HttpClient工具类

由于原本工具类中只有get和post请求方法，而工作中又需要用到put和delete请求来修改和删除数据，于是在get和post方法的基础上添加了put和delete请求方法。

其中put请求方法类似于post；delete方法类似于get。

/**
*
* 发送/获取HTTP请求的工具类
* 符合restAPI风格，分别有POST, DELETE, PUT, GET四种方法
* 分别对应增、删、改、查操作
*
*/
@Slf4j
public class HttpClientUtils {
    private static final CloseableHttpClient httpClient;
    public static final String CHARSET = "UTF-8";
    private final Logger logger = LoggerFactory.getLogger(getClass());
    static {
        RequestConfig config = RequestConfig.custom()
                .setConnectTimeout(8 * 1000)
                .setSocketTimeout(8 * 1000)
                .setConnectionRequestTimeout(8 * 1000)
                .build();

        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(200);            // 将最大连接数增加到200
        cm.setDefaultMaxPerRoute(20);   // 将每个路由基础的连接增加到20

        //请求重试处理
        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;
            }
        };

        httpClient = HttpClientBuilder.create().setDefaultRequestConfig(config)
                .setConnectionManager(cm)
                .setRetryHandler(httpRequestRetryHandler)
                .build();
    }

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

    public static <T extends Object> String doGet(String url, Map<String, T> params, Map<String, String> headers) {
        return doGet(url, params, CHARSET, headers);
    }

    public static <T extends Object> String doPost(String url, Map<String, T> params) {
        return doPost(url, params, CHARSET);
    }

    /**
     * HTTP Get 获取内容
     *
     * @param url     请求的url地址 ?之前的地址
     * @param params  请求的参数
     * @param charset 编码格式
     * @return 页面内容
     */
    public static <T extends Object> String doGet(String url, Map<String, T> params, String charset,
                                                  Map<String, String> headers) {
        if (StringUtils.isBlank(url)) {
            return null;
        }

       System.out.println("http:get:request:url: {"+url+"}, params:{"+params+"}");
        CloseableHttpResponse response = null;
        String result = null;

        HttpGet httpGet = null;
        try {
            if (params != null && !params.isEmpty()) {
                List<NameValuePair> pairs = new ArrayList<>(params.size());
                for (Map.Entry<String, T> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        pairs.add(new BasicNameValuePair(entry.getKey(), value.toString()));
                    }
                }
                url += "?" + EntityUtils.toString(new UrlEncodedFormEntity(pairs, charset));
            }
            System.out.println("url: {"+url+"}");
            httpGet = new HttpGet(url);
            // header
            if (headers != null && !headers.isEmpty()) {
                for (String key : headers.keySet()) {
                    httpGet.setHeader(key, headers.get(key));
                }
            }

            response = httpClient.execute(httpGet);

            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != 200) {
                httpGet.abort();
                throw new RuntimeException("HttpClient,error status code :" + statusCode);
            }

        } catch (Exception e) {
            if (httpGet != null) {
                httpGet.abort();
            }
            System.out.println("<<<< exception: {"+e.getMessage()+"}" );
            e.printStackTrace();
        } finally {
            if (response != null) {
                HttpEntity entity = response.getEntity();

                if (entity != null) {
                    try {
                        result = EntityUtils.toString(entity, "utf-8");
                        EntityUtils.consume(entity);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                System.out.println("<<<< response == null");
            }
        }
        System.out.println("http:get:result: {"+result+"}");
        return result;
    }

