package com.ximple.eofms.util;
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import java.util.Arrays;
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public class Base64 {
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private static final char[] CA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
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private static final int[] IA = new int[256];
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static {
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Arrays.fill(IA, -1);
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for (int i = 0, iS = CA.length; i < iS; i++)
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IA[CA[i]] = i;
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IA['='] = 0;
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}
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// ****************************************************************************************
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// * char[] version
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// ****************************************************************************************
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/**
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* Encodes a raw byte array into a BASE64 <code>char[]</code> representation i accordance with RFC 2045.
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*
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* @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned.
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* @param lineSep Optional "\r\n" after 76 characters, unless end of file.<br>
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* No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a
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* little faster.
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* @return A BASE64 encoded array. Never <code>null</code>.
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*/
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public static char[] encodeToChar(byte[] sArr, boolean lineSep) {
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// Check special case
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int sLen = sArr != null ? sArr.length : 0;
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if (sLen == 0)
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return new char[0];
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int eLen = (sLen / 3) * 3; // Length of even 24-bits.
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int cCnt = ((sLen - 1) / 3 + 1) << 2; // Returned character count
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int dLen = cCnt + (lineSep ? (cCnt - 1) / 76 << 1 : 0); // Length of returned array
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char[] dArr = new char[dLen];
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// Encode even 24-bits
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for (int s = 0, d = 0, cc = 0; s < eLen;) {
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// Copy next three bytes into lower 24 bits of int, paying attension to sign.
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int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff);
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// Encode the int into four chars
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dArr[d++] = CA[(i >>> 18) & 0x3f];
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dArr[d++] = CA[(i >>> 12) & 0x3f];
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dArr[d++] = CA[(i >>> 6) & 0x3f];
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dArr[d++] = CA[i & 0x3f];
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// Add optional line separator
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if (lineSep && ++cc == 19 && d < dLen - 2) {
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dArr[d++] = '\r';
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dArr[d++] = '\n';
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cc = 0;
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}
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}
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// Pad and encode last bits if source isn't even 24 bits.
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int left = sLen - eLen; // 0 - 2.
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if (left > 0) {
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// Prepare the int
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int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0);
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// Set last four chars
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dArr[dLen - 4] = CA[i >> 12];
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dArr[dLen - 3] = CA[(i >>> 6) & 0x3f];
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dArr[dLen - 2] = left == 2 ? CA[i & 0x3f] : '=';
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dArr[dLen - 1] = '=';
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}
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return dArr;
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}
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/**
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* Decodes a BASE64 encoded char array. All illegal characters will be ignored and can handle both arrays with
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* and without line separators.
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*
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* @param sArr The source array. <code>null</code> or length 0 will return an empty array.
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* @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters
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* (including '=') isn't divideable by 4. (I.e. definitely corrupted).
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*/
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public static byte[] decode(char[] sArr) {
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// Check special case
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int sLen = sArr != null ? sArr.length : 0;
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if (sLen == 0)
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return new byte[0];
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// Count illegal characters (including '\r', '\n') to know what size the returned array will be,
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// so we don't have to reallocate & copy it later.
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int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
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for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
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if (IA[sArr[i]] < 0)
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sepCnt++;
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// Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
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if ((sLen - sepCnt) % 4 != 0)
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return null;
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int pad = 0;
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for (int i = sLen; i > 1 && IA[sArr[--i]] <= 0;)
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if (sArr[i] == '=')
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pad++;
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int len = ((sLen - sepCnt) * 6 >> 3) - pad;
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byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
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for (int s = 0, d = 0; d < len;) {
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// Assemble three bytes into an int from four "valid" characters.
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int i = 0;
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for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
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int c = IA[sArr[s++]];
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if (c >= 0)
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i |= c << (18 - j * 6);
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else
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j--;
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}
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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if (d < len) {
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dArr[d++] = (byte) (i >> 8);
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if (d < len)
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dArr[d++] = (byte) i;
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}
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}
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return dArr;
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}
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/**
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* Decodes a BASE64 encoded char array that is known to be resonably well formatted. The method is about twice as
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* fast as {@link #decode(char[])}. The preconditions are:<br>
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* + The array must have a line length of 76 chars OR no line separators at all (one line).<br>
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* + Line separator must be "\r\n", as specified in RFC 2045
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* + The array must not contain illegal characters within the encoded string<br>
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* + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br>
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*
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* @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception.
