Java spring MVC gets / publishes in the same JSP

This is my controller

@RequestMapping(value = "/add",method = RequestMethod.GET)
public String add(Model model) {
    return "add";
}

@RequestMapping(value = "/add",method = RequestMethod.POST)
public String added(@RequestParam("name") String name,Model model) {
    City city = new City();
    city.setCity(name);
    service.addCity(city);
    return "add";
}

This is my JSP view This is just to add... This is add jsp.. So send it back to yourself

<form method="post" action="/spring/krams/edit/add">
Linna nimi
<input type="text" name="name">
<input type="submit" value="Test" name="submit" />
</form>

I want the JSP file to change so that when I publish it to this file, it will say... "City added." Is that possible?

What about updating the city?

@RequestMapping(value = "/update",method = RequestMethod.POST)
public String updated(@RequestParam("city") int city_id,@RequestParam("text") String name,Model model) {
    service.updateCity(name,city_id);
    return "update";
}

There's no object here?

Solution

In the post method, you can add attributes using the addAttribute method

@RequestMapping(value = "/add",Model model) {
    City city = new City();
    city.setCity(name);
    service.addCity(city);
    model.addAttribute("city",city);
    return "add";
}

In JSP, you can check whether the attribute city is null (marked < C: if / >) If it's not null, it's because it's just added to the model, so you can display anything you want$ {city.city} is just a JSTL expression that accesses the city attribute and then calls getter to access the city attribute of the attribute:

<%@ taglib uri="http://java.sun.com/jstl/core_rt" prefix="c" %>

<c:if test="${city != null}">
    CITY <c:out value="${city.city}" /> ADDED
</c:if>

UPDATE

If different messages are required according to the update / create operation, the following operations can be performed: (in the example, update when ID param is not null, because ID is the identifier of the city to be updated)

@RequestMapping(value = "/add",method = RequestMethod.POST)
public String added(@RequestParam(value="id",required=false) String id,@RequestParam("name") String name,Model model) {
    City city;
    String operation;
    if(id== null){
        //create operation
        city = new City();
        operation = "CREATE";

    }else{
        //update operation
        city = service.findCity(id);
        operation = "UPDATE";
    }
    city.setCity(name);        
    service.saveCity(city); //save or update
    model.addAttribute("city",city);
    model.addAttribute("operation",operation); //add operation param
    return "add";
}

In JSP, you can:

<%@ taglib uri="http://java.sun.com/jstl/core_rt" prefix="c" %>

<c:if test="${operation == 'CREATE'}">
    <c:if test="${city != null}">
          CITY <c:out value="${city.city}" /> ADDED
    </c:if>
    <c:if test="${operation == 'UPDATE'}">
          CITY <c:out value="${city.city}" /> UPDATED
    </c:if>
</c:if>