近段時間需要優(yōu)化原有的http調用，原有的http調用是直接使用HttpClient進行調用，沒有交給spring去管理，也沒有清理過期鏈接的線程，這里記錄下使用springboot如何配置HttpClient。下面直接放代碼。

①httpclient配置類，在其中可以配置http連接池最大鏈接數(shù)，并發(fā)數(shù)，超時時間，代理等。

import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class HttpClientConfig {
    private static final Logger logger = LoggerFactory.getLogger(HttpClientConfig.class);

    @Value("${http.maxTotal}")
    private Integer maxTotal;

    @Value("${http.defaultMaxPerRoute}")
    private Integer defaultMaxPerRoute;

    @Value("${http.connectTimeout}")
    private Integer connectTimeout;

    @Value("${http.connectionRequestTimeout}")
    private Integer connectionRequestTimeout;

    @Value("${http.socketTimeout}")
    private Integer socketTimeout;

    /**
     * 首先實例化一個連接池管理器，設置最大連接數(shù)、并發(fā)連接數(shù)
     *
     * @return
     */
    @Bean(name = "httpClientConnectionManager")
    public PoolingHttpClientConnectionManager getHttpClientConnectionManager() {
        PoolingHttpClientConnectionManager httpClientConnectionManager = new PoolingHttpClientConnectionManager();
        //最大連接數(shù)
        httpClientConnectionManager.setMaxTotal(maxTotal);
        //并發(fā)數(shù)
        httpClientConnectionManager.setDefaultMaxPerRoute(defaultMaxPerRoute);
        return httpClientConnectionManager;
    }

    /**
     * 實例化連接池，設置連接池管理器。
     * 這里需要以參數(shù)形式注入上面實例化的連接池管理器
     *
     * @param httpClientConnectionManager
     * @return
     */
    @Bean(name = "httpClientBuilder")
    public HttpClientBuilder getHttpClientBuilder(@Qualifier("httpClientConnectionManager") PoolingHttpClientConnectionManager httpClientConnectionManager) {

        //HttpClientBuilder中的構造方法被protected修飾，所以這里不能直接使用new來實例化一個HttpClientBuilder，可以使用HttpClientBuilder提供的靜態(tài)方法create()來獲取HttpClientBuilder對象
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();

        httpClientBuilder.setConnectionManager(httpClientConnectionManager);

        return httpClientBuilder;
    }

    /**
     * 注入連接池，用于獲取httpClient
     *
     * @param httpClientBuilder
     * @return
     */
    @Bean(name = "httpClient")
    public CloseableHttpClient getCloseableHttpClient(@Qualifier("httpClientBuilder") HttpClientBuilder httpClientBuilder) {
        return httpClientBuilder.build();
    }

    /**
     * Builder是RequestConfig的一個內部類
     * 通過RequestConfig的custom方法來獲取到一個Builder對象
     * 設置builder的連接信息
     * 這里還可以設置proxy，cookieSpec等屬性。有需要的話可以在此設置
     *
     * @return
     */
    @Bean(name = "builder")
    public RequestConfig.Builder getBuilder() {
        RequestConfig.Builder builder = RequestConfig.custom();
        return builder.setConnectTimeout(connectTimeout)
                .setConnectionRequestTimeout(connectionRequestTimeout)
                .setSocketTimeout(socketTimeout);
    }

    /**
     * 使用builder構建一個RequestConfig對象
     *
     * @param builder
     * @return
     */
    @Bean
    public RequestConfig getRequestConfig(@Qualifier("builder") RequestConfig.Builder builder) {
        return builder.build();
    }
}

②清理失效的http鏈接

@Component
public class IdleConnectionEvictor extends Thread {

    @Autowired
    private HttpClientConnectionManager httpClientConnectionManager;

    private volatile boolean shutdown;

    public IdleConnectionEvictor() {
        super();
        super.start();
    }

    @Override
    public void run() {
        try {
            while (!shutdown) {
                synchronized (this) {
                    wait(5000);
                    // 關閉失效的連接
                    httpClientConnectionManager.closeExpiredConnections();

                    httpClientConnectionManager.closeIdleConnections(30L, TimeUnit.SECONDS);
                }
            }
        } catch (InterruptedException ex) {
            // 結束
        }
    }

    //關閉清理無效連接的線程
    public void shutdown() {
        shutdown = true;
        synchronized (this) {
            notifyAll();
        }
    }
}

③進行調用，這里暫時提供get請求，post請求可以自己封裝

@Service
public class HttpClientService {
    private static final Logger logger = LoggerFactory.getLogger(HttpClientService.class);

    @Autowired
    private CloseableHttpClient httpClient;
    @Autowired
    private RequestConfig requestConfig;

    /**
     * get請求
     *
     * @return
     */
    public String doGet(String url, String charset) {
        CloseableHttpResponse response = null;
        try {
            //發(fā)送get請求
            HttpGet request = new HttpGet(url);
            request.setConfig(requestConfig);
            response = httpClient.execute(request);

            /**請求發(fā)送成功，并得到響應**/
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                /**讀取服務器返回過來的json字符串數(shù)據(jù)**/
                String strResult = EntityUtils.toString(response.getEntity());
                strResult = new String(strResult.getBytes(charset), "utf-8");
                return strResult;
            }
        } catch (IOException e) {
            logger.error("http調用出錯:{}",e.getMessage())
        } finally {
            try {
                if (response != null){
                    response.close();
                }
            }catch (IOException e){
                logger.error("關閉鏈接出錯:{}",e.getMessage());
            }
        }
        return null;
    }
}

④配置文件

#http配置服務
#最大連接數(shù)
http.maxTotal = 300
#并發(fā)數(shù)
http.defaultMaxPerRoute = 300
#創(chuàng)建連接的最長時間
http.connectTimeout=3000
#從連接池中獲取到連接的最長時間
http.connectionRequestTimeout=1000
#數(shù)據(jù)傳輸?shù)淖铋L時間
http.socketTimeout=3000