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* @return The decoded array of bytes. May be of length 0.
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*/
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public byte[] decodeFast(char[] sArr) {
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// Check special case
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int sLen = sArr.length;
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if (sLen == 0)
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return new byte[0];
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int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.
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// Trim illegal chars from start
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while (sIx < eIx && IA[sArr[sIx]] < 0)
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sIx++;
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// Trim illegal chars from end
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while (eIx > 0 && IA[sArr[eIx]] < 0)
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eIx--;
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// get the padding count (=) (0, 1 or 2)
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int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end.
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int cCnt = eIx - sIx + 1; // Content count including possible separators
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int sepCnt = sLen > 76 ? (sArr[76] == '\r' ? cCnt / 78 : 0) << 1 : 0;
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int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes
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byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
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// Decode all but the last 0 - 2 bytes.
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int d = 0;
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for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
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// Assemble three bytes into an int from four "valid" characters.
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int i = IA[sArr[sIx++]] << 18 | IA[sArr[sIx++]] << 12 | IA[sArr[sIx++]] << 6 | IA[sArr[sIx++]];
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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dArr[d++] = (byte) (i >> 8);
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dArr[d++] = (byte) i;
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// If line separator, jump over it.
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if (sepCnt > 0 && ++cc == 19) {
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sIx += 2;
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cc = 0;
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}
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}
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if (d < len) {
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// Decode last 1-3 bytes (incl '=') into 1-3 bytes
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int i = 0;
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for (int j = 0; sIx <= eIx - pad; j++)
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i |= IA[sArr[sIx++]] << (18 - j * 6);
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for (int r = 16; d < len; r -= 8)
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dArr[d++] = (byte) (i >> r);
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}
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return dArr;
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}
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// ****************************************************************************************
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// * byte[] version
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// ****************************************************************************************
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/**
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* Encodes a raw byte array into a BASE64 <code>byte[]</code> representation i accordance with RFC 2045.
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*
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* @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned.
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* @param lineSep Optional "\r\n" after 76 characters, unless end of file.<br>
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* No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a
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* little faster.
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* @return A BASE64 encoded array. Never <code>null</code>.
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*/
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public static byte[] encodeToByte(byte[] sArr, boolean lineSep) {
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// Check special case
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int sLen = sArr != null ? sArr.length : 0;
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if (sLen == 0)
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return new byte[0];
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int eLen = (sLen / 3) * 3; // Length of even 24-bits.
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int cCnt = ((sLen - 1) / 3 + 1) << 2; // Returned character count
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int dLen = cCnt + (lineSep ? (cCnt - 1) / 76 << 1 : 0); // Length of returned array
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byte[] dArr = new byte[dLen];
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// Encode even 24-bits
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for (int s = 0, d = 0, cc = 0; s < eLen;) {
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// Copy next three bytes into lower 24 bits of int, paying attension to sign.
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int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff);
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// Encode the int into four chars
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dArr[d++] = (byte) CA[(i >>> 18) & 0x3f];
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dArr[d++] = (byte) CA[(i >>> 12) & 0x3f];
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dArr[d++] = (byte) CA[(i >>> 6) & 0x3f];
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dArr[d++] = (byte) CA[i & 0x3f];
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// Add optional line separator
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if (lineSep && ++cc == 19 && d < dLen - 2) {
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dArr[d++] = '\r';
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dArr[d++] = '\n';
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cc = 0;
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}
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}
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// Pad and encode last bits if source isn't an even 24 bits.
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int left = sLen - eLen; // 0 - 2.
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if (left > 0) {
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// Prepare the int
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int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0);
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// Set last four chars
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dArr[dLen - 4] = (byte) CA[i >> 12];
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dArr[dLen - 3] = (byte) CA[(i >>> 6) & 0x3f];
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dArr[dLen - 2] = left == 2 ? (byte) CA[i & 0x3f] : (byte) '=';
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dArr[dLen - 1] = '=';
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}
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return dArr;
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}
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/**
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* Decodes a BASE64 encoded byte array. All illegal characters will be ignored and can handle both arrays with
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* and without line separators.
