Android开发中遇到的字符串、十六进制和Byte转换，及十六进制校验等函数集

import java.io.UnsupportedEncodingException;

public class EncodingConversionTools {

/**
* 字符串转换成十六进制字符串（转GBK编码）
* @param String str 待转换的ASCII字符串
* @return String 如: [616C6B]
*/
public static String str2HexStr(String str)
{

char[] chars = "0123456789ABCDEF".toCharArray();
StringBuilder sb = new StringBuilder("");
byte[] bs = null;
try {
bs = str.getBytes("GBK");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int bit;

for (int i = 0; i < bs.length; i++)
{
bit = (bs[i] & 0x0f0) >> 4;
sb.append(chars[bit]);
bit = bs[i] & 0x0f;
sb.append(chars[bit]);
}
return sb.toString().trim();
}

/**
* 生成16进制累加和校验码
* @param data
* 除去校验位的数据
* @return
*/
public static String makeChecksum(String data) {
int total = 0;
int len = data.length();
int num = 0;
while (num < len) {
String s = data.substring(num, num + 2);
total += Integer.parseInt(s, 16);
num = num + 2;
}
/**
* 用65535求余最大是65534，即16进制的FFFF
*/
int mod = total % 65535;
String hex = Integer.toHexString(mod);
len = hex.length();
// 如果不够校验位的长度，补0
switch (len) {
case 1:
hex = "000" + hex;
break;
case 2:
hex = "00" + hex;
break;
case 3:
hex = "0" + hex;
break;
default:
break;
}
return hex;
}

public static byte[] HexString2Bytes(String src) {
int lenth = src.length() / 2;
byte[] ret = new byte[lenth];
byte[] tmp = src.getBytes();
for (int i = 0; i < lenth; i++) {
ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);
}
return ret;
}

public static byte uniteBytes(byte src0, byte src1) {
byte _b0 = Byte.decode("0x" + new String(new byte[] { src0 }))
.byteValue();
_b0 = (byte) (_b0 << 4);
byte _b1 = Byte.decode("0x" + new String(new byte[] { src1 }))
.byteValue();
byte ret = (byte) (_b0 ^ _b1);
return ret;
}

public static String getHexStr(String str) {
String rtn = "";
String hexStr = "0123456789ABCDEF";

str = str.toUpperCase();
for (int i = 0; i < str.length(); i++) {
if (hexStr.indexOf(str.charAt(i)) != -1) {
rtn = rtn + str.charAt(i);
}
}
return rtn;
}

/**
* bytes转换成十六进制字符串
* @param byte[] b byte数组
* @return String 每个Byte值之间空格分隔
*/
public static String byte2HexStr(byte[] b) {
String stmp = "";
StringBuilder sb = new StringBuilder("");
for (int n = 0; n < b.length; n++) {
stmp = Integer.toHexString(b
& 0xFF);
sb.append((stmp.length() == 1) ? "0" + stmp : stmp);
sb.append(" ");
}
return sb.toString().toUpperCase().trim();
}
}