package com.opslab.util.encrypt; import com.opslab.util.CharsetUtil; import java.io.UnsupportedEncodingException; import java.util.Arrays; /** * Base64的编码和解码 */ public final 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; } /** * Encodes a raw byte array into a BASE64 <code>char[]</code>. * * @param lineSeparator optional CRLF after 76 chars, unless EOF. */ public final 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; } public final static byte[] encodeToByte(String s) { try { return encodeToByte(s.getBytes(CharsetUtil.UTF_8), false); } catch (UnsupportedEncodingException ignore) { return new byte[]{}; } } public final static byte[] encodeToByte(String s, boolean lineSep) { try { return encodeToByte(s.getBytes(CharsetUtil.UTF_8), lineSep); } catch (UnsupportedEncodingException ignore) { return new byte[]{}; } } public final static byte[] encodeToByte(byte[] arr) { return encodeToByte(arr, false); } /** * Encodes a raw byte array into a BASE64 <code>char[]</code>. * * @param lineSep optional CRLF after 76 chars, unless EOF. */ public final 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; } public final static String decodeToString(byte[] arr) { try { return new String(decode(arr), CharsetUtil.UTF_8); } catch (UnsupportedEncodingException ignore) { return null; } } /** * Decodes BASE64 encoded byte array. */ public final 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; } public final static String encodeToString(String s) { try { return new String(encodeToChar(s.getBytes(CharsetUtil.UTF_8), false)); } catch (UnsupportedEncodingException ignore) { return null; } } public final static String encodeToString(String s, boolean lineSep) { try { return new String(encodeToChar(s.getBytes(CharsetUtil.UTF_8), lineSep)); } catch (UnsupportedEncodingException ignore) { return null; } } public final static String encodeToString(byte[] arr) { return new String(encodeToChar(arr, false)); } /** * Encodes a raw byte array into a BASE64 <code>String</code>. */ public final static String encodeToString(byte[] arr, boolean lineSep) { return new String(encodeToChar(arr, lineSep)); } public final static String decodeToString(String s) { try { return new String(decode(s), CharsetUtil.UTF_8); } catch (UnsupportedEncodingException ignore) { return null; } } /** * Decodes a BASE64 encoded string. */ public final 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; } /** * Decodes a BASE64 encoded char array. */ public final 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; } }