What is the difference between return"view" and return"redirect:view" in a POST method for Spring MVC?

If you use return "vista";the server it will perform a forward on sight. If you use return "redirect:vista";the server it will perform a redirect to the url associated with the view. With this in mind, your question translates to what are the differences between a forward and a redirect. These concepts are not associated with Spring but with the development of Web applications in Java.

forward

Your request will return a response with a code 200, 201 or another, for example 500 if an error occurs during the attention of the request. In this case, the content of the response will be the content of your view, that is, your JSP. The benefits are that you can reuse the attributes put in the request scope for use in rendering the view. That is, by using Forward you can do this:

Code in controller:

public String ejecutaPost(Model model) {
    model.add("saludo", "hola mundo!");
    return "vista";
}

Code in the view (usually JSP):

<p>El servidor manda un saludo: ${saludo}</p>

Redirect

Your request will return a response with a 300 HTTP code indicating that the client (the browser) has to make a new request to another url on the server (or perhaps an external server). The server will receive this request and serve it.

In this case, the attributes set at the request level cannot be used because a new request-response cycle will be generated towards the server.

What happens in your application is:

When you execute return"vista.jsp"you return the jsp to the browser, I guess when you say

returning it completely clean without information

It is that you have a controller that manages the requestuser and puts information in your vista.jsp, but this controller that you show does not have that logic, that's why it comes out "empty"

When you do a redirect:

A requestbrowser is started towards your url, so the associated controller can load the information, since at this moment it is entering the game

Small scheme of both cases

• Wikipedia URL redirection
• official documentation