具体内容见:
Java并发编程之深入理解】Synchronized的使用
https://blog.csdn.net/zjy15203167987/article/details/82531772
String、StringBuffer和StringBuilder的区别
https://blog.csdn.net/csxypr/article/details/92378336
来源:CSDN
作者:没滴人称
链接:https://blog.csdn.net/weixin_42649617/article/details/104851068