SpringMVC异常处理注解@ExceptionHandler

关于@ExceptionHandler注解不详细说明，次记录仅供参考，直接贴项目中的代码用法，不喜勿喷，不足之处请指点。

Controller：

1.controller继承异常基类BaseController 

public class BaseController {
    
    protected Logger logger = LoggerFactory.getLogger(getClass());
        
    @ExceptionHandler
    public @ResponseBody Object exceptionHandler(Exception exception, HttpServletResponse response) {
        if (exception instanceof BException) {
            exception.printStackTrace();
            logger.error(exception.getMessage());
            return JsonResult.error(((BException) exception).getMsg());
        }else {
            exception.printStackTrace();
            logger.error(exception.getMessage());
            return JsonResult.error("系统发生错误。");
        }
    }

}

BException：

2.自定义异常BException，继承RuntimeException

public class BException extends RuntimeException{
    private static final long serialVersionUID = 1L;
    private String msg;//错误消息
    private boolean async; //是否异步
    
    public BException(){
        super();
    }
    
    public BException(String msg) {
        super(msg);
        this.async = false;
        this.msg = msg;
    }
    
    public BException(Exception e){
        super(e.getMessage());
        this.async = false;
        if(e instanceof BException){
            BException self = (BException) e;
           this.msg = self.getMsg();
        }else{
            this.msg = e.getMessage();
        }
        
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public boolean isAsync() {
        return async;
    }

    public void setAsync(boolean async) {
        this.async = async;
    }
}

Service：

3.在service层直接使用自定义的异常类，将异常抛出到controller，因为controller继承异常基类BaseController ，所以service中相关的异常BaseController会处理

    public Map<String, Object> findRank(String account) throws BException{
        List<Map<String, Object>> list = dao.findRank(account);
        if(list == null || list.isEmpty())
            throw new BException("未找到再生值排名");
        
        Map<String, Object> map = list.get(0);
        return map;
    }