Why refresh the page and repeat the last message?

Why refresh the page and repeat the last message?

 

 
 
  
  
// The Form style is in the middle, skipped
    
  
  
 
   
 
    
Title: 
 
    
User: 
 
    
 
 
   
 
   
 
    
Content: 
 
   
  
  
 
 

Reply to discussion (solution)

  
 
Php doesn't quite understand. but from the perspective of jsp, if the request page data is put in the session, that's the problem.
 
What you omitted is the most likely cause.
 
After submission, jump to the header.
 
Can I post your submission page to locate the problem.
 
Add a form token to verify against repeated submission
 
I still want to paste them all ..