https://www.nowcoder.com/discuss/788605?source_id=discuss_experience_nctrack&channel=-1

String类是final char[]数组实现的，注意这个是java8的时候，java9变成了byte[]

https://cdn.nlark.com/yuque/0/2021/png/576791/1633902781908-ae318647-3d01-4dd8-8d50-17fcfad68acc.png#from=url&id=N6zqC&originHeight=133&originWidth=598&originalType=binary&ratio=1&status=done&style=none