@ControllerAdvice可以全局扩展Controller的功能，里面有三个注解
@ExceptionHandler、@InitBinder、@ModelAttribute，这三个注解都或被作用到@RequestMapping注解的方法上。

@ExceptionHandler 全局异常处理

@ControllerAdvice
public class MyControllerAdvice {
    /**
     * 把值绑定到Model中，使全局@RequestMapping可以获取到该值
     * @param model
     */
    @ModelAttribute
    public void addAttributes(Model model) {
        model.addAttribute("author", "Magical Sam");
    }

    /**
     * 全局异常捕捉处理
     * @param ex
     * @return
     */
    @ResponseBody
    @ExceptionHandler(value = Exception.class)
    public Map errorHandler(Exception ex) {
        Map map = new HashMap();
        map.put("code", 100);
        map.put("msg", ex.getMessage());
        return map;
    }

}

@InitBinder 数据绑定，

比如类型转换，

@InitBinder
protected void initBinder(WebDataBinder binder) {
         binder.registerCustomEditor(Date.class, new MyDateEditor());
        binder.registerCustomEditor(Double.class, new DoubleEditor()); 
        binder.registerCustomEditor(Integer.class, new IntegerEditor());
    }
private class MyDateEditor extends PropertyEditorSupport {
        @Override
        public void setAsText(String text) throws IllegalArgumentException {
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            Date date = null;
            try {
                date = format.parse(text);
            } catch (ParseException e) {
                format = new SimpleDateFormat("yyyy-MM-dd");
                try {
                    date = format.parse(text);
                } catch (ParseException e1) {
                }
            }
            setValue(date);
        }
    }
    
    public class DoubleEditor extends PropertiesEditor  {    
        @Override    
        public void setAsText(String text) throws IllegalArgumentException {    
            if (text == null || text.equals("")) {    
                text = "0";    
            }    
            setValue(Double.parseDouble(text));    
        }    
        
        @Override    
        public String getAsText() {    
            return getValue().toString();    
        }    
    }  
    
    public class IntegerEditor extends PropertiesEditor {    
        @Override    
        public void setAsText(String text) throws IllegalArgumentException {    
            if (text == null || text.equals("")) {    
                text = "0";    
            }    
            setValue(Integer.parseInt(text));    
        }    
        
        @Override    
        public String getAsText() {    
            return getValue().toString();    
        }    
    } 

映射对象

@Controller  
@RequestMapping("/test")  
public class TestController {  

@InitBinder  
private void initBinder(WebDataBinder binder){  
    //由表单到JavaBean赋值过程中哪一个值不进行赋值  
    binder.setDisallowedFields("lastName");  
} 

// 绑定变量名字和属性，参数封装进类  
    @InitBinder("user")  
    public void initBinderUser(WebDataBinder binder) {  
        binder.setFieldDefaultPrefix("user.");  
    }  
    // 绑定变量名字和属性，参数封装进类  
    @InitBinder("addr")  
    public void initBinderAddr(WebDataBinder binder) {  
        binder.setFieldDefaultPrefix("addr.");  
    }  
      
      
    @RequestMapping("/test")  
    @ResponseBody  
    public Map<String,Object> test(HttpServletRequest request,@ModelAttribute("user") User user,@ModelAttribute("addr") Addr addr){  
        Map<String,Object> map=new HashMap<String,Object>();  
        map.put("user", user);  
        map.put("addr", addr);  
        return map;  
    } 

@ModelAttribute 数据模型处理

//或者 通过@ModelAttribute获取

@RequestMapping("/home")
public String home(@ModelAttribute("author") String author) {
    System.out.println(author);
}

参看：https://blog.csdn.net/hehe520347/article/details/80090916