@Configuration
@PropertySource(value="classpath:/properties/httpClient.properties")
public class HttpClientConfig {
  @Value("${http.maxTotal}")
  private Integer maxTotal;            //最大連接數(shù)

  @Value("${http.defaultMaxPerRoute}")
  private Integer defaultMaxPerRoute;        //最大并發(fā)鏈接數(shù)

  @Value("${http.connectTimeout}")
  private Integer connectTimeout;          //創(chuàng)建鏈接的最大時間

  @Value("${http.connectionRequestTimeout}") 
  private Integer connectionRequestTimeout;    //鏈接獲取超時時間

  @Value("${http.socketTimeout}")
  private Integer socketTimeout;           //數(shù)據(jù)傳輸最長時間

  @Value("${http.staleConnectionCheckEnabled}")
  private boolean staleConnectionCheckEnabled;   //提交時檢查鏈接是否可用

  //定義httpClient鏈接池
  @Bean(name="httpClientConnectionManager")
  public PoolingHttpClientConnectionManager getPoolingHttpClientConnectionManager() {
    PoolingHttpClientConnectionManager manager = new PoolingHttpClientConnectionManager();
    manager.setMaxTotal(maxTotal); //設定最大鏈接數(shù)
    manager.setDefaultMaxPerRoute(defaultMaxPerRoute); //設定并發(fā)鏈接數(shù)
    return manager;
  }

  //定義HttpClient
  /**
   * 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
   @Qualifier 指定bean標簽進行注入
   */
  @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
  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
   * @return
   */
  @Bean(name = "builder")
  public RequestConfig.Builder getBuilder(){
    RequestConfig.Builder builder = RequestConfig.custom();
    return builder.setConnectTimeout(connectTimeout)
        .setConnectionRequestTimeout(connectionRequestTimeout)
        .setSocketTimeout(socketTimeout)
        .setStaleConnectionCheckEnabled(staleConnectionCheckEnabled);
  }

  /**
   * 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();
  }
}

@Component  //交給spring容器管理
public class HttpClientClose extends Thread{
  @Autowired
  private PoolingHttpClientConnectionManager manage;
  private volatile boolean shutdown;  //開關 volatitle表示多線程可變數(shù)據(jù),一個線程修改,其他線程立即修改
  
  public HttpClientClose() {
    ///System.out.println("執(zhí)行構造方法,實例化對象");
    //線程開啟啟動
    this.start();
  }
  
  
  @Override
  public void run() {
    try {
      //如果服務沒有關閉,執(zhí)行線程
      while(!shutdown) {
        synchronized (this) {
          wait(5000);      //等待5秒
          //System.out.println("線程開始執(zhí)行,關閉超時鏈接");
          //關閉超時的鏈接
          PoolStats stats = manage.getTotalStats();
          int av = stats.getAvailable();  //獲取可用的線程數(shù)量
          int pend = stats.getPending();  //獲取阻塞的線程數(shù)量
          int lea = stats.getLeased();  //獲取當前正在使用的鏈接數(shù)量
          int max = stats.getMax();
          //System.out.println("max/"+max+":  av/"+av+": pend/"+pend+":  lea/"+lea);
          manage.closeExpiredConnections();
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
      throw new RuntimeException();
    }

    super.run();
  }
  //關閉清理無效連接的線程
  @PreDestroy  //容器關閉時執(zhí)行該方法.
  public void shutdown() {
    shutdown = true;
    synchronized (this) {
      //System.out.println("關閉全部鏈接!!");
      notifyAll(); //全部從等待中喚醒.執(zhí)行關閉操作;
    }
  }

@Service
public class HttpClientService {

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

  /**
   * 通過給的url地址，獲取服務器數(shù)據(jù)
   * @param url 服務器地址
   * @param params 封裝用戶參數(shù)
   * @param charset 設定字符編碼
   * @return
   */
  public String doGet(String url, Map<String,String> params,String charset) {
    if (StringUtils.isEmpty(charset)) {
      charset = "utf-8";
    }
    //判斷是否有參數(shù)
    if (params != null) {
      url +="?";
      for (Map.Entry<String,String> entry: params.entrySet()) {
        String key = entry.getKey();
        String value = entry.getValue();
        url += key +"="+value+"&";
      }
      url = url.substring(0,url.length() - 1);
    }
    HttpGet httpGet = new HttpGet(url);
    httpGet.setConfig(requestConfig);
    String result = "";
    try {
      CloseableHttpResponse response = httpClient.execute(httpGet);
      if (response.getStatusLine().getStatusCode() == 200) {
        result = EntityUtils.toString(response.getEntity(),charset);
      }
    } catch (IOException e) {
      e.printStackTrace();
      throw new RuntimeException(e);
    }
    return result;
  }

  public String doGet(String url, Map<String,String> params) {
      return doGet(url,params,null);
  }
  public String doGet(String url) {
    return doGet(url,null,null);
  }

  public <T> T doGet(String url,Class<T> tClass,Map<String,String> map, String charSet){
    String result = doGet(url,map,charSet);
    return ObjectMapperUtil.toObject(result, tClass);
  }

}

@SpringBootTest
@RunWith(SpringRunner.class)
public class HttpClientTest {

@Autowired
private HttpClientService httpClientService;
 
@Test 
public void getTest1() {
　　　　//次url是通過nginx加hosts文件映射的，需要修改url才可以使用
    String url = "http://manage.jt.com/web/item/findItemDescById";
    Map<String,String> map = new HashMap<>();
    map.put("itemId","562379");
    String s = httpClientService.doGet(url, map);
    System.out.println(s);

  }