zZ Java中String和Byte[]之间的那些事

Java中String和byte[]数组之间的转换很多，转载一些代码作为日后使用参考。

转载自：[http://hongyiqiye.iteye.com/blog/1028687]

public static String stringToHexString(String strPart) {
String hexString = "";
for (int i = 0; i < strPart.length(); i++) {
int ch = (int) strPart.charAt(i);
String strHex = Integer.toHexString(ch);
hexString = hexString + strHex;
}
return hexString;
}

private static String hexString="0123456789ABCDEF";

public static String encode(String str)
{
// 根据默认编码获取字节数组
byte[] bytes=str.getBytes();
StringBuilder sb=new StringBuilder(bytes.length*2);
// 将字节数组中每个字节拆解成2位16进制整数
for(int i=0;i<bytes.length;i++)
{
sb.append(hexString.charAt((bytes[i]&0xf0)>>4));
sb.append(hexString.charAt((bytes[i]&0x0f)>>0));
}
return sb.toString();
}

public static String decode(String bytes)
{
ByteArrayOutputStream baos=new ByteArrayOutputStream(bytes.length()/2);
// 将每2位16进制整数组装成一个字节
for(int i=0;i<bytes.length();i+=2)
baos.write((hexString.indexOf(bytes.charAt(i))<<4 |hexString.indexOf(bytes.charAt(i+1))));
return new String(baos.toByteArray());
}

private 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 byte[] HexString2Bytes(String src)
{
byte[] ret = new byte[6];
byte[] tmp = src.getBytes();
for(int i=0; i<6; ++i )
{
ret[i] = uniteBytes(tmp[i*2], tmp[i*2+1]);
}
return ret;
}

====================================================================

java 格式化输出十六进制数
// 以16进制输出文件内容, 每16个数换行一次
for(int i = 0; i < nLen; i++)
{
if(i % 16 == 0)
System.out.println();
String strHex = new String();
strHex = Integer.toHexString(chBuf[i]).toUpperCase();
if(strHex.length() > 3)
System.out.print(strHex.substring(6));
else
if(strHex.length() < 2)
System.out.print("0" + strHex);
else
System.out.print(strHex);

System.out.print(" ");
}
输出结果
-----------------------------------------------------------------------
FF D8 FF E0 00 10 4A 46 49 46 00 01 01 00 00 01
00 01 00 00 FF E1 00 E6 45 78 69 66 00 00 49 49
2A 00 08 00 00 00 05 00 12 01 03 00 01 00 00 00
01 00 00 00 31 01 02 00 1C 00 00 00 4A 00 00 00
32 01 02 00 14 00 00 00 66 00 00 00 13 02 03 00
01 00 00 00 01 00 00 00 69 87 04 00 01 00 00 00
7A 00 00 00
=================================
当我们把string字符串转成byte[]后，要再转成string 通过String.valueof()是实现不了的，只能new string(byte [])。