一：定义异常类：

public class BusinessException extends RuntimeException {
    private Integer code;

    public BusinessException() {
        super();
    }

    public BusinessException(Integer code, String message) {
        super(message);
        this.code = code;
    }

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

    public BusinessException(String message, Throwable cause) {
        super(message, cause);
    }

    public BusinessException(Throwable cause) {
        super(cause);
    }
    public BusinessException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }
}
二：Servic 层或者dao层抛出异常：

三：捕获异常：

（1）全局捕获异常

（2）controlle进行捕获异常