针对时间精度，默认为毫秒

[huangfuProject]

Purpose of this pull request

解决JdbcUtil格式化时间戳转换为毫秒和提取纳秒的精度问题，修改为默认单位为毫秒，不再进行多余的判断，因为无法判断传入的时间戳是什么类型的

Which issue you fix

Fixes # (1699).

Checklist:

• [ yes ] I have executed the 'mvn spotless:apply' command to format my code.
• [ yes ] I have a meaningful commit message (including the issue id, the template of commit message is '[label-type-#issue-id][fixed-module] a meaningful commit message.')
• [ yes ] I have performed a self-review of my own code.
• [ yes ] I have commented my code, particularly in hard-to-understand areas.
• [yes ] I have made corresponding changes to the documentation.
• [ yes ] I have added tests that prove my fix is effective or that my feature works.
• [ yes ] New and existing unit tests pass locally with my changes.
• [ yes ] I have checked my code and corrected any misspellings.
• [ yes ] My commit is only one. (If there are multiple commits, you can use 'git squash' to compress multiple commits into one.)