关于 httpclient4.5 连接池的做法

1. httpclient 4.5 连接池管理器的应用
   <small> PS:今天终天有空写一个给自己备份</small>

• API参考:在线API
• 文档参考:官方文档

public PoolingHttpClientConnectionManager getPoolCm(){
// SSLContextBuilder sslContextBuilder = new SSLContextBuilder();
// sslContextBuilder.loadTrustMaterial(null,
// new TrustSelfSignedStrategy());
// SSLConnectionSocketFactory socketFactory = new SSLConnectionSocketFactory(
// sslContextBuilder.build());
ConnectionSocketFactory plainsf = PlainConnectionSocketFactory.getSocketFactory();
LayeredConnectionSocketFactory sslsf = SSLConnectionSocketFactory.getSocketFactory();
Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", plainsf)
.register("https", sslsf)
.build();
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(registry);
// 将最大连接数增加到200
cm.setMaxTotal(200);
// 将每个路由基础的连接增加到20
cm.setDefaultMaxPerRoute(20);
//请求重试处理
return cm;
}
public CloseableHttpClient gethttpClient(){
HttpRequestRetryHandler httpRequestRetryHandler = new HttpRequestRetryHandler() {
public boolean retryRequest(IOException exception,int executionCount, HttpContext context) {
if (executionCount >= 5) {// 如果已经重试了5次，就放弃
return false;
}
if (exception instanceof NoHttpResponseException) {// 如果服务器丢掉了连接，那么就重试
return true;
}
if (exception instanceof SSLHandshakeException) {// 不要重试SSL握手异常
return false;
}
if (exception instanceof InterruptedIOException) {// 超时
return false;
}
if (exception instanceof UnknownHostException) {// 目标服务器不可达
return false;
}
if (exception instanceof ConnectTimeoutException) {// 连接被拒绝
return false;
}
if (exception instanceof SSLException) {// ssl握手异常
return false;
}

            HttpClientContext clientContext = HttpClientContext.adapt(context);
            HttpRequest request = clientContext.getRequest();
            // 如果请求是幂等的，就再次尝试
            if (!(request instanceof HttpEntityEnclosingRequest)) {                    
                return true;
            }
            return false;
        }
    };  
    
    CloseableHttpClient httpClient = HttpClients.custom()
            .setConnectionManager(cm)
            .setRetryHandler(httpRequestRetryHandler)
            .build();

return httpClient;
}
public String poolHttpsPost(String url, JSONObject json) {
CloseableHttpResponse response = null;
HttpPost post = null;
try {
// 设置代理 可省略
HttpHost proxy = new HttpHost(InetAddressStr, InetPort);
// connectTimeout设置服务器请求超时时间
// socketTimeout设置服务器响应超时时间
RequestConfig requestConfig = RequestConfig.custom()
.setProxy(proxy).setSocketTimeout(SERVER_REQUEST_TIME_OUT)
.setConnectTimeout(SERVER_RESPONSE_TIME_OUT).build();
post = new HttpPost(url);
post.setConfig(requestConfig);

        if (json != null) {
            StringEntity se = new StringEntity(json.toString(), CHAR_SET);
            se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,
                    "application/json;"));
            post.setEntity(se);
        }
        response = getHttpsClient(requestConfig).execute(post);
        int status = response.getStatusLine().getStatusCode();

        String result = null;
        if (status == 200) {
            result = EntityUtils.toString(response.getEntity(), CHAR_SET);
        }
        EntityUtils.consume(response.getEntity());
        response.close();       
        return result;
    } catch (Exception e) {
        if (e instanceof SocketTimeoutException) {
            // 服务器请求超时              
        } else if (e instanceof ConnectTimeoutException) {
            // 服务器响应超时(已经请求了)
        }
    } finally {
        post.releaseConnection();
        if (response != null) {
            try {
                EntityUtils.consume(response.getEntity());
                response.close();
            } catch (IOException e) {
                
            }
        }
    }
    // 超时或者网络不通时返回值
    return null;
}