java常用函数

十六进制字符串转换为整型：int sum = Integer.parseInt(this.getLoadMoney(), 16) / 100;

十进制字符串转换为长整型：long balance = (Long.parseLong(this.getBalance(), 10))/100; 

/**
  * 产生随机数
  * @return
  */
 public String rand() {

  return Integer.toHexString(new  Random().nextInt());

 }

/**
  * 格式化date
  * @param value
  * @return
  */
 public String date(Date value) {

  return new SimpleDateFormat("yyMMdd").format(value);
 }

 /**
  * 格式化time
  * @param value
  * @return
  */
 public String time(Date value) {

  return new SimpleDateFormat("HHmmss").format(value);

 }

//pPara字符串格式化为pDigit字节长度字符串

public static String trimPara(String pPara, int pDigit) {
  if (pPara.length() > pDigit) {
   pPara = pPara.substring(pPara.length() - pDigit);
  } else if (pPara.length() < pDigit) {
   int i = 0;
   int pLength = pPara.length();
   while ((i + pLength) < pDigit) {
    pPara = "0" + pPara;
    i++;
   }
  }
  return pPara;
 }

/**
     * 十六进制转字符串
     * @param hexString 十六进制字符串
     * @param encodeType 编码类型4：Unicode，2：普通编码
     * @return 字符串
     */
    public static String hexStringToString(String hexString, int encodeType) {
        String result = "";
        int max = hexString.length() / encodeType;
        for (int i = 0; i < max; i++) {
            char c = (char) DigitalConvert.hexStringToAlgorism(hexString.
                substring(i * encodeType, (i + 1) * encodeType));
            result += c;
        }
        return result;
    }

    /**
     * 十六进制字符串转byte
     * @param hex 十六进制字符串
     * @return byte数组
     */
    public static byte[] hexStringToByte(String hex) {
        int max = hex.length() / 2;
        byte[] bytes = new byte[max];
        String binarys = DigitalConvert.hexStringToBinary(hex);
        for (int i = 0; i < max; i++) {
            bytes[i] = (byte) DigitalConvert.binaryToAlgorism(binarys.substring(
                i * 8 + 1,
                (i + 1) * 8));
            if (binarys.charAt(8 * i) == '1') {
                bytes[i] = (byte) (0 - bytes[i]);
            }
        }
        return bytes;
    }

    /**
     * 十六进制字符串装十进制
     * @param hex 十六进制字符串
     * @return 十进制数值
     */
    public static int hexStringToAlgorism(String hex) {
        hex = hex.toUpperCase();
        int max = hex.length();
        int result = 0;
        for (int i = max; i > 0; i--) {
            char c = hex.charAt(i - 1);
            int algorism = 0;
            if (c >= '0' && c <= '9') {
                algorism = c - '0';
            }
            else {
                algorism = c - 55;
            }
            result += Math.pow(16, max - i) * algorism;
        }
        return result;
    }

    /**
     * 二进制转十进制
     * @param binary 二进制字符串
     * @return 十进制数值
     */
    public static int binaryToAlgorism(String binary) {
        int max = binary.length();
        int result = 0;
        for (int i = max; i > 0; i--) {
            char c = binary.charAt(i - 1);
            int algorism = c - '0';
            result += Math.pow(2, max - i) * algorism;
        }
        return result;
    }

    /**
     * 十六转二进制
     * @param hex 十六进制字符串
     * @return 二进制字符串
     */
    public static String hexStringToBinary(String hex) {
        hex = hex.toUpperCase();
        String result = "";
        int max = hex.length();
        for (int i = 0; i < max; i++) {
            char c = hex.charAt(i);
            switch (c) {
                case '0':
                    result += "0000";
                    break;
                case '1':
                    result += "0001";
                    break;
                case '2':
                    result += "0010";
                    break;
                case '3':
                    result += "0011";
                    break;
                case '4':
                    result += "0100";
                    break;
                case '5':
                    result += "0101";
                    break;
                case '6':
                    result += "0110";
                    break;
                case '7':
                    result += "0111";
                    break;
                case '8':
                    result += "1000";
                    break;
                case '9':
                    result += "1001";
                    break;
                case 'A':
                    result += "1010";
                    break;
                case 'B':
                    result += "1011";
                    break;
                case 'C':
                    result += "1100";
                    break;
                case 'D':
                    result += "1101";
                    break;
                case 'E':
                    result += "1110";
                    break;
                case 'F':
                    result += "1111";
                    break;
            }
        }
        return result;
    }