apache httpclient 4.5 兼容 http https

String responseContent = "";
try {
    SSLContextBuilder contextBuilder = new SSLContextBuilder();
    contextBuilder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
    SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(contextBuilder.build());
    CloseableHttpClient httpclient = HttpClients.custom().setSSLSocketFactory(sslConnectionSocketFactory).build();
    HttpGet httpGet = new HttpGet(requestUrl);
    CloseableHttpResponse response = httpclient.execute(httpGet);
    try {
        HttpEntity entity = response.getEntity();
        if (null != entity) {
            responseContent = EntityUtils.toString(entity, ContentType.getOrDefault(entity).getCharset());
            EntityUtils.consume(entity);
        }
    } finally {
        response.close();
    }
} catch (KeyStoreException e) {
    e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
    e.printStackTrace();
} catch (KeyManagementException e) {
    e.printStackTrace();
}
return responseContent;