util.java

分页类,包括中文和英文及其他语言种类,便于二次开发及商业开发,

    for (i = 0; i < bytes.length; i++) {
      if ( ( (int) bytes[i] & 0xff) < 0x10) {
        buf.append("0");
      }
      buf.append(Long.toString( (int) bytes[i] & 0xff, 16));
    }
    return buf.toString().toUpperCase();
  }

  /**
   * Turns a hex encoded string into a byte array. It is specifically meant
   * to "reverse" the toHex(byte[]) method.
   *
   * @param hex a hex encoded String to transform into a byte array.
   * @return a byte array representing the hex String[
   */
  public static final byte[] decodeHex(String hex) {
    char[] chars = hex.toCharArray();
    byte[] bytes = new byte[chars.length / 2];
    int byteCount = 0;
    for (int i = 0; i < chars.length; i += 2) {
      byte newByte = 0x00;
      newByte |= hexCharToByte(chars[i]);
      newByte <<= 4;
      newByte |= hexCharToByte(chars[i + 1]);
      bytes[byteCount] = newByte;
      byteCount++;
    }
    return bytes;
  }

  /**
   * Returns the the byte value of a hexadecmical char (0-f). It's assumed
   * that the hexidecimal chars are lower case as appropriate.
   *
   * @param ch a hexedicmal character (0-f)
   * @return the byte value of the character (0x00-0x0F)
   */
  private static final byte hexCharToByte(char ch) {
    switch (ch) {
      case '0':
        return 0x00;
      case '1':
        return 0x01;
      case '2':
        return 0x02;
      case '3':
        return 0x03;
      case '4':
        return 0x04;
      case '5':
        return 0x05;
      case '6':
        return 0x06;
      case '7':
        return 0x07;
      case '8':
        return 0x08;
      case '9':
        return 0x09;
      case 'a':
        return 0x0A;
      case 'b':
        return 0x0B;
      case 'c':
        return 0x0C;
      case 'd':
        return 0x0D;
      case 'e':
        return 0x0E;
      case 'f':
        return 0x0F;
    }
    return 0x00;
  }

  /**
   * Converts a line of text into an array of lower case words using a
   * BreakIterator.wordInstance(). <p>
   *
   * This method is under the Jive Open Source Software License and was
   * written by Mark Imbriaco.
   *
   * @param text a String of text to convert into an array of words
   * @return text broken up into an array of words.
   */
  public static final String[] toLowerCaseWordArray(String text) {
    if (text == null || text.length() == 0) {
      return new String[0];
    }

    ArrayList wordList = new ArrayList();
    BreakIterator boundary = BreakIterator.getWordInstance();
    boundary.setText(text);
    int start = 0;

    for (int end = boundary.next(); end != BreakIterator.DONE;
         start = end, end = boundary.next()) {
      String tmp = text.substring(start, end).trim();
      // Remove characters that are not needed.
      tmp = replace(tmp, "+", "");
      tmp = replace(tmp, "/", "");
      tmp = replace(tmp, "\\", "");
      tmp = replace(tmp, "#", "");
      tmp = replace(tmp, "*", "");
      tmp = replace(tmp, ")", "");
      tmp = replace(tmp, "(", "");
      tmp = replace(tmp, "&", "");
      if (tmp.length() > 0) {
        wordList.add(tmp);
      }
    }
    return (String[]) wordList.toArray(new String[wordList.size()]);
  }

  /**
   * Pseudo-random number generator object for use with randomString().
   * The Random class is not considered to be cryptographically secure, so
   * only use these random Strings for low to medium security applications.
   */
  private static Random randGen = new Random();

  /**
   * Array of numbers and letters of mixed case. Numbers appear in the list
   * twice so that there is a more equal chance that a number will be picked.
   * We can use the array to get a random number or letter by picking a random
   * array index.
   */
  private static char[] numbersAndLetters = (
      "0123456789abcdefghijklmnopqrstuvwxyz" +
      "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();

  /**
   * Returns a random String of numbers and letters (lower and upper case)
   * of the specified length. The method uses the Random class that is
   * built-in to Java which is suitable for low to medium grade security uses.
   * This means that the output is only pseudo random, i.e., each number is
   * mathematically generated so is not truly random.<p>
   *
   * The specified length must be at least one. If not, the method will return
   * null.
   *
   * @param length the desired length of the random String to return.
   * @return a random String of numbers and letters of the specified length.
   */
  public static final String randomString(int length) {
    if (length < 1) {
      return null;
    }
    // Create a char buffer to put random letters and numbers in.
    char[] randBuffer = new char[length];
    for (int i = 0; i < randBuffer.length; i++) {
      randBuffer[i] = numbersAndLetters[randGen.nextInt(71)];
    }
    return new String(randBuffer);
  }