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*
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* @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception.
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* @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters
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* (including '=') isn't divideable by 4. (I.e. definitely corrupted).
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*/
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public static byte[] decode(byte[] sArr) {
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// Check special case
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int sLen = sArr.length;
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// Count illegal characters (including '\r', '\n') to know what size the returned array will be,
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// so we don't have to reallocate & copy it later.
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int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
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for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
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if (IA[sArr[i] & 0xff] < 0)
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sepCnt++;
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// Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
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if ((sLen - sepCnt) % 4 != 0)
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return null;
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int pad = 0;
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for (int i = sLen; i > 1 && IA[sArr[--i] & 0xff] <= 0;)
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if (sArr[i] == '=')
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pad++;
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int len = ((sLen - sepCnt) * 6 >> 3) - pad;
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byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
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for (int s = 0, d = 0; d < len;) {
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// Assemble three bytes into an int from four "valid" characters.
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int i = 0;
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for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
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int c = IA[sArr[s++] & 0xff];
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if (c >= 0)
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i |= c << (18 - j * 6);
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else
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j--;
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}
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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if (d < len) {
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dArr[d++] = (byte) (i >> 8);
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if (d < len)
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dArr[d++] = (byte) i;
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}
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}
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return dArr;
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}
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/**
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* Decodes a BASE64 encoded byte array that is known to be resonably well formatted. The method is about twice as
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* fast as {@link #decode(byte[])}. The preconditions are:<br>
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* + The array must have a line length of 76 chars OR no line separators at all (one line).<br>
|
* + Line separator must be "\r\n", as specified in RFC 2045
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* + The array must not contain illegal characters within the encoded string<br>
|
* + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br>
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*
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* @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception.
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* @return The decoded array of bytes. May be of length 0.
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*/
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public static byte[] decodeFast(byte[] sArr) {
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// Check special case
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int sLen = sArr.length;
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if (sLen == 0)
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return new byte[0];
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int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.
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// Trim illegal chars from start
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while (sIx < eIx && IA[sArr[sIx] & 0xff] < 0)
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sIx++;
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// Trim illegal chars from end
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while (eIx > 0 && IA[sArr[eIx] & 0xff] < 0)
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eIx--;
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// get the padding count (=) (0, 1 or 2)
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int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end.
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int cCnt = eIx - sIx + 1; // Content count including possible separators
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int sepCnt = sLen > 76 ? (sArr[76] == '\r' ? cCnt / 78 : 0) << 1 : 0;
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int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes
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byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
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// Decode all but the last 0 - 2 bytes.
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int d = 0;
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for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
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// Assemble three bytes into an int from four "valid" characters.
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int i = IA[sArr[sIx++]] << 18 | IA[sArr[sIx++]] << 12 | IA[sArr[sIx++]] << 6 | IA[sArr[sIx++]];
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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dArr[d++] = (byte) (i >> 8);
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dArr[d++] = (byte) i;
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// If line separator, jump over it.
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if (sepCnt > 0 && ++cc == 19) {
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sIx += 2;
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cc = 0;
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}
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}
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if (d < len) {
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// Decode last 1-3 bytes (incl '=') into 1-3 bytes
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int i = 0;
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for (int j = 0; sIx <= eIx - pad; j++)
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i |= IA[sArr[sIx++]] << (18 - j * 6);
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for (int r = 16; d < len; r -= 8)
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dArr[d++] = (byte) (i >> r);
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}
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return dArr;
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}
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// ****************************************************************************************
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// * String version
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// ****************************************************************************************
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/**
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* Encodes a raw byte array into a BASE64 <code>String</code> representation i accordance with RFC 2045.
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*
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* @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned.
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* @param lineSep Optional "\r\n" after 76 characters, unless end of file.<br>
|
* No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a
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* little faster.
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* @return A BASE64 encoded array. Never <code>null</code>.
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*/
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public static String encodeToString(byte[] sArr, boolean lineSep) {
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// Reuse char[] since we can't create a String incrementally anyway and StringBuffer/Builder would be slower.
