在SpringBoot中配置全局异常处理

@ControllerAdvice: 定义一个全局的异常处理类，同时也可以使用@RestControllerAdvice返回JSON格式。

@ControllerAdvice
public class GlobalExceptionHandler {
    //......
}

@ExceptionHandler: 统一的处理异常，可以自定义异常类型。
比如：定义 @ExceptionHandler({NullPointerException.class, BusinessException.class}) 来处理空指针异常和一个我们自定义的一个业务异常。

@ExceptionHandler({NullPointerException.class, BusinessException.class})
public Object businessHandler(HttpServletRequest request, BusinessException e) throws BusinessException {
      // ......
}

我们创建一个全局的异常处理类：GlobalExceptionHandler

import org.apache.log4j.Logger;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

/**
 * 异常全局处理类
 */
@ControllerAdvice
public class GlobalExceptionHandler {

    private Logger logger = Logger.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(Exception.class)
    public Object exceptionHandler(HttpServletRequest request, Exception e) throws Exception {
        logger.error(e);

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("url", request.getRequestURL());
        modelAndView.addObject("exception", e);
        modelAndView.setViewName("error");

        return modelAndView;

    }

    @ExceptionHandler(BusinessException.class)
    public Object businessHandler(HttpServletRequest request, BusinessException e) throws BusinessException {
        logger.error(e);

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("url", request.getRequestURL());
        modelAndView.addObject("exception", e);
        modelAndView.setViewName("business_error");

        return modelAndView;

    }

    /**
     * 判断是否为一个ajax请求
     * @param request
     * @return
     */
    public boolean isAjaxRequest(HttpServletRequest request) {
        String header = request.getHeader("X-Requested-With");
        boolean isAjax = "XMLHttpRequest".equals(header) ? true : false;
        return isAjax;
    }

}

接下来我们定义一个业务异常类：BusinessException，继承RuntimeException。

public class BusinessException extends RuntimeException {

    public BusinessException() {
        super();
    }

    public BusinessException(String message) {
        super(message);
    }

}