如何在Spring中将值从控制器传递到JSP页面？

Question

I'm trying to pass data from a Controller to a JSP page but I'm running into a few issues. There's a method in the Controller that will query a database of house price information based on a latitude and longitude value provided by a user. A debug shows that the database is queried correctly as it prints a houseprice value and the number of houses in the results to Eclipe's console but I can't get the JSP page to load and therefore get it to print to the JSP page.

 @RequestMapping(value = "/parseHousePrice", method={RequestMethod.POST, RequestMethod.GET})
 public @ResponseBody String parseHousePrice(@RequestBody HousePrice housePriceObject, 
                                             @RequestParam("latitude") double latitude,
                                             @RequestParam("longitude") double longitude, 
                                             Model model) {

  double housePriceAverage = parseHousePrice.ParseHousePrice(latitude, longitude);

  // This passes the lat & long into a method that will query the database
  List<Double> housePriceList = parseHousePrice.getList();
  // This will return the number of houses that were queried
  int housePriceListSize = housePriceList.size();

  // This print statement successfully prints the results fromt he query
  System.out.println("The average house price for this area is: " + housePriceAverage + " based on " + housePriceListSize + " property prices in this area");

  model.addAttribute("houseprice", housePriceAverage);
  model.addAttribute("housepricelistsize", housePriceListSize);

  // JSP Page I'm trying to pass the information above to
  return "houseprice"; 
}

The data is sent via an AJAX request in a Javascript function on one JSP and I'm trying to open a new JSP page with the information from the controller

   function parseHousePrice(){

       // Calculates users latitude and longitude
       $('.search_latitude').val(marker.getPosition().lat());
       var Lat = marker.getPosition().lat();
       console.log(Lat);

       $('.search_longitude').val(marker.getPosition().lng());
       var Long = marker.getPosition().lng();
       console.log(Long);

       $.ajax({
                type: "POST",
                url: "/parseHousePrice",
                data: { latitude: Lat, 
                        longitude: Long,  
                      }, 
                datatype: 'json'
       });

    }

And I call it from a link in a navbar like so:

 <li><a href= "javascript:parseHousePrice();" >House Price</a></li>

In the JSP page I've tried a few ways to collect the information calculated above and display it. One way was use thymleaf but this won't print

 <h4>Average House Price <text th:text="${houseprice}" /> </h4>
 <h4>Number of Houses the average is caluclated by: <text th:text="${housepricelistsize}" /> </h4>

Another way was to drop the thymeleaf and call it like this:

 <h1>${houseprice} </h1>
 <h1>${housepricelistsize} </h1> 

However, there is no luck. I can get the information successfully passed into the controller and printed into the console, but passing it from the controller to the JSP page is where I'm having trouble. Any help would be appreciated!

Screenshot of application

Answer 1

As far as I understand, you are trying to update your jsp page with house price and size when navbar is clicked. I am trying to answer this based on what I understand.

In your jsp I would put something like,

<h1 id ="housepriceID"></h1>
 <h1 id ="housepricesize"> </h1>

Now on your jQuery,

$.ajax({
                type: "POST",
                url: "/parseHousePrice",
                data: { latitude: Lat, 
                        longitude: Long,  
                      }, 
                datatype: 'json'
       })
.done(function( data, textStatus, jqxhr ) {    
    $("#housepriceID").val(data.houseprice);
    $("#housepricesize").val(data.housepricelistsize);

            });

This should solve your problem.

Answer 2

如果我没看错，代码model.addAttribute应该是model.setAttribute ，因为您要将从数据库查询的数据添加到会话中，因此必须改用.setAttribute 。