Spring Boot 中提供了默认的异常处理，但是对于应用来说，这些信息并不应该直接返回或者不够明确，需要结合自己的情况进行定制。
自定义处理异常有两种方式:
- org.springframework.web.servlet.HandlerExceptionResolver#resolveException
- org.springframework.web.bind.annotation.RestControllerAdvice或org.springframework.web.bind.annotation.ControllerAdvice和org.springframework.web.bind.annotation.ExceptionHandler注解来实现
当两种方式都实现时，HandlerExceptionResolver要先于ControllerAdvice执行
使用 HandlerExceptionResolver 处理异常
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| public class CustomExceptionHandlerResolver implements HandlerExceptionResolver {
private static final ObjectMapper OBJECT_MAPPER;
static {
OBJECT_MAPPER = new ObjectMapper();
OBJECT_MAPPER.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
OBJECT_MAPPER.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
OBJECT_MAPPER.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
}
@Override
public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
String message = "服务器错误";
if (o instanceof HandlerMethod) {
if (e instanceof IllegalArgumentException) {
message = "参数错误";
} else if (e instanceof SecurityException) {
message = "不允许访问";
} else if (e instanceof NullPointerException) {
message = "空指针异常";
}
} else if (e instanceof NoHandlerFoundException) {
message = "未找到相应资源";
} else if (e instanceof HttpMediaTypeNotSupportedException) {
message = "请求类型不支持";
}
httpServletResponse.setCharacterEncoding(StandardCharsets.UTF_8.name());
httpServletResponse.setContentType(MediaType.APPLICATION_JSON_UTF8_VALUE);
try {
httpServletResponse.getWriter()
.write(
OBJECT_MAPPER.writeValueAsString(
CustomResponseContent.builder()
.code(500)
.status("fail")
.message(message)
.build()
)
);
} catch (IOException ex) {
ex.printStackTrace();
}
return new ModelAndView();
}
}
|
还需要将该配置添加到应用中
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| @Configuration
public class CustomWebMvcConfigurer implements WebMvcConfigurer {
@Override
public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
resolvers.add(new CustomExceptionHandlerResolver());
}
}
|
使用 RestControllerAdvice/ControllerAdvice 和 ExceptionHandler 处理异常
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| @RestControllerAdvice
@ControllerAdvice
public class CustomControllerExceptionResolver {
@ExceptionHandler({NullPointerException.class})
@ResponseBody
public ResponseEntity<?> handlerNullPointerException(HttpServletRequest request, Throwable throwable) {
CustomResponseContent responseContent = CustomResponseContent.builder()
.code(500)
.status("fail")
.message("空指针异常")
.build();
return new ResponseEntity<>(responseContent, HttpStatus.INTERNAL_SERVER_ERROR);
}
@ExceptionHandler({IllegalArgumentException.class})
@ResponseBody
public ResponseEntity<?> handlerIllegalArgumentException(HttpServletRequest request, Throwable throwable) {
CustomResponseContent responseContent = CustomResponseContent.builder()
.code(400)
.status("fail")
.message("参数错误")
.build();
return new ResponseEntity<>(responseContent, HttpStatus.BAD_REQUEST);
}
@ExceptionHandler({MethodArgumentNotValidException.class})
@ResponseBody
public ResponseEntity<?> handlerMethodArgumentNotValidException(HttpServletRequest request, MethodArgumentNotValidException e) {
String errorMessage = e.getBindingResult()
.getAllErrors()
.stream()
.map(f -> ((FieldError) f).getField() + ":" + f.getDefaultMessage())
.collect(Collectors.joining(";"));
CustomResponseContent responseContent = CustomResponseContent.builder()
.code(400)
.status("fail")
.message(errorMessage)
.build();
return new ResponseEntity<>(responseContent, HttpStatus.BAD_REQUEST);
}
@ExceptionHandler({Exception.class})
@ResponseBody
public ResponseEntity<?> handlerException(HttpServletRequest request, Throwable throwable) {
CustomResponseContent responseContent = CustomResponseContent.builder()
.code(500)
.status("fail")
.message(throwable.getMessage())
.build();
return new ResponseEntity<>(responseContent, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
|
403/404… 等错误
添加了上述的异常处理后，还有一部分异常无法处理，如404 错误，这是因为这些错误的异常处理并不经过异常处理器，而是被转发到 /error的路径下，默认由org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController处理，所以，继承org.springframework.boot.autoconfigure.web.servlet.error.AbstractErrorController并添加相应实现即可自定义处理该异常返回 JSON 数据
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| @Controller
@RequestMapping("/error")
public class CustomNoHandlerExceptionResolver extends AbstractErrorController {
public CustomNoHandlerExceptionResolver(ErrorAttributes errorAttributes) {
super(errorAttributes);
}
@Override
public String getErrorPath() {
return null;
}
@RequestMapping
@ResponseBody
public ResponseEntity<?> error(HttpServletRequest request, HttpServletResponse response) {
Optional<String> originRequestUri = Optional.ofNullable((String) request.getAttribute("javax.servlet.error.request_uri"));
String reasonPhrase = HttpStatus.valueOf(response.getStatus()).getReasonPhrase();
CustomResponseContent responseContent = CustomResponseContent.builder()
.code(response.getStatus())
.status("fail")
.message(originRequestUri.orElse("/error") + ":" + reasonPhrase)
.build();
return new ResponseEntity<>(responseContent, HttpStatus.valueOf(response.getStatus()));
}
}
|
转载自：https://blog.csdn.net/u013360850/article/details/93101903