java面试题：为什么 StringBuilder 不是线程安全的？
https://blog.csdn.net/qq_43563538/article/details/100537328
java String类常见面试题
https://blog.csdn.net/chaobin6/article/details/81214980
深入理解Java String类
https://blog.csdn.net/ifwinds/article/details/80849184?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-3.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-3.nonecase
深入理解Java中的String（大坑）
https://blog.csdn.net/qq_34490018/article/details/82110578?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase
java面试之string
原文：https://www.cnblogs.com/windy13/p/13167001.html
