转自： 中国开源社区 最快的 Base64 编码/解码 算法
需要的jar包 commons-lang-2.5.jar
import java.util.Arrays;
import java.io.UnsupportedEncodingException;
import org.apache.commons.lang.time.StopWatch;
public class Base64 {
private static final char[] CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
.toCharArray();
private static final int[] INV = new int[256];
static {
Arrays.fill(INV, -1);
for (int i = 0, iS = CHARS.length; i < iS; i++) {
INV[CHARS[i]] = i;
}
INV['='] = 0;
}
/**
*
* Returns Base64 characters, a clone of used array.
*/
public static char[] getAlphabet() {
return CHARS.clone();
}
// ---------------------------------------------------------------- char[]
public static char[] encodeToChar(String s) {
try {
return encodeToChar(s.getBytes("UTF-8"), false);
} catch (UnsupportedEncodingException ignore) {
return null;
}
}
public static char[] encodeToChar(byte[] arr) {
return encodeToChar(arr, false);
}
/**
*
* Encodes a raw byte array into a BASE64 char[].
*/
public static char[] encodeToChar(byte[] arr, boolean lineSeparator) {
int len = arr != null ? arr.length : 0;
if (len == 0) {
return new char[0];
}
int evenlen = (len / 3) * 3;
int cnt = ((len - 1) / 3 + 1) << 2;
int destLen = cnt + (lineSeparator ? (cnt - 1) / 76 << 1 : 0);
char[] dest = new char[destLen];
for (int s = 0, d = 0, cc = 0; s < evenlen;) {
int i = (arr[s++] & 0xff) << 16 | (arr[s++] & 0xff) << 8
| (arr[s++] & 0xff);
dest[d++] = CHARS[(i >>> 18) & 0x3f];
dest[d++] = CHARS[(i >>> 12) & 0x3f];
dest[d++] = CHARS[(i >>> 6) & 0x3f];
dest[d++] = CHARS[i & 0x3f];
if (lineSeparator && (++cc == 19) && (d < (destLen - 2))) {
dest[d++] = '\r';
dest[d++] = '\n';
cc = 0;
}
}
int left = len - evenlen; // 0 - 2.
if (left > 0) {
int i = ((arr[evenlen] & 0xff) << 10)
| (left == 2 ? ((arr[len - 1] & 0xff) << 2) : 0);
dest[destLen - 4] = CHARS[i >> 12];
dest[destLen - 3] = CHARS[(i >>> 6) & 0x3f];
dest[destLen - 2] = left == 2 ? CHARS[i & 0x3f] : '=';
dest[destLen - 1] = '=';
}
return dest;
}
/**
*
* Decodes a BASE64 encoded char array.
*/
public byte[] decode(char[] arr) {
int length = arr.length;
if (length == 0) {
return new byte[0];
}
int sndx = 0, endx = length - 1;
int pad = arr[endx] == '=' ? (arr[endx - 1] == '=' ? 2 : 1) : 0;
int cnt = endx - sndx + 1;
int sepCnt = length > 76 ? (arr[76] == '\r' ? cnt / 78 : 0) << 1 : 0;
int len = ((cnt - sepCnt) * 6 >> 3) - pad;
byte[] dest = new byte[len];
int d = 0;
for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
int i = INV[arr[sndx++]] << 18 | INV[arr[sndx++]] << 12
| INV[arr[sndx++]] << 6 | INV[arr[sndx++]];
dest[d++] = (byte) (i >> 16);
dest[d++] = (byte) (i >> 8);
dest[d++] = (byte) i;
if (sepCnt > 0 && ++cc == 19) {
sndx += 2;
cc = 0;
}
}
if (d < len) {
int i = 0;
for (int j = 0; sndx <= endx - pad; j++) {
i |= INV[arr[sndx++]] << (18 - j * 6);
}
for (int r = 16; d < len; r -= 8) {
dest[d++] = (byte) (i >> r);
}
}
return dest;
}
// ---------------------------------------------------------------- byte
public static byte[] encodeToByte(String s) {
try {
return encodeToByte(s.getBytes("UTF-8"), false);
} catch (UnsupportedEncodingException ignore) {
return null;
}
}
public static byte[] encodeToByte(byte[] arr) {
return encodeToByte(arr, false);
}
/**
*
* Encodes a raw byte array into a BASE64 byte[].