    /**
     * HTTP Post 获取内容
     * 
     * @param url     请求的url地址 ?之前的地址
     * @param params  请求的参数
     * @param charset 编码格式
     * @return 页面内容
     */
    public static <T extends Object> String doPost(String url, Map<String, T> params, String charset) {
        if (StringUtils.isBlank(url)) {
            return null;
        }
        System.out.println("
http:post:request:url: {"+url+"}, params:{"+params.toString()+"}" );
        CloseableHttpResponse response = null;
        String result = null;
        try {
            List<NameValuePair> pairs = null;
            if (params != null && !params.isEmpty()) {
                pairs = new ArrayList<>(params.size());
                for (Map.Entry<String, T> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        pairs.add(new BasicNameValuePair(entry.getKey(), value.toString()));
                    }
                }
            }
            HttpPost httpPost = new HttpPost(url);
            if (pairs != null && pairs.size() > 0) {
                httpPost.setEntity(new UrlEncodedFormEntity(pairs, CHARSET));
            }
            response = httpClient.execute(httpPost);
            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != 200) {
                httpPost.abort();
                throw new RuntimeException("HttpClient,error status code :" + statusCode);
            }
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                result = EntityUtils.toString(entity, "utf-8");
            }
            EntityUtils.consume(entity);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
            response = null;
        }
        System.out.println("http:post:result: {"+result+"}");
        return result;
    }



    /**
     * 发送HTTP Delete请求
     * 类似于GET
     * @param url     请求的url地址 ?之前的地址
     * @param params  请求的参数
     * @return 页面内容
     */
    public static <T extends Object> String doDelete(String url, Map<String, T> params, Map<String, String> headers) {
        if (StringUtils.isBlank(url)) {
            return null;
        }

        System.out.println("http:delete:request:url: {"+url+"}, params:{"+params+"}");
        CloseableHttpResponse response = null;
        String result = null;

        HttpDelete httpDelete = null;
        try {
            if (params != null && !params.isEmpty()) {
                List<NameValuePair> pairs = new ArrayList<>(params.size());
                for (Map.Entry<String, T> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        pairs.add(new BasicNameValuePair(entry.getKey(), value.toString()));
                    }
                }
                url += "?" + EntityUtils.toString(new UrlEncodedFormEntity(pairs, CHARSET));
            }
            System.out.println("url: {"+url+"}");
            httpDelete = new HttpDelete(url);
            // header
            if (headers != null && !headers.isEmpty()) {
                for (String key : headers.keySet()) {
                    httpDelete.setHeader(key, headers.get(key));
                }
            }

            response = httpClient.execute(httpDelete);

            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != 200) {
                httpDelete.abort();
                throw new RuntimeException("HttpClient,error status code :" + statusCode);
            }

        } catch (Exception e) {
            if (httpDelete != null) {
                httpDelete.abort();
            }
            System.out.println("<<<< exception: {"+e.getMessage()+"}" );
            e.printStackTrace();
        } finally {
            if (response != null) {
                HttpEntity entity = response.getEntity();

                if (entity != null) {
                    try {
                        result = EntityUtils.toString(entity, "utf-8");
                        EntityUtils.consume(entity);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                System.out.println("<<<< response == null");
            }
        }
        System.out.println("http:delete:result: {"+result+"}");
        return result;
    }


    /**
     * HTTP Put 获取内容
     * 类似于POST
     * @param url     请求的url地址 ?之前的地址
     * @param params  请求的参数
     * @return 页面内容
     */
    public static <T extends Object> String doPut(String url, Map<String, T> params) {
        if (StringUtils.isBlank(url)) {
            return null;
        }
        System.out.println("
http:post:request:url: {"+url+"}, params:{"+params.toString()+"}" );
        CloseableHttpResponse response = null;
        String result = null;
        try {
            List<NameValuePair> pairs = null;
            if (params != null && !params.isEmpty()) {
                pairs = new ArrayList<>(params.size());
                for (Map.Entry<String, T> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        pairs.add(new BasicNameValuePair(entry.getKey(), value.toString()));
                    }
                }
            }
            HttpPut httpPut = new HttpPut(url);
            if (pairs != null && pairs.size() > 0) {
                httpPut.setEntity(new UrlEncodedFormEntity(pairs, CHARSET));
            }
            response = httpClient.execute(httpPut);
            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != 200) {
                httpPut.abort();
                throw new RuntimeException("HttpClient,error status code :" + statusCode);
            }
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                result = EntityUtils.toString(entity, CHARSET);
            }
            EntityUtils.consume(entity);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                }
            }
            response = null;
        }
        System.out.println("http:post:result: {"+result+"}");
        return result;
    }

}