@ControllerAdvice实现优雅地处理异常

小灰灰 2023-10-02 12:02 1阅读 0赞

@ControllerAdvice，是Spring3.2提供的新注解,它是一个Controller增强器,可对controller中被 @RequestMapping注解的方法加一些逻辑处理。最常用的就是异常处理

###### 统一异常处理 ######

需要配合@ExceptionHandler使用。  
当将异常抛到controller时,可以对异常进行统一处理,规定返回的json格式或是跳转到一个错误页面

//全局异常捕捉处理
    @ControllerAdvice
    public class CustomExceptionHandler {
        
    
        @ResponseBody
        @ExceptionHandler(value = Exception.class)
        public Map errorHandler(Exception ex) {
        
            Map map = new HashMap();
            map.put("code", 400);
            //判断异常的类型,返回不一样的返回值
            if(ex instanceof MissingServletRequestParameterException){
        
                map.put("msg","缺少必需参数："+((MissingServletRequestParameterException) ex).getParameterName());
            }
            else if(ex instanceof MyException){
        
                map.put("msg","这是自定义异常");
            }
            return map;
        }
    }

//自定义异常类
    @Data
    public class MyException extends RuntimeException {
        
        private long code;
        private String msg;
    
        public MyException(Long code, String msg){
        
            super(msg);
            this.code = code;
            this.msg = msg;
        }
    
        public MyException(String msg){
        
            super(msg);
            this.msg = msg;
        }
    }
    @RestController
    public class TestController {
        
        @RequestMapping("testException")
        public String testException() throws Exception{
        
            throw new MissingServletRequestParameterException("name","String");
        }
    
        @RequestMapping("testMyException")
        public String testMyException() throws MyException{
        
            throw new MyException("i am a myException");
        }
    }

分别访问`testException`和`testMyException`接口,可得到以下结果

{
        "msg":"缺少必需参数：name","code":400}
    {
        "msg":"这是自定义异常","code":400}

如果不需要返回json数据，而要渲染某个页面模板返回给浏览器，那么可以这么实现：

@ExceptionHandler(value = MyException.class)
    public ModelAndView myErrorHandler(MyException ex) {
        
        ModelAndView modelAndView = new ModelAndView();
        //指定错误页面的模板页
        modelAndView.setViewName("error");
        modelAndView.addObject("code", ex.getCode());
        modelAndView.addObject("msg", ex.getMsg());
        return modelAndView;
    }

这样子很方便吧~