http://blog.****.net/baidu_18607183/article/details/51595330
https://blogs.oracle.com/java-platform-group/entry/diagnosing_tls_ssl_and_https
https://my.oschina.net/u/1024107/blog/780193
http://www.oracle.com/technetwork/java/javase/documentation/tlsreadme2-176330.html
http://blog.****.net/levy_cui/article/details/51143104
http://www.jianshu.com/p/4223bff0fcc2
http://www.oschina.net/question/2282830_247657 低版本JDK参考TLS冲突 http://blog.****.net/lizo_is_me/article/details/52490368 (http://*.com/questions/34887332/how-can-i-use-tls-1-2-in-java-6-with-an-apache-httpclient) -Djavax.net.debug=all
-Dsun.security.ssl.allowUnsafeRenegotiation=true
-Dsun.security.ssl.allowLegacyHelloMessages=true https://www.bouncycastle.org/ 《Beginning Cryptography with Java》 bouncycastle设置