char int byte

public static void main(String[] args) {
//String t = encode("15013020645");
byte[] bs = hexToBytes("683133393838383833333333010000B516");
String tt = hexByteToStr(bs);
System.out.println(tt);
}

public static String hexToStr(String hexValue) {
    String hex = "0123456789ABCDEF";
    char[] hexs = hexValue.toCharArray();
    byte[] bytes = new byte[hexValue.length() / 2];
    int n;
    for (int i = 0; i < bytes.length; i++) {
        n = hex.indexOf(hexs[2 * i]) * 16;
        n += hex.indexOf(hexs[2 * i + 1]);
        bytes[i] = (byte) (n & 0xff);
    }
    return new String(bytes);
}

public static byte[] hexToBytes(String hexValue) {   
String hex = "0123456789ABCDEF";
if (null == hexValue || "".equals(hexValue.trim())) {
return new byte[0];
}
hexValue = hexValue.toUpperCase();
int length = hexValue.length() / 2;
char[] hexChars = hexValue.toCharArray();
byte[] bs = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
bs[i] = (byte) (hex.indexOf(hexChars[pos]) << 4 | hex.indexOf(hexChars[pos + 1]));
}
return bs;   
  }   


public static String hexByteToStr(byte[] bs){
return new String(bs);
}








public static String strToHex(String value) {
String hex = "0123456789ABCDEF";
byte[] bytes = value.getBytes();
StringBuilder builder = new StringBuilder(bytes.length * 2);
for (int i = 0; i < bytes.length; i++) {
builder.append(hex.charAt((bytes[i] & 0xf0) >> 4));
builder.append(hex.charAt((bytes[i] & 0x0f) >> 0));
}
return builder.toString();
}



public static char byteToChar(byte[] b) {
int s = 0;
if (b[0] > 0)
s += b[0];
else
s += 256 + b[0];
s *= 256;
if (b[1] > 0)
s += b[1];
else
s += 256 + b[1];
char ch = (char) s;
return ch;
}

public static byte[] charToByte(char ch){
int temp = (int) ch;
byte[] b = new byte[2];
for (int i = b.length - 1; i > -1; i--) {
b[i] = new Integer(temp & 0xff).byteValue();// 将最高位保存在最低位
temp = temp >> 8; // 向右移8位
}
return b;
}

//字符到字节转换
public static int byteToInt(byte[] b) {
int s = 0;
for (int i = 0; i < 3; i++) {
if (b[i] >= 0)
s = s + b[i];
else
s = s + 256 + b[i];
s = s * 256;
}
if (b[3] >= 0)// 最后一个之所以不乘，是因为可能会溢出
s = s + b[3];
else
s = s + 256 + b[3];
return s;
}


public static int byteToInt1(byte[] byteVal) {
    int result = 0;
for (int i = 0; i < byteVal.length; i++) {
int tmpVal = (byteVal[i] << (8 * (3 - i)));
switch (i) {
case 0:
tmpVal = tmpVal & 0xFF000000;
break;
case 1:
tmpVal = tmpVal & 0x00FF0000;
break;
case 2:
tmpVal = tmpVal & 0x0000FF00;
break;
case 3:
tmpVal = tmpVal & 0x000000FF;
break;
}
result = result | tmpVal;
}
   return result;
}