import java.io.File;
import java.security.cert.CertificateException;
import java.util.List;
import java.util.Map;

import javax.net.ssl.SSLContext;

import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContexts;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.client.RestTemplate;

    public String test_getssoinfo() throws Exception {
        
        TrustStrategy acceptingTrustStrategy = new TrustStrategy() {

            @Override
            public boolean isTrusted(java.security.cert.X509Certificate[] chain,
                    String authType) throws CertificateException {
                System.out.println("in isTrusted" );
                // TODO 完成方法實現
                return true;
            }
        } ;

        SSLContext sslContext = org.apache.http.ssl.SSLContexts.custom()
                .loadTrustMaterial(null, acceptingTrustStrategy)
                .build();

        SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext);

        CloseableHttpClient httpClient = HttpClients.custom()
                .setSSLSocketFactory(csf)
                .build();

        HttpComponentsClientHttpRequestFactory requestFactory =
                new HttpComponentsClientHttpRequestFactory();

        requestFactory.setHttpClient(httpClient);
        
        RestTemplate restTemplate = new RestTemplate(requestFactory);
//        RestTemplate restTemplate = new RestTemplate();
        String userJsonStr = restTemplate.getForObject("https://www.xxx.yy/", String.class);
        return userJsonStr;
    }
 

okhttp:

X509TrustManager trustManager = new X509TrustManager()
			{
				@Override
				public void checkClientTrusted(java.security.cert.X509Certificate[] arg0, String arg1) throws java.security.cert.CertificateException
				{
				}
				@Override
				public void checkServerTrusted(java.security.cert.X509Certificate[] arg0, String arg1) throws java.security.cert.CertificateException
				{
				}
				@Override
				public java.security.cert.X509Certificate[] getAcceptedIssuers()
				{
					StrUtil.log("getAcceptedIssuers()");
					return new X509Certificate[0];
				}
			};

			SSLContext sslContext = SSLContext.getInstance("SSL");
			sslContext.init(null, new X509TrustManager[] { trustManager }, new java.security.SecureRandom());
			SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();
			
			builder.sslSocketFactory(sslSocketFactory, trustManager).hostnameVerifier(new HostnameVerifier()
			{
				@Override
				public boolean verify(String hostname, SSLSession session)
				{
					StrUtil.log("verify() hostname:" + hostname + ", session:" + (session != null ? session.toString() : "null"));
					return true;
				}
			});