Spring MVC入门（十）：异常处理

异常处理

• 简介

SpringMVC提供了一个处理控制器方法执行过程中所出现的异常的接口：HandlerExceptionResolver
HandlerExceptionResolver接口的实现类有：DefaultHandlerExceptionResolver和
SimpleMappingExceptionResolver
SpringMVC提供了自定义的异常处理器SimpleMappingExceptionResolver

• 双击shift，搜索DefaultHandlerExceptionResolver
  

• ctrl + h 选中AbstractHandlerExceptionResolver
  

• 查看DefaultHandlerExceptionResolver源码，当出现异常时，返回1个新的ModelAndView替换我们自己的ModelAndView

        @Override
	@Nullable
	protected ModelAndView doResolveException(
			HttpServletRequest request, HttpServletResponse response, @Nullable Object handler, Exception ex) {

		try {
			if (ex instanceof HttpRequestMethodNotSupportedException) {
				return handleHttpRequestMethodNotSupported(
						(HttpRequestMethodNotSupportedException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMediaTypeNotSupportedException) {
				return handleHttpMediaTypeNotSupported(
						(HttpMediaTypeNotSupportedException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMediaTypeNotAcceptableException) {
				return handleHttpMediaTypeNotAcceptable(
						(HttpMediaTypeNotAcceptableException) ex, request, response, handler);
			}
			else if (ex instanceof MissingPathVariableException) {
				return handleMissingPathVariable(
						(MissingPathVariableException) ex, request, response, handler);
			}
			else if (ex instanceof MissingServletRequestParameterException) {
				return handleMissingServletRequestParameter(
						(MissingServletRequestParameterException) ex, request, response, handler);
			}
			else if (ex instanceof ServletRequestBindingException) {
				return handleServletRequestBindingException(
						(ServletRequestBindingException) ex, request, response, handler);
			}
			else if (ex instanceof ConversionNotSupportedException) {
				return handleConversionNotSupported(
						(ConversionNotSupportedException) ex, request, response, handler);
			}
			else if (ex instanceof TypeMismatchException) {
				return handleTypeMismatch(
						(TypeMismatchException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMessageNotReadableException) {
				return handleHttpMessageNotReadable(
						(HttpMessageNotReadableException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMessageNotWritableException) {
				return handleHttpMessageNotWritable(
						(HttpMessageNotWritableException) ex, request, response, handler);
			}
			else if (ex instanceof MethodArgumentNotValidException) {
				return handleMethodArgumentNotValidException(
						(MethodArgumentNotValidException) ex, request, response, handler);
			}
			else if (ex instanceof MissingServletRequestPartException) {
				return handleMissingServletRequestPartException(
						(MissingServletRequestPartException) ex, request, response, handler);
			}
			else if (ex instanceof BindException) {
				return handleBindException((BindException) ex, request, response, handler);
			}
			else if (ex instanceof NoHandlerFoundException) {
				return handleNoHandlerFoundException(
						(NoHandlerFoundException) ex, request, response, handler);
			}
			else if (ex instanceof AsyncRequestTimeoutException) {
				return handleAsyncRequestTimeoutException(
						(AsyncRequestTimeoutException) ex, request, response, handler);
			}
		}
		catch (Exception handlerEx) {
			if (logger.isWarnEnabled()) {
				logger.warn("Failure while trying to resolve exception [" + ex.getClass().getName() + "]", handlerEx);
			}
		}
		return null;
	}

• 实现代码

# springmvc配置文件中配置异常处理
    
        
            
                error
            
        
        
        
    

# 编写错误页面



    
    


出现错误




# 模拟1个异常
    @RequestMapping("/testExceptionHandler")
    public String testExceptionHandler(){
        System.out.println(1/0);
        return "success";
    }

• 注解配置异常处理

# 注释掉springmvc配置文件中配置异常处理
    
        
            
                error
            
        
        
        
    

# 编写错误页面



    
    


出现错误




# 模拟1个异常
    @RequestMapping("/testExceptionHandler")
    public String testExceptionHandler(){
        System.out.println(1/0);
        return "success";
    }

# 异常处理配置
@ControllerAdvice
public class ExceptionController {
    // 出现如下异常时跳转到错误页面
    @ExceptionHandler(value = {ArithmeticException.class, NullPointerException.class})
    public String testException(Exception ex, Model model){    // 将错误信息通过model设置到域对象中，前端可以获取
        model.addAttribute("ex", ex);
        return "error";
    }

}