Description of the problem:
Prompt needs to be formatted to indicate that the file system structure of this disk is damaged. How to find the specific recovery method that prompts you to format the removable disk file can be found in the text (Recovery Method Without Formatting) 
Tool / Software: Extreme Data Recovery
Step 1: First Baidu search and download software that opens, select the need to restore the disk, and then point "Start Restore" button 
Step 2: The software will soon be scanning data, to be restored into the tray with the same name directory 
Step 3 : Check all the data that needs to be restored, and then click the "Save As" button in the upper right corner to copy the checked files. 
Step 4: Just wait for the program to copy the data. 
Note 1: The data that needs to be formatted and recovered needs to be temporarily saved to another disk.
Note 2: If you want to restore the J drive, you need to format it. You must restore the data before formatting.