HttpClient(4.5.x)正確的使用姿式

時間  2019-11-13
標籤 httpclient 4.5.x 正確 使用 欄目 系統網絡 简体版
原文   原文鏈接

 

前言:

　　httpclient(4.5.x)默認是啓動鏈接池的, 其下降時耗(避免鏈接初3次握手, 以及關閉4次握手的消耗), 顯著提高高併發處理能力(大量減小time_wait), 確實扮演了重要的角色. 可是封裝httpclient, 須要瞭解很多細節, 還要根據業務合理配置參數.
　　這裏結合這段時間深刻httpclient(4.5.x)源碼分析, 結合網上的代碼案例, 以及線下測試的結果. 嘗試寫一個可用的的httpclient封裝類, 兼顧性能, 接口友好. 感謝cctv, ^_^.html

 

相關文章:

　　1. HttpClient官方sample代碼的深刻分析(鏈接池)java

 

初版本:

　　啥也不說了, 直接貼代碼了.api

public class PooledHttpClientAdaptor {

    private static final int DEFAULT_POOL_MAX_TOTAL = 200;
    private static final int DEFAULT_POOL_MAX_PER_ROUTE = 200;

    private static final int DEFAULT_CONNECT_TIMEOUT = 500;
    private static final int DEFAULT_CONNECT_REQUEST_TIMEOUT = 500;
    private static final int DEFAULT_SOCKET_TIMEOUT = 2000;

    private PoolingHttpClientConnectionManager gcm = null;
    private CloseableHttpClient httpClient = null;

    // 鏈接池的最大鏈接數
    private final int maxTotal;
    // 鏈接池按route配置的最大鏈接數
    private final int maxPerRoute;

    // tcp connect的超時時間
    private final int connectTimeout;
    // 從鏈接池獲取鏈接的超時時間
    private final int connectRequestTimeout;
    // tcp io的讀寫超時時間
    private final int socketTimeout;

    public PooledHttpClientAdaptor() {
        this(
                PooledHttpClientAdaptor.DEFAULT_POOL_MAX_TOTAL,
                PooledHttpClientAdaptor.DEFAULT_POOL_MAX_PER_ROUTE,
                PooledHttpClientAdaptor.DEFAULT_CONNECT_TIMEOUT,
                PooledHttpClientAdaptor.DEFAULT_CONNECT_REQUEST_TIMEOUT,
                PooledHttpClientAdaptor.DEFAULT_SOCKET_TIMEOUT
        );
    }

    public PooledHttpClientAdaptor(
            int maxTotal,
            int maxPerRoute,
            int connectTimeout,
            int connectRequestTimeout,
            int socketTimeout
    ) {

        this.maxTotal = maxTotal;
        this.maxPerRoute = maxPerRoute;
        this.connectTimeout = connectTimeout;
        this.connectRequestTimeout = connectRequestTimeout;
        this.socketTimeout = socketTimeout;

        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();

        gcm = new PoolingHttpClientConnectionManager(registry);
        gcm.setMaxTotal(this.maxTotal);
        gcm.setDefaultMaxPerRoute(this.maxPerRoute);

        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(this.connectTimeout)                     // 設置鏈接超時
                .setSocketTimeout(this.socketTimeout)                       // 設置讀取超時
                .setConnectionRequestTimeout(this.connectRequestTimeout)    // 設置從鏈接池獲取鏈接實例的超時
                .build();

        HttpClientBuilder httpClientBuilder = HttpClients.custom();
        httpClient = httpClientBuilder
                .setConnectionManager(gcm)
                .setDefaultRequestConfig(requestConfig)
                .build();
    }

    public String doGet(String url) {
        return this.doGet(url, Collections.EMPTY_MAP, Collections.EMPTY_MAP);
    }

    public String doGet(String url, Map<String, Object> params) {
        return this.doGet(url, Collections.EMPTY_MAP, params);
    }

    public String doGet(String url,
                        Map<String, String> headers,
                        Map<String, Object> params
    ) {

        // *) 構建GET請求頭
        String apiUrl = getUrlWithParams(url, params);
        HttpGet httpGet = new HttpGet(apiUrl);

        // *) 設置header信息
        if ( headers != null && headers.size() > 0 ) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                httpGet.addHeader(entry.getKey(), entry.getValue());
            }
        }

        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpGet);
            if (response == null || response.getStatusLine() == null) {
                return null;
            }

            int statusCode = response.getStatusLine().getStatusCode();
            if ( statusCode == HttpStatus.SC_OK ) {
                HttpEntity entityRes = response.getEntity();
                if (entityRes != null) {
                    return EntityUtils.toString(entityRes, "UTF-8");
                }
            }
            return null;
        } catch (IOException e) {
        } finally {
            if ( response != null ) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
        }
        return null;
    }


    public String doPost(String apiUrl, Map<String, Object> params) {
        return this.doPost(apiUrl, Collections.EMPTY_MAP, params);
    }

    public String doPost(String apiUrl,
                         Map<String, String> headers,
                         Map<String, Object> params
    ) {

