SpringBoot 实现全局异常处理的示例代码

import lombok.SneakyThrows;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import javax.servlet.http.HttpServletRequest;
import java.util.Optional;

/**
 * 全局异常处理器
 */
@RestControllerAdvice
public class GlobalExceptionHandler {

    public final Logger logger = LoggerFactory.getLogger(this.getClass());

    /**
     * 拦截参数验证异常
     */
    @SneakyThrows
    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    public AjaxResult validExceptionHandler(HttpServletRequest request, MethodArgumentNotValidException ex) {
        BindingResult bindingResult = ex.getBindingResult();
        FieldError firstFieldError = CollectionUtil.getFirst(bindingResult.getFieldErrors());
        String exceptionStr = Optional.ofNullable(firstFieldError)
                .map(FieldError::getDefaultMessage)
                .orElse(StrUtil.EMPTY);
        logger.error("[{}] {} [ex] {}", request.getMethod(), getUrl(request), exceptionStr);
        return AjaxResult.error(exceptionStr);
    }

    /**
     * 拦截业务异常
     * BusinessServiceException 是一个自定义异常，以你们项目中的自定义异常为准，如果没有可以不写
     */
    @ExceptionHandler(value = {BusinessServiceException.class})
    public AjaxResult handleBusinessException(HttpServletRequest request, BusinessServiceException ex){
        String exceptionStr = ex.getMessage();
        logger.error("[{}] {} [ex] {}", request.getMethod(), getUrl(request), exceptionStr);
        return AjaxResult.error(exceptionStr);
    }

    /**
     * 拦截未捕获异常
     */
    @ExceptionHandler(Throwable.class)
    public AjaxResult defaultErrorHandler(HttpServletRequest request, Throwable throwable) {
        logger.error("[{}] {} ", request.getMethod(), getUrl(request), throwable);
        return AjaxResult.error(throwable.getMessage());
    }

    private String getUrl(HttpServletRequest request) {
        if (StringUtils.isEmpty(request.getQueryString())) {
            return request.getRequestURL().toString();
        }
        return request.getRequestURL().toString() + "?" + request.getQueryString();
    }
}

import lombok.Data;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

@Data
public class UserEntity {

    @NotNull(message = "用户ID不能为空")
    private Long userId;

    @NotNull(message = "用户名不能为空")
    @Size(min = 2, max = 30, message = "用户名长度必须在2到30个字符之间")
    private String username;
    
}

// 注意，这个方法我们并没有采取任何 try catch 操作
@PostMapping("/test")
public AjaxResult Test(HttpServletRequest request, @RequestBody @Valid UserEntity userEntity) {
        Map<String,Object> model = new HashMap<String,Object>();
        String planCode = request.getParameter("planCode");
        String planDefineId = request.getParameter("planDefineId");
        if (StringUtils.isBlank(planDefineId) || StringUtils.isBlank(planCode)) {
            throw new BusinessServiceException("参数不可以为空！");
        }
        // 获取信息
        String planName = retailProductCommon.getproductName(planCode, planDefineId);
        model.put("planName", planName);
        return AjaxResult.success(model);
}