如何向Spring MVC REST服务添加错误？

Question

如果用户没有输入我编码的两个名称,如何从Spring MVC更改/更新以下REST调用以返回错误..类似于未找到的东西？

@RequestMapping(value = "/{name}", method = RequestMethod.GET)
    @ResponseBody
    public User getName(@PathVariable String name, ModelMap model)
    {

        logger.debug("I am in the controller and got user name: " + name);

        /*

            Simulate a successful lookup for 2 users, this is where your real lookup code would go

         */

        if ("name2".equals(name))
        {
            return new User("real name 2", name);
        }

        if ("name1".equals(name))
        {
            return new User("real name 1", name);
        }


        return null;
    }

Answer 1

定义一个新的异常类,例如ResourceNotFoundException,从带注释的控制器方法中抛出一个这样的实例getName.

然后还在Controller类中定义带注释的异常处理程序方法来处理该异常,并返回404 Not Found状态代码,可能会记录它.

@ExceptionHandler(ResourceNotFoundException.class)
@ResponseStatus(value = HttpStatus.NOT_FOUND)
public void handleResourceNotFoundException(ResourceNotFoundException ex)
{
    LOG.warn("user requested a resource which didn't exist", ex);
}

甚至使用@ResponseBody注释返回一些错误消息:

@ExceptionHandler(ResourceNotFoundException.class)
@ResponseStatus(value = HttpStatus.NOT_FOUND)
@ResponseBody
public String handleResourceNotFoundException(ResourceNotFoundException ex)
{
    return ex.getMessage();
}