        HttpPost httpPost = new HttpPost(apiUrl);

        // *) 配置請求headers
        if ( headers != null && headers.size() > 0 ) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                httpPost.addHeader(entry.getKey(), entry.getValue());
            }
        }

        // *) 配置請求參數
        if ( params != null && params.size() > 0 ) {
            HttpEntity entityReq = getUrlEncodedFormEntity(params);
            httpPost.setEntity(entityReq);
        }


        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpPost);
            if (response == null || response.getStatusLine() == null) {
                return null;
            }

            int statusCode = response.getStatusLine().getStatusCode();
            if ( statusCode == HttpStatus.SC_OK ) {
                HttpEntity entityRes = response.getEntity();
                if ( entityRes != null ) {
                    return EntityUtils.toString(entityRes, "UTF-8");
                }
            }
            return null;
        } catch (IOException e) {
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
        }
        return null;

    }

    private HttpEntity getUrlEncodedFormEntity(Map<String, Object> params) {
        List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
        for (Map.Entry<String, Object> entry : params.entrySet()) {
            NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
                    .getValue().toString());
            pairList.add(pair);
        }
        return new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8"));
    }

    private String getUrlWithParams(String url, Map<String, Object> params) {
        boolean first = true;
        StringBuilder sb = new StringBuilder(url);
        for (String key : params.keySet()) {
            char ch = '&';
            if (first == true) {
                ch = '?';
                first = false;
            }
            String value = params.get(key).toString();
            try {
                String sval = URLEncoder.encode(value, "UTF-8");
                sb.append(ch).append(key).append("=").append(sval);
            } catch (UnsupportedEncodingException e) {
            }
        }
        return sb.toString();
    }

}

 

存在問題&解決方案

　　這個版本基本沒啥問題, 可是當流量爲0時, 你會發現存在處於ClOSE_WAIT的鏈接. 究其緣由是, httpclient清理過時/被動關閉的socket, 是採用懶惰清理的策略. 它是在鏈接從鏈接池取出使用的時候, 檢測狀態並作相應處理. 若是沒有流量, 那這些socket將一直處於CLOSE_WAIT(半鏈接的狀態), 系統資源被浪費.
　　不過解決方案也至關的簡單, 官方的建議引入一個清理線程, 按期主動處理過時/空閒鏈接, 這樣就OK了.安全

    private class IdleConnectionMonitorThread extends Thread {

        private final HttpClientConnectionManager connMgr;
        private volatile boolean exitFlag = false;

        public IdleConnectionMonitorThread(HttpClientConnectionManager connMgr) {
            this.connMgr = connMgr;
            setDaemon(true);
        }

        @Override
        public void run() {
            while (!this.exitFlag) {
                synchronized (this) {
                    try {
                        this.wait(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                // 關閉失效的鏈接
                connMgr.closeExpiredConnections();
                // 可選的, 關閉30秒內不活動的鏈接
                connMgr.closeIdleConnections(30, TimeUnit.SECONDS);
            }
        }

        public void shutdown() {
            this.exitFlag = true;
            synchronized (this) {
                notify();
            }
        }

    }

　　

最終版本

　　直接整合貼代碼, ^_^.併發

public class PooledHttpClientAdaptor {

    private static final int DEFAULT_POOL_MAX_TOTAL = 200;
    private static final int DEFAULT_POOL_MAX_PER_ROUTE = 200;

    private static final int DEFAULT_CONNECT_TIMEOUT = 500;
    private static final int DEFAULT_CONNECT_REQUEST_TIMEOUT = 500;
    private static final int DEFAULT_SOCKET_TIMEOUT = 2000;

    private PoolingHttpClientConnectionManager gcm = null;

    private CloseableHttpClient httpClient = null;

    private IdleConnectionMonitorThread idleThread = null;

    // 鏈接池的最大鏈接數
    private final int maxTotal;
    // 鏈接池按route配置的最大鏈接數
    private final int maxPerRoute;

    // tcp connect的超時時間
    private final int connectTimeout;
    // 從鏈接池獲取鏈接的超時時間
    private final int connectRequestTimeout;
    // tcp io的讀寫超時時間
    private final int socketTimeout;

    public PooledHttpClientAdaptor() {
        this(
                PooledHttpClientAdaptor.DEFAULT_POOL_MAX_TOTAL,
                PooledHttpClientAdaptor.DEFAULT_POOL_MAX_PER_ROUTE,
                PooledHttpClientAdaptor.DEFAULT_CONNECT_TIMEOUT,
                PooledHttpClientAdaptor.DEFAULT_CONNECT_REQUEST_TIMEOUT,
                PooledHttpClientAdaptor.DEFAULT_SOCKET_TIMEOUT
        );
    }

    public PooledHttpClientAdaptor(
            int maxTotal,
            int maxPerRoute,
            int connectTimeout,
            int connectRequestTimeout,
            int socketTimeout
    ) {

        this.maxTotal = maxTotal;
        this.maxPerRoute = maxPerRoute;
        this.connectTimeout = connectTimeout;
        this.connectRequestTimeout = connectRequestTimeout;
        this.socketTimeout = socketTimeout;

