In the JSP program I replaced the original image with the new image (name, the same format), why open the page display or the previous picture?

Old picture resources are cached by the browser, even if you change the new picture, the program is the default to get the picture from the cache, the solution has a lot of, the simplest is when you change the picture when you clean up the browser cache,
Ctrl+f5 strong brush, some browsers may not be useful, and if your program is directly uploaded on the server side of the update, it is recommended to use static resources version control.

In the JSP program I replaced the original image with the new image (name, the same format), why open the page display or the previous picture?