEFAULT_CONNECTION_REQUEST_TIMEOUT = 5000;
    private static final int DEFAULT_THREAD_POOL_SIZE = 10;

    private static CloseableHttpAsyncClient httpAsyncClient;

    private static ExecutorService threadPool;

    static {
        PoolingAsyncClientConnectionManager connectionManager = new PoolingAsyncClientConnectionManager();
        connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL_CONNECTIONS);
        connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_CONNECTIONS_PER_ROUTE);

        httpAsyncClient = HttpAsyncClients.custom()
                .setConnectionManager(connectionManager)
                .build();

        httpAsyncClient.start();

        threadPool = Executors.newFixedThreadPool(DEFAULT_THREAD_POOL_SIZE);
    }

    public static void execute(HttpUriRequest request, FutureCallback<HttpResponse> callback) {
        httpAsyncClient.execute(request, callback);
    }

    public static void execute(HttpUriRequest request) {
        httpAsyncClient.execute(request, null);
    }

    public static void execute(HttpUriRequest request, FutureCallback<HttpResponse> callback, long timeout, TimeUnit timeUnit) {
        httpAsyncClient.execute(request, callback);

        threadPool.submit(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(timeUnit.toMillis(timeout));
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    httpAsyncClient.close();
                }
            }
        });
    }
}

这个工具类中，我们使用了静态代码块来初始化线程池和HttpAsyncClient。我们提供了三个execute方法，其中第一个方法接受一个FutureCallback参数，用于异步接收返回结果；第二个方法是同步执行，不需要传入callback参数；第三个方法除了执行请求外，还会在指定时间后关闭HttpAsyncClient，此时线程池也会被关闭。