Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
com.xiaoleilu.hutool.lang.Base64 Maven / Gradle / Ivy
package com.xiaoleilu.hutool.lang;
import java.nio.charset.Charset;
import com.xiaoleilu.hutool.util.CharsetUtil;
import com.xiaoleilu.hutool.util.StrUtil;
/**
* Base64工具类，提供Base64的编码和解码方案true，则每76个字符一个换行符，否则在一行显示
*
* @param arr 被编码的数组
* @param isMultiLine 在76个char之后是CRLF还是EOF
* @param isUrlSafe 是否使用URL安全字符，一般为false
* @return 编码后的bytes
*/
public static byte[] encode(byte[] arr, boolean isMultiLine, boolean isUrlSafe) {
if(null == arr){
return null;
}
int len = arr.length;
if (len == 0) {
return new byte[0];
}
int evenlen = (len / 3) * 3;
int cnt = ((len - 1) / 3 + 1) << 2;
int destlen = cnt + (isMultiLine ? (cnt - 1) / 76 << 1 : 0);
byte[] dest = new byte[destlen];
byte[] encodeTable = isUrlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
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++] = encodeTable[(i >>> 18) & 0x3f];
dest[d++] = encodeTable[(i >>> 12) & 0x3f];
dest[d++] = encodeTable[(i >>> 6) & 0x3f];
dest[d++] = encodeTable[i & 0x3f];
if (isMultiLine && ++cc == 19 && d < destlen - 2) {
dest[d++] = '\r';
dest[d++] = '\n';
cc = 0;
}
}
int left = len - evenlen;//剩余位数
if (left > 0) {
int i = ((arr[evenlen] & 0xff) << 10) | (left == 2 ? ((arr[len - 1] & 0xff) << 2) : 0);
dest[destlen - 4] = encodeTable[i >> 12];
dest[destlen - 3] = encodeTable[(i >>> 6) & 0x3f];
if(isUrlSafe){
//在URL Safe模式下，=为URL中的关键字符，不需要补充。空余的byte位要去掉。
int urlSafeLen = destlen - 2;
if(2 == left){
dest[destlen - 2] = encodeTable[i & 0x3f];
urlSafeLen += 1;
}
byte[] urlSafeDest = new byte[urlSafeLen];
System.arraycopy(dest, 0, urlSafeDest, 0, urlSafeLen);
return urlSafeDest;
}else{
dest[destlen - 2] = left == 2 ? encodeTable[i & 0x3f] : (byte) '=';
dest[destlen - 1] = '=';
}
}
return dest;
}
// -------------------------------------------------------------------- decode
/**
* base64解码
*
* @param source 被解码的base64字符串
* @return 被加密后的字符串
*/
public static String decodeStr(String source) {
return decodeStr(source, CharsetUtil.UTF_8);
}
/**
* base64解码
*
* @param source 被解码的base64字符串
* @param charset 字符集
* @return 被加密后的字符串
*/
public static String decodeStr(String source, String charset) {
return StrUtil.str(decode(source, charset), charset);
}
/**
* base64解码
*
* @param source 被解码的base64字符串
* @param charset 字符集
* @return 被加密后的字符串
*/
public static String decodeStr(String source, Charset charset) {
return StrUtil.str(decode(source, charset), charset);
}
/**
* base64解码
*
* @param source 被解码的base64字符串
* @return 被加密后的字符串
*/
public static byte[] decode(String source) {
return decode(source, CharsetUtil.UTF_8);
}
/**
* base64解码
*
* @param source 被解码的base64字符串
* @param charset 字符集
* @return 被加密后的字符串
*/
public static byte[] decode(String source, String charset) {
return decode(StrUtil.bytes(source, charset));
}
/**
* base64解码
*
* @param source 被解码的base64字符串
* @param charset 字符集
* @return 被加密后的字符串
*/
public static byte[] decode(String source, Charset charset) {
return decode(StrUtil.bytes(source, charset));
}
/**
* 解码Base64，同时解码URL安全和非安全的base64编码
*
* @param arr byte数组
* @return 解码后的byte数组
*/
public static byte[] decode(byte[] arr) {
if(null == arr){
return null;
}
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];
// byte[] decodeTable = isUrlSafe ? URL_SAFE_DECODE_TABLE : STANDARD_DECODE_TABLE;
byte[] decodeTable = DECODE_TABLE;
int d = 0;
for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
int i = decodeTable[arr[sndx++]] << 18 | decodeTable[arr[sndx++]] << 12 | decodeTable[arr[sndx++]] << 6 | decodeTable[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 |= decodeTable[arr[sndx++]] << (18 - j * 6);
}
for (int r = 16; d < len; r -= 8) {
dest[d++] = (byte) (i >> r);
}
}
return dest;
}
}
