FeignClient远程调用https协议，信任证书问题（No subject alternative names present）

通过@FeignClient调用https接口时，因为服务器加载了证书等问题，调用抛错如下：

Caused by: java.security.cert.CertificateException: No subject alternative names present
	at sun.security.util.HostnameChecker.matchIP(HostnameChecker.java:145)
	at sun.security.util.HostnameChecker.match(HostnameChecker.java:94)
	at sun.security.ssl.X509TrustManagerImpl.checkIdentity(X509TrustManagerImpl.java:455)
	at sun.security.ssl.X509TrustManagerImpl.checkIdentity(X509TrustManagerImpl.java:436)
	at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:200)
	at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496)
	... 97 more

经过研究，在客户端配置服务端证书也可以解决，但相对比较麻烦，故采用配置文件的形式信任证书即可：

import feign.Client;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.cloud.netflix.feign.ribbon.CachingSpringLoadBalancerFactory;
import org.springframework.cloud.netflix.feign.ribbon.LoadBalancerFeignClient;
import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.net.ssl.*;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

@Configuration
public class FeignHttpsConfig {

    @Bean
    @ConditionalOnMissingBean
    public Client feignClient(CachingSpringLoadBalancerFactory cachingFactory,SpringClientFactory clientFactory) throws NoSuchAlgorithmException, KeyManagementException {
        SSLContext ctx = SSLContext.getInstance("TLSv1.2");// "SSL"
        X509TrustManager tm = new X509TrustManager() {

            @Override
            public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {

            }

            @Override
            public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {

            }

            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return new X509Certificate[0];
            }
        };
        ctx.init(null, new TrustManager[]{tm}, null);
        return new LoadBalancerFeignClient(new Client.Default(ctx.getSocketFactory(),
                new HostnameVerifier() {
                    public boolean verify(String hostname, SSLSession sslSession) {
                        return true;
                    }
                }),
                cachingFactory, clientFactory);
    }
}