参考链接： java字符串之-getbytes()
..
/**
* Convert input string to UTF-8, copies into buffer (at given offset).
* Returns number of bytes in the string.
*
* Java's internal UTF8 conversion is very, very slow.
* This is, rather amazingly, 8x faster than the to-string method.
* Returns the number of bytes this translated into.
*/
public static int stringToUtf8(String s, byte[] buf, int offset) {
if (s == null) {
return 0;
}
int length = s.length();
int startOffset = offset;
for (int i = 0; i < length; i ) {
int c = s.charAt(i);
if (c < 0x80) {
buf[offset ] = (byte) c;
}
else if (c < 0x800) {
buf[offset ] = (byte)(0xc0 | ((c >> 6)));
buf[offset ] = (byte)(0x80 | (c & 0x3f));
}
else {
// Encountered a different encoding other than 2-byte UTF8. Let java handle it.
try {
byte[] value = s.getBytes("UTF8");
System.arraycopy(value, 0, buf, startOffset, value.length);
return value.length;
}
catch (UnsupportedEncodingException uee) {
throw new RuntimeException("UTF8 encoding is not supported.");
}
}
}
return offset - startOffset;
}