  /**
   * Intelligently chops a String at a word boundary (whitespace) that occurs
   * at the specified index in the argument or before. However, if there is a
   * newline character before <code>length</code>, the String will be chopped
   * there. If no newline or whitespace is found in <code>string</code> up to
   * the index <code>length</code>, the String will chopped at <code>length</code>.
   * <p>
   * For example, chopAtWord("This is a nice String", 10) will return
   * "This is a" which is the first word boundary less than or equal to 10
   * characters into the original String.
   *
   * @param string the String to chop.
   * @param length the index in <code>string</code> to start looking for a
   *       whitespace boundary at.
   * @return a substring of <code>string</code> whose length is less than or
   *       equal to <code>length</code>, and that is chopped at whitespace.
   */
  public static final String chopAtWord(String string, int length) {
    if (string == null) {
      return string;
    }

    char[] charArray = string.toCharArray();
    int sLength = string.length();
    if (length < sLength) {
      sLength = length;
    }

    // First check if there is a newline character before length; if so,
    // chop word there.
    for (int i = 0; i < sLength - 1; i++) {
      // Windows
      if (charArray[i] == '\r' && charArray[i + 1] == '\n') {
        return string.substring(0, i + 1);
      }
      // Unix
      else if (charArray[i] == '\n') {
        return string.substring(0, i);
      }
    }
    // Also check boundary case of Unix newline
    if (charArray[sLength - 1] == '\n') {
      return string.substring(0, sLength - 1);
    }

    // Done checking for newline, now see if the total string is less than
    // the specified chop point.
    if (string.length() < length) {
      return string;
    }

    // No newline, so chop at the first whitespace.
    for (int i = length - 1; i > 0; i--) {
      if (charArray[i] == ' ') {
        return string.substring(0, i).trim();
      }
    }

    // Did not find word boundary so return original String chopped at
    // specified length.
    return string.substring(0, length);
  }

  /**
   * Escapes all necessary characters in the String so that it can be used
   * in an XML doc.
   *
   * @param string the string to escape.
   * @return the string with appropriate characters escaped.
   */
  public static final String escapeForXML(String string) {
    if (string == null) {
      return null;
    }
    char ch;
    int i = 0;
    int last = 0;
    char[] input = string.toCharArray();
    int len = input.length;
    StringBuffer out = new StringBuffer( (int) (len * 1.3));
    for (; i < len; i++) {
      ch = input[i];
      if (ch > '>') {
        continue;
      }
      else if (ch == '<') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(LT_ENCODE);
      }
      else if (ch == '&') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(AMP_ENCODE);
      }
      else if (ch == '"') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(QUOTE_ENCODE);
      }
    }
    if (last == 0) {
      return string;
    }
    if (i > last) {
      out.append(input, last, i - last);
    }
    return out.toString();
  }

  public static final String escapeForSpecial(String string) {
    if (string == null) {
      return null;
    }
    char ch;
    int i = 0;
    int last = 0;
    char[] input = string.toCharArray();
    int len = input.length;
    StringBuffer out = new StringBuffer( (int) (len * 1.3));
    for (; i < len; i++) {
      ch = input[i];
      if (ch > '>') {
        continue;
      }
      else if (ch == '<') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(LT_ENCODE);
      }
      else if (ch == '&') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(AMP_ENCODE);
      }
      else if (ch == '"') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(QUOTE_ENCODE);
      }
      else if (ch == '>') {
        if (i > last) {
          out.append(input, last, i - last);
        }
        last = i + 1;
        out.append(GT_ENCODE);
      }
    }
    if (last == 0) {
      return string;
    }
    if (i > last) {
      out.append(input, last, i - last);
    }
    return out.toString();
  }

  /**
   * Unescapes the String by converting XML escape sequences back into normal
   * characters.
   *
   * @param string the string to unescape.
   * @return the string with appropriate characters unescaped.
   */
  public static final String unescapeFromXML(String string) {
    string = replace(string, "&lt;", "<");
    string = replace(string, "&gt;", ">");
    string = replace(string, "&quot;", "\"");
    return replace(string, "&amp;", "&");
  }

  private static final char[] zeroArray = "0000000000000000".toCharArray();

  /**
   * Pads the supplied String with 0's to the specified length and returns
   * the result as a new String. For example, if the initial String is
   * "9999" and the desired length is 8, the result would be "00009999".
   * This type of padding is useful for creating numerical values that need
   * to be stored and sorted as character data. Note: the current
   * implementation of this method allows for a maximum <tt>length</tt> of
   * 16.
   *
   * @param string the original String to pad.
   * @param length the desired length of the new padded String.
   * @return a new String padded with the required number of 0's.
   */
  public static final String zeroPadString(String string, int length) {
    if (string == null || string.length() > length) {
      return string;
    }
    StringBuffer buf = new StringBuffer(length);
    buf.append(zeroArray, 0, length - string.length()).append(string);
    return buf.toString();
  }

  /**
   * Formats a Date as a fifteen character long String made up of the Date's
   * padded millisecond value.
   *
   * @return a Date encoded as a String.
   */
  public static final String dateToMillis(Date date) {
    return zeroPadString(Long.toString(date.getTime()), 15);
  }

  /**
   * Formats a Date as a fifteen character long String made up of the Date's
   * padded millisecond value.
   *
   * @return a Date encoded as a String.
   */