code: private String getCharacterConjunction(String text1, String text2, int windowLength) {
          StringBuilder conjunction = new StringBuilder();
          StringBuilder target = new StringBuilder(text2);
          int len1 = text1.length();
          for (int i = 0; i < len1; i++) {
              char source = text1.charAt(i);
              boolean found = false;
              int start = Math.max(0, i - windowLength);
              int end = Math.min(i + windowLength, text2.length());
              for (int j = start; !found && j < end; j++) {
                  if (source == target.charAt(j)) {
                      found = true;
                      conjunction.append(source);
                      target.setCharAt(j,'*');
                  }
              }
          }
          return conjunction.toString();
      }
docs: 获取两段文本的共有字符即字符交集
  @param text1 文本1
  @param text2 文本2
  @param windowLength 字符交集窗口大小
  @return 字符交集