*/
public static byte[] encodeToByte(byte[] arr, boolean lineSep) {
int len = arr != null ? arr.length : 0;
if (len == 0) {
return new byte[0];
}
int evenlen = (len / 3) * 3;
int cnt = ((len - 1) / 3 + 1) << 2;
int destlen = cnt + (lineSep ? (cnt - 1) / 76 << 1 : 0);
byte[] dest = new byte[destlen];
for (int s = 0, d = 0, cc = 0; s < evenlen;) {
int i = (arr[s++] & 0xff) << 16 | (arr[s++] & 0xff) << 8
| (arr[s++] & 0xff);
dest[d++] = (byte) CHARS[(i >>> 18) & 0x3f];
dest[d++] = (byte) CHARS[(i >>> 12) & 0x3f];
dest[d++] = (byte) CHARS[(i >>> 6) & 0x3f];
dest[d++] = (byte) CHARS[i & 0x3f];
if (lineSep && ++cc == 19 && d < destlen - 2) {
dest[d++] = '\r';
dest[d++] = '\n';
cc = 0;
}
}
int left = len - evenlen;
if (left > 0) {
int i = ((arr[evenlen] & 0xff) << 10)
| (left == 2 ? ((arr[len - 1] & 0xff) << 2) : 0);
dest[destlen - 4] = (byte) CHARS[i >> 12];
dest[destlen - 3] = (byte) CHARS[(i >>> 6) & 0x3f];
dest[destlen - 2] = left == 2 ? (byte) CHARS[i & 0x3f] : (byte) '=';
dest[destlen - 1] = '=';
}
return dest;
}
/**
*
* Decodes a BASE64 encoded byte array.
*/
public static byte[] decode(byte[] arr) {
int length = arr.length;
if (length == 0) {
return new byte[0];
}
int sndx = 0, endx = length - 1;
int pad = arr[endx] == '=' ? (arr[endx - 1] == '=' ? 2 : 1) : 0;
int cnt = endx - sndx + 1;
int sepCnt = length > 76 ? (arr[76] == '\r' ? cnt / 78 : 0) << 1 : 0;
int len = ((cnt - sepCnt) * 6 >> 3) - pad;
byte[] dest = new byte[len];
int d = 0;
for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
int i = INV[arr[sndx++]] << 18 | INV[arr[sndx++]] << 12
| INV[arr[sndx++]] << 6 | INV[arr[sndx++]];
dest[d++] = (byte) (i >> 16);
dest[d++] = (byte) (i >> 8);
dest[d++] = (byte) i;
if (sepCnt > 0 && ++cc == 19) {
sndx += 2;
cc = 0;
}
}
if (d < len) {
int i = 0;
for (int j = 0; sndx <= endx - pad; j++) {
i |= INV[arr[sndx++]] << (18 - j * 6);
}
for (int r = 16; d < len; r -= 8) {
dest[d++] = (byte) (i >> r);
}
}
return dest;
}
// ---------------------------------------------------------------- string
public static String encodeToString(String s) {
try {
return new String(encodeToChar(s.getBytes("UTF-8"), false));
} catch (UnsupportedEncodingException ignore) {
return null;
}
}
public static String decodeToString(String s) {
try {
return new String(decode(s), "UTF-8");
} catch (UnsupportedEncodingException ignore) {
return null;
}
}
public static String encodeToString(byte[] arr) {
return new String(encodeToChar(arr, false));
}
/**
*
* Encodes a raw byte array into a BASE64 String.
*/
public static String encodeToString(byte[] arr, boolean lineSep) {
return new String(encodeToChar(arr, lineSep));
}
/**
*
* Decodes a BASE64 encoded string.
*/
public static byte[] decode(String s) {
int length = s.length();
if (length == 0) {
return new byte[0];
}
int sndx = 0, endx = length - 1;
int pad = s.charAt(endx) == '=' ? (s.charAt(endx - 1) == '=' ? 2 : 1)
: 0;
int cnt = endx - sndx + 1;
int sepCnt = length > 76 ? (s.charAt(76) == '\r' ? cnt / 78 : 0) << 1
: 0;
int len = ((cnt - sepCnt) * 6 >> 3) - pad;
byte[] dest = new byte[len];
int d = 0;
for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
int i = INV[s.charAt(sndx++)] << 18 | INV[s.charAt(sndx++)] << 12
| INV[s.charAt(sndx++)] << 6 | INV[s.charAt(sndx++)];
dest[d++] = (byte) (i >> 16);
dest[d++] = (byte) (i >> 8);
dest[d++] = (byte) i;
if (sepCnt > 0 && ++cc == 19) {
sndx += 2;
cc = 0;
}
}
if (d < len) {
int i = 0;
for (int j = 0; sndx <= endx - pad; j++) {
i |= INV[s.charAt(sndx++)] << (18 - j * 6);
}
for (int r = 16; d < len; r -= 8) {
dest[d++] = (byte) (i >> r);
}
}
return dest;
}
public static void main(String[] args) {
StopWatch sw = new StopWatch();
sw.start();
String str = "！@#￥%……&*（）——+brown fox jumps 你好，我是谁，Hello，我dogThe quick brown fox jumps over the lazy dog";
for (int i = 0; i < 100000; i++) {
//Base64.encodeToByte(str);
Base64.encodeToString(str);
}
//System.out.println(Base64.encodeToString(str));
sw.stop();
System.out.println(sw.getTime() + "毫秒");
}
}