链接：https://pan.baidu.com/s/1zrA87rSYLA_A09hyZ9mieA 提取码：uh6r

import java.util.List;

public class ParentCategory { 
        
    private List<Category> children;

    public List<Category> getChildren() { 
        
        return children;
    }

    public void setChildren(List<Category> children) { 
        
        this.children = children;
    }
}

public class Category extends ParentCategory{ 
        

  private long id;
  private String name;
  private long parentId;
  private Integer level;
  private Integer showStatus;
  private Integer sortNumber;

  @Override
  public String toString() { 
        
    StringBuffer s = new StringBuffer();
    for (int i = 1; i < level; i++) { 
        
      s.append("\t");
    }
    return "\n"+s+"Category{" +
            "id=" + id +
            ", name='" + name + '\'' +
            ", parentId=" + parentId +
            ", level=" + level +
            ", showStatus=" + showStatus +
            ", sortNumber=" + sortNumber +
            ", \n\t-->children=" + getChildren() +
            '}';
  }

  public long getId() { 
        
    return id;
  }

  public void setId(long id) { 
        
    this.id = id;
  }

  public String getName() { 
        
    return name;
  }

  public void setName(String name) { 
        
    this.name = name;
  }

  public long getParentId() { 
        
    return parentId;
  }

  public void setParentId(long parentId) { 
        
    this.parentId = parentId;
  }

  public Integer getLevel() { 
        
    return level;
  }

  public void setLevel(Integer level) { 
        
    this.level = level;
  }

  public Integer getShowStatus() { 
        
    return showStatus;
  }

  public void setShowStatus(Integer showStatus) { 
        
    this.showStatus = showStatus;
  }

  public Integer getSortNumber() { 
        
    return sortNumber;
  }

  public void setSortNumber(Integer sortNumber) { 
        
    this.sortNumber = sortNumber;
  }
}

public class StringUtil { 
        
    /** * 驼峰转下划线 * @param camelCaseName 驼峰字符串 * @return 下划线字符串 */
    public static String underscoreName(String camelCaseName) { 
        
        StringBuffer result = new StringBuffer();
        if (camelCaseName != null && camelCaseName.length() > 0) { 
        
            result.append(camelCaseName.substring(0, 1).toLowerCase());
            //拿到第一字母，直接转小写
            for (int i = 1; i < camelCaseName.length(); i++) { 
        
                char ch = camelCaseName.charAt(i);
                //取第i个位置的字符
                if (Character.isUpperCase(ch)) { 
        //判断该字符是不是大写字母
                    result.append("_");//如果是大写，则拼接下划线
                    result.append(Character.toLowerCase(ch));
                    //将自己转为小写加入result
                } else { 
        
                    result.append(ch);
                }
            }
        }
        return result.toString();
    }
}