import org.apache.commons.lang.StringUtils;

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.StatusLine;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.HttpClient;

import org.apache.http.client.HttpResponseException;

import org.apache.http.client.ResponseHandler;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.conn.ssl.SSLConnectionSocketFactory;

import org.apache.http.entity.StringEntity;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClientBuilder;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.util.EntityUtils;

import javax.net.ssl.SSLContext;

import javax.net.ssl.TrustManager;

import javax.net.ssl.X509TrustManager;

import java.io.IOException;

import java.security.cert.CertificateException;

import java.security.cert.X509Certificate;

public class PostUtil {

    /**

     * 发送post请求

     * @param url  请求地址

     * @param json  json格式字符串

     * @param contentType  这里用 "application/json"

     * @return

     */

    public static String post(String url, String json, String contentType) {

        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();

        //HttpClient

        CloseableHttpClient client = httpClientBuilder.build();

        client = (CloseableHttpClient) wrapClient(client);

        HttpPost post = new HttpPost(url);

        try {

            StringEntity s = new StringEntity(json, "utf-8");

            if (StringUtils.isBlank(contentType)) {

                s.setContentType("application/json");

            }

            s.setContentType(contentType);

            post.setEntity(s);

            HttpResponse res = client.execute(post);

            HttpEntity entity = res.getEntity();

            String str = EntityUtils.toString(entity, "utf-8");

            return str;

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }

    private static org.apache.http.client.HttpClient wrapClient(HttpClient base) {

        try {

            SSLContext ctx = SSLContext.getInstance("TLSv1");

            X509TrustManager tm = new X509TrustManager() {

                public void checkClientTrusted(X509Certificate[] xcs,

                                               String string) throws CertificateException {

                }

                public void checkServerTrusted(X509Certificate[] xcs,

                                               String string) throws CertificateException {

                }

                public X509Certificate[] getAcceptedIssuers() {

                    return null;

                }

            };

            ctx.init(null, new TrustManager[]{tm}, null);

            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(ctx, new String[]{"TLSv1"}, null,

                    SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);

            CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(sslsf).build();

            return httpclient;

        } catch (Exception ex) {

            return null;

        }

    }

    public class CharsetHandler implements ResponseHandler<String> {

        private String charset;

        public CharsetHandler(String charset) {

            this.charset = charset;

        }

        public String handleResponse(HttpResponse response)

                throws ClientProtocolException, IOException {

            StatusLine statusLine = response.getStatusLine();

            if (statusLine.getStatusCode() >= 300) {

                throw new HttpResponseException(statusLine.getStatusCode(),

                        statusLine.getReasonPhrase());

            }

            HttpEntity entity = response.getEntity();

            if (entity != null) {

                if (!StringUtils.isBlank(charset)) {

                    return EntityUtils.toString(entity, charset);

                } else {

                    return EntityUtils.toString(entity);

                }

            } else {

                return null;

            }

        }

    }

}