Spring MVC JSP Jquery call controller method on button click post redirect error

Question

• Assumptions, I am new to Spring MVC, JSP, Scripting/Ajax

  Here's my task.

In Spring MVC, I have buttons in my jsp page, on button click, I want to perform some task (controller method), which doesn't return anything. I want to show the same page. It shouldn't reload the page nor should redirect to some other page.

Here's what I am doing...

1. I have a page with lots of buttons. I am using bootstrap css and button tag. like,

   Start

2. On this button click, I am calling an Ajax to the method from controller,

       $('#startApp').click(function() {
       BootstrapDialog.show({
           message : 'Sure ?!',
           buttons : [ {
               label : 'Ok',
               cssClass : 'btn-default',
               action : function(dialogItself) {
                   $.ajax({
                       type : "POST",
                       url : "/MyApp/startApp",
                       success : function(response) {
                           alert("Success");
                       }
                   });
   
                   dialogItself.close();
               }
           }, {
               label : 'Close',
               action : function(dialogItself) {
                   dialogItself.close();
               }
           } ]
       });
   

3. This calls the controller method,

        @RequestMapping(value = "/startApp", method = RequestMethod.POST)
           public void start() {// some operation.}
   

4. However, when I do this, operation is performed but in logs I am getting below error,

   root cause dispatcher: com.ibm.ws.jsp.webcontainerext.JSPErrorReport: JSPG0036E: Failed to find resource /WEB-INF/views/startApp.jsp

Questions,

• Is it the right way to do ?
• I don't want to redirect to startApp.jsp, I want it to return to my index.jsp (where the code resides), how can I achieve this ?

Answer 1

You need to return something to the client. Spring default tries to send back startApp.jsp because that's what in the url (/startApp). Try this: this will send back an HTTP OK status (200).

@RequestMapping("/startApp", method = RequestMethod.POST)
public ResponseEntity start()
{
    return new ResponseEntity(HttpStatus.OK);
}

You can also send back a json by returning a POJO (it'll be automatically serialized by the Jackson JSON lib) if that's what you want, or even a simple string as the html content by returning a String.

Answer 2

The purpose of ajax is to refresh a part of page. so re-directing to another page is meaningless, you could make the return type as String in your controller.

@RequestMapping(value = "/startApp", method = RequestMethod.POST)
@ResponseBody
        public String start() {
        // some operation
        return "sucess"
        }

Read my answer here Returning Hashmap From controller to JSP in Springmvc to know how to pass parameters in response