参考：

Java 11 – String.repeat()介绍
https://blog.csdn.net/w116858389/article/details/116644332

New String APIs/Methods in Java 11
https://www.javaguides.net/2018/08/java-string-class-api-guide.html

java中将字符(Char)转换为字符串的四种方式
http://www.jquerycn.cn/a_17663

Java字符串篇-2-String类几个常见构造方法
https://blog.csdn.net/u011541946/article/details/79854672

android开发中byte[]转换成String
https://blog.csdn.net/u010477502/article/details/51854261

[转] java byte[] hex打印
https://www.cnblogs.com/tinyos/p/7208709.html

JAVA byte数组转化为16进制字符串输出
https://blog.csdn.net/x_iya/article/details/54136799

Android byte字节数组转换十六进制字符串（物联网开发总结）
https://blog.csdn.net/qq_31939617/article/details/82413926

android byte字节数组转换十六进制字符串
https://blog.csdn.net/zhao_liwei/article/details/51985391

Android MD5后 bye数组转化为Hex字符串的坑（记一次为女神排忧解难的经历）
https://cloud.tencent.com/developer/article/1132772

Andrid打印数组的方法
https://blog.csdn.net/Sunxiaolin2016/article/details/90080355