Java8 新特性实战中的字符串转日期格式

[字符串转日期格式](https://javaguide.cn/java/new-features/java8-common-new-features.html#%E5%AD%97%E7%AC%A6%E4%B8%B2%E8%BD%AC%E6%97%A5%E6%9C%9F%E6%A0%BC%E5%BC%8F)
这里
```java
LocalDateTime.parse("2021-01-26 12:12:22");
```
应该改为
```java
LocalDateTime.parse("2021-01-26T12:12:22");
```