        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();

        this.gcm = new PoolingHttpClientConnectionManager(registry);
        this.gcm.setMaxTotal(this.maxTotal);
        this.gcm.setDefaultMaxPerRoute(this.maxPerRoute);

        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(this.connectTimeout)                     // 設置鏈接超時
                .setSocketTimeout(this.socketTimeout)                       // 設置讀取超時
                .setConnectionRequestTimeout(this.connectRequestTimeout)    // 設置從鏈接池獲取鏈接實例的超時
                .build();

        HttpClientBuilder httpClientBuilder = HttpClients.custom();
        httpClient = httpClientBuilder
                .setConnectionManager(this.gcm)
                .setDefaultRequestConfig(requestConfig)
                .build();

        idleThread = new IdleConnectionMonitorThread(this.gcm);
        idleThread.start();

    }

    public String doGet(String url) {
        return this.doGet(url, Collections.EMPTY_MAP, Collections.EMPTY_MAP);
    }

    public String doGet(String url, Map<String, Object> params) {
        return this.doGet(url, Collections.EMPTY_MAP, params);
    }

    public String doGet(String url,
                        Map<String, String> headers,
                        Map<String, Object> params
    ) {

        // *) 構建GET請求頭
        String apiUrl = getUrlWithParams(url, params);
        HttpGet httpGet = new HttpGet(apiUrl);

        // *) 設置header信息
        if ( headers != null && headers.size() > 0 ) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                httpGet.addHeader(entry.getKey(), entry.getValue());
            }
        }

        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpGet);
            if (response == null || response.getStatusLine() == null) {
                return null;
            }

            int statusCode = response.getStatusLine().getStatusCode();
            if ( statusCode == HttpStatus.SC_OK ) {
                HttpEntity entityRes = response.getEntity();
                if (entityRes != null) {
                    return EntityUtils.toString(entityRes, "UTF-8");
                }
            }
            return null;
        } catch (IOException e) {
        } finally {
            if ( response != null ) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
        }
        return null;
    }

    public String doPost(String apiUrl, Map<String, Object> params) {
        return this.doPost(apiUrl, Collections.EMPTY_MAP, params);
    }

    public String doPost(String apiUrl,
                         Map<String, String> headers,
                         Map<String, Object> params
    ) {

        HttpPost httpPost = new HttpPost(apiUrl);

        // *) 配置請求headers
        if ( headers != null && headers.size() > 0 ) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                httpPost.addHeader(entry.getKey(), entry.getValue());
            }
        }

        // *) 配置請求參數
        if ( params != null && params.size() > 0 ) {
            HttpEntity entityReq = getUrlEncodedFormEntity(params);
            httpPost.setEntity(entityReq);
        }


        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpPost);
            if (response == null || response.getStatusLine() == null) {
                return null;
            }

            int statusCode = response.getStatusLine().getStatusCode();
            if ( statusCode == HttpStatus.SC_OK ) {
                HttpEntity entityRes = response.getEntity();
                if ( entityRes != null ) {
                    return EntityUtils.toString(entityRes, "UTF-8");
                }
            }
            return null;
        } catch (IOException e) {
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
        }
        return null;

    }

    private HttpEntity getUrlEncodedFormEntity(Map<String, Object> params) {
        List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
        for (Map.Entry<String, Object> entry : params.entrySet()) {
            NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
                    .getValue().toString());
            pairList.add(pair);
        }
        return new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8"));
    }

    private String getUrlWithParams(String url, Map<String, Object> params) {
        boolean first = true;
        StringBuilder sb = new StringBuilder(url);
        for (String key : params.keySet()) {
            char ch = '&';
            if (first == true) {
                ch = '?';
                first = false;
            }
            String value = params.get(key).toString();
            try {
                String sval = URLEncoder.encode(value, "UTF-8");
                sb.append(ch).append(key).append("=").append(sval);
            } catch (UnsupportedEncodingException e) {
            }
        }
        return sb.toString();
    }


    public void shutdown() {
        idleThread.shutdown();
    }

    // 監控有異常的連接
    private class IdleConnectionMonitorThread extends Thread {

        private final HttpClientConnectionManager connMgr;
        private volatile boolean exitFlag = false;

        public IdleConnectionMonitorThread(HttpClientConnectionManager connMgr) {
            this.connMgr = connMgr;
            setDaemon(true);
        }

        @Override
        public void run() {
            while (!this.exitFlag) {
                synchronized (this) {
                    try {
                        this.wait(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                // 關閉失效的鏈接
                connMgr.closeExpiredConnections();
                // 可選的, 關閉30秒內不活動的鏈接
                connMgr.closeIdleConnections(30, TimeUnit.SECONDS);
            }
        }

        public void shutdown() {
            this.exitFlag = true;
            synchronized (this) {
                notify();
            }
        }

    }

}

 

總結:

　　其實沒啥難道, 主要就是買個安心, 這樣寫是安全的, 是經得起線上考驗的.app

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