//駝峰轉(zhuǎn)下劃線
String ans = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, "helloWorld");
System.out.println(ans);
//下劃線轉(zhuǎn)駝峰
String ans2 = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, "hello_world");
System.out.println(ans2);

//排序:駝峰轉(zhuǎn)下劃線
String sortname = query.getSortname();
if (StringUtils.isNotEmpty(sortname)) {
    try {
        BrandStoreSkuInvSalRateWeekDTO.class.getField(sortname);
        sortname = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, sortname);
        query.setSortname(sortname);
    } catch (NoSuchFieldException e) {
        log.error("排序字段不存在,排序字段為{}", sortname);
        query.setSortname(null);
    }
}

String ans = StrUtil.toCamelCase("hello_world");
System.out.println(ans);
String ans2 = StrUtil.toUnderlineCase("helloWorld");
System.out.println(ans2);

public class ColumnUtil {
    private static Pattern humpPattern = Pattern.compile("[A-Z]");
    private static Pattern linePattern = Pattern.compile("_(\\w)");
    /**
     * 駝峰轉(zhuǎn)下劃線
     * @param str
     * @return
     */
    public static String humpToLine(String str) {
        Matcher matcher = humpPattern.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }
    /**
     * 下劃線轉(zhuǎn)駝峰
     * @param str
     * @return
     */
    public static String lineToHump(String str) {
        str = str.toLowerCase();
        Matcher matcher = linePattern.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, matcher.group(1).toUpperCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }
}

mybatis-plus:
  configuration:
    map-underscore-to-camel-case: true