一个封装的使用Apache HttpClient进行Http请求（GET、POST、PUT等）的类。

import com.qunar.payment.gateway.front.channel.mpgs.po.HttpReqEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.springframework.http.HttpMethod;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.IOException;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.cert.X509Certificate;

/**
* User:xfyou Date:2017/11/23 10:50
*/
public class HttpUtil {
private HttpUtil() {
}

private static CredentialsProvider credentialsProvider;
private static final SSLConnectionSocketFactory SOCKET_FACTORY = getSocketFactory();
private static final NoopHostnameVerifier NO_OP = new NoopHostnameVerifier();

public static String execute(HttpReqEntity httpReqEntity) throws IOException {
CloseableHttpClient httpclient = getClosableHttpClient(httpReqEntity);
CloseableHttpResponse response = null;
try {
response = httpclient.execute(getHttpUriRequest(httpReqEntity));
return EntityUtils.toString(response.getEntity());
} finally {
try {
if (null != response) response.close();
if (null != httpclient) httpclient.close();
} catch (IOException ignored) {
}
}
}

private static TrustManager getTrustManagers() {
return new X509TrustManager() {
public X509Certificate[] getAcceptedIssuers() {
return null;
}

public void checkClientTrusted(X509Certificate[] certs, String authType) {
}

public void checkServerTrusted(X509Certificate[] certs, String authType) {
}
};
}

private static SSLConnectionSocketFactory getSocketFactory() {
SSLContext sslContext;
try {
sslContext = SSLContext.getInstance(MpgsConstant.SECURITYPROTOCOL_VERSION_TLS_1_2);
} catch (NoSuchAlgorithmException e) {
return null;
}
try {
sslContext.init(null, new TrustManager[]{getTrustManagers()}, new SecureRandom());
} catch (KeyManagementException e) {
return null;
}
return new SSLConnectionSocketFactory(sslContext);
}

private static CloseableHttpClient getClosableHttpClient(HttpReqEntity entity) {
return HttpClients.custom()
.setSSLSocketFactory(SOCKET_FACTORY)
.setSSLHostnameVerifier(NO_OP)
.setDefaultCredentialsProvider(getCredentialsProvider(entity.getCredUserName(), entity.getCredPasswd()))
.build();
}

private static HttpPut getHttpPut(String requestUrl, String requestMessage, RequestConfig config) {
HttpPut httpPut = new HttpPut(requestUrl);
httpPut.setConfig(config);
httpPut.addHeader(HttpHeaders.CONTENT_TYPE, MpgsConstant.CONTENTTYPE_JSON);
httpPut.setEntity(new StringEntity(requestMessage, MpgsConstant.CHARSET_UTF8));
return httpPut;
}

private static HttpGet getHttpGet(String requestUrl, RequestConfig config) {
HttpGet httpGet = new HttpGet(requestUrl);
httpGet.setConfig(config);
return httpGet;
}

private static HttpUriRequest getHttpUriRequest(HttpReqEntity entity) {
return entity.getHttpMethod() == HttpMethod.GET ? getHttpGet(entity.getRequestUrl(), entity.getRequestConfig())
: getHttpPut(entity.getRequestUrl(), entity.getRequestMessage(), entity.getRequestConfig());
}

private static CredentialsProvider getCredentialsProvider(String userName, String passwd) {
if (null == credentialsProvider) {
synchronized (HttpUtil.class) {
if (null == credentialsProvider) {
CredentialsProvider credsProvider = new BasicCredentialsProvider();
credsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(userName, passwd));
credentialsProvider = credsProvider;
}
}
}
return credentialsProvider;
}
}