SpringMVC Returning a List Of Objects With JSON

Question

I have two select options and i would like when the user selects one option that other is populated with data from the database. However i am having issues in getting the object list returned to the view. Controller ``` @RequestMapping(value="getCrimeTypeList.htm", method = RequestMethod.GET) public @ResponseBody List getCrimeTypeList(@RequestParam(value="crimeCatId") Integer crimeCatId) throws Exception{ try { List crimeTypeList = this.crimeTypeManager.getCrimeTypeList(crimeCatId); return crimeTypeList; } catch (Exception e) { logger.error(e.getMessage()); return null; } } ``` JQuery ``` $("select#offenceCatId").change(function(){ $.ajax({ type:'GET', url:'getCrimeTypeList.htm', data:{crimeCatId: $(this).val()}, headers: { Accept: 'application/json' }, dataType: 'json', success:function(data){ alert('it worked'); } }); }); ``` HTML ```

Offence Type

Accepted Answer

Firstly please make sure your Spring version is 3.1.1 release and you have added jackson.jar in you lib, then try using below code, your code has something reduntant.

```
@RequestMapping(value="/getCrimeTypeList.htm", method = RequestMethod.GET)
public @ResponseBody List<CrimeType> getCrimeTypeList(@RequestParam(value="crimeCatId") Integer crimeCatId) throws Exception{    
            try {
                return this.crimeTypeManager.getCrimeTypeList(crimeCatId);
                //return "true";
            } catch (Exception e) {
                logger.error(e.getMessage());
                return null;
            }
}
```

```
$("select#offenceCatId").change(function(){
        var param={crimeCatId:$(this).val()};
        $.ajax({
            type:'GET',
            url:'getCrimeTypeList.htm',
            data:param,
            success:function(data){
                //append options to list
            }
        });
});
```

SpringMVC Returning a List Of Objects With JSON

Solution

Problem