private static int mask(StringBuilder builder, char maskChar, int startPos, int endPos) {
        final String masked = "" + maskChar + maskChar + maskChar + maskChar + maskChar + maskChar;
        builder.replace(startPos, endPos, masked);
        return startPos + 6;
    }
replace sensitive message with six specified maskChar

@param builder raw data
@param maskChar specified character for replace sensitive data
@param startPos the start position of sensitive data
@param endPos the end position of sensitive data
@return the new end position of replaced data
inlong-common/src/main/java/org/apache/inlong/common/util/MaskDataUtils.java