public class ConvertBytesToBase64 {
// 下面的代码转换byte数组到 Base64
private static char[] CharCode = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'
};
private static String ConvertByte3ToString(byte[] bytes){
String temp = new String("");
temp += CharCode[((bytes[0])>>>2)&0x3f];
temp += CharCode[((bytes[0]&0x03)<<4)|((bytes[1]>>>4)&0x0f)];
temp += CharCode[((bytes[1]&0x0f)<<2)|((bytes[2]>>>6)&0x03)];
temp += CharCode[bytes[2]&0x3f];
return temp;
}
private static String ConvertByte2ToString(byte[] bytes){
String temp = new String("");
temp += CharCode[((bytes[0])>>>2)&0x3f];
temp += CharCode[((bytes[0]&0x03)<<4)|((bytes[1]>>>4)&0x0f)];
temp += CharCode[((bytes[1]&0x0f)<<2)];
temp += '=';
return temp;
}
private static String ConvertByteToString(byte[] bytes){
String temp = new String("");
temp += CharCode[((bytes[0])>>>2)&0x3f];
temp += CharCode[((bytes[0]&0x03)<<4)];
temp += "==";
return temp;
}
public static String BytesToBase64String(byte[] buffer){
String reslut = new String("");
int length = buffer.length;
int index = 0;
for(index = 0;(index+3)<length;index+=3){
byte[] temp = {buffer[index],buffer[index+1],buffer[index+2]};
reslut += ConvertByte3ToString(temp);
}
if(length%3 == 1){
byte[] temp = {buffer[length-1]};
reslut += ConvertByteToString(temp);
}else if(length%3 == 2){
byte[] temp = {buffer[length-2],buffer[length-1]};
reslut += ConvertByte2ToString(temp);
}
return reslut;
}
}
相关文字说明:
http://my.oschina.net/u/251121/blog/65383