content: package org.dbsyncer.common.util;
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  public abstract class UnderlineToCamelUtils {
  
      /**
       * 下划线转驼峰法
       *
       * @param line       源字符串
       * @param smallCamel 大小驼峰,是否为小驼峰
       * @return 转换后的字符串
       */
      public static String underlineToCamel(String line, boolean smallCamel) {
          if (line == null || "".equals(line)) {
              return "";
          }
          StringBuffer sb = new StringBuffer();
          Pattern pattern = Pattern.compile("([A-Za-z\\d]+)(_)?");
          Matcher matcher = pattern.matcher(line);
          while (matcher.find()) {
              String word = matcher.group();
              sb.append(smallCamel && matcher.start() == 0 ? Character.toLowerCase(word.charAt(0)) : Character.toUpperCase(word.charAt(0)));
              int index = word.lastIndexOf('_');
              if (index > 0) {
                  sb.append(word.substring(1, index).toLowerCase());
              } else {
                  sb.append(word.substring(1).toLowerCase());
              }
          }
          return sb.toString();
      }
  
      /**
       * 驼峰法转下划线
       *
       * @param line 源字符串
       * @return 转换后的字符串
       */
      public static String camelToUnderline(String line) {
          if (line == null || "".equals(line)) {
              return "";
          }
          line = String.valueOf(line.charAt(0)).toUpperCase().concat(line.substring(1));
          StringBuffer sb = new StringBuffer();
          Pattern pattern = Pattern.compile("[A-Z]([a-z\\d]+)?");
          Matcher matcher = pattern.matcher(line);
          while (matcher.find()) {
              String word = matcher.group();
              sb.append(word.toUpperCase());
              sb.append(matcher.end() == line.length() ? "" : "_");
          }
          return sb.toString();
      }
  }