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return new String(encodeToChar(sArr, lineSep));
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}
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/**
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* Decodes a BASE64 encoded <code>String</code>. All illegal characters will be ignored and can handle both strings with
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* and without line separators.<br>
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* <b>Note!</b> It can be up to about 2x the speed to call <code>decode(str.toCharArray())</code> instead. That
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* will create a temporary array though. This version will use <code>str.charAt(i)</code> to iterate the string.
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*
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* @param str The source string. <code>null</code> or length 0 will return an empty array.
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* @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters
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* (including '=') isn't divideable by 4. (I.e. definitely corrupted).
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*/
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public static byte[] decode(String str) {
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// Check special case
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int sLen = str != null ? str.length() : 0;
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if (sLen == 0)
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return new byte[0];
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// Count illegal characters (including '\r', '\n') to know what size the returned array will be,
|
// so we don't have to reallocate & copy it later.
|
int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...)
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for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out.
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if (IA[str.charAt(i)] < 0)
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sepCnt++;
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// Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045.
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if ((sLen - sepCnt) % 4 != 0)
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return null;
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// Count '=' at end
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int pad = 0;
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for (int i = sLen; i > 1 && IA[str.charAt(--i)] <= 0;)
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if (str.charAt(i) == '=')
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pad++;
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int len = ((sLen - sepCnt) * 6 >> 3) - pad;
|
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byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
|
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for (int s = 0, d = 0; d < len;) {
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// Assemble three bytes into an int from four "valid" characters.
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int i = 0;
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for (int j = 0; j < 4; j++) { // j only increased if a valid char was found.
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int c = IA[str.charAt(s++)];
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if (c >= 0)
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i |= c << (18 - j * 6);
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else
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j--;
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}
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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if (d < len) {
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dArr[d++] = (byte) (i >> 8);
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if (d < len)
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dArr[d++] = (byte) i;
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}
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}
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return dArr;
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}
|
|
/**
|
* Decodes a BASE64 encoded string that is known to be resonably well formatted. The method is about twice as
|
* fast as {@link #decode(String)}. The preconditions are:<br>
|
* + The array must have a line length of 76 chars OR no line separators at all (one line).<br>
|
* + Line separator must be "\r\n", as specified in RFC 2045
|
* + The array must not contain illegal characters within the encoded string<br>
|
* + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br>
|
*
|
* @param s The source string. Length 0 will return an empty array. <code>null</code> will throw an exception.
|
* @return The decoded array of bytes. May be of length 0.
|
*/
|
public static byte[] decodeFast(String s) {
|
// Check special case
|
int sLen = s.length();
|
if (sLen == 0)
|
return new byte[0];
|
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int sIx = 0, eIx = sLen - 1; // Start and end index after trimming.
|
|
// Trim illegal chars from start
|
while (sIx < eIx && IA[s.charAt(sIx) & 0xff] < 0)
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sIx++;
|
|
// Trim illegal chars from end
|
while (eIx > 0 && IA[s.charAt(eIx) & 0xff] < 0)
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eIx--;
|
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// get the padding count (=) (0, 1 or 2)
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int pad = s.charAt(eIx) == '=' ? (s.charAt(eIx - 1) == '=' ? 2 : 1) : 0; // Count '=' at end.
|
int cCnt = eIx - sIx + 1; // Content count including possible separators
|
int sepCnt = sLen > 76 ? (s.charAt(76) == '\r' ? cCnt / 78 : 0) << 1 : 0;
|
|
int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes
|
byte[] dArr = new byte[len]; // Preallocate byte[] of exact length
|
|
// Decode all but the last 0 - 2 bytes.
|
int d = 0;
|
for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) {
|
// Assemble three bytes into an int from four "valid" characters.
|
int i = IA[s.charAt(sIx++)] << 18 | IA[s.charAt(sIx++)] << 12 | IA[s.charAt(sIx++)] << 6 | IA[s.charAt(sIx++)];
|
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// Add the bytes
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dArr[d++] = (byte) (i >> 16);
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dArr[d++] = (byte) (i >> 8);
|
dArr[d++] = (byte) i;
|
|
// If line separator, jump over it.
|
if (sepCnt > 0 && ++cc == 19) {
|
sIx += 2;
|
cc = 0;
|
}
|
}
|
|
if (d < len) {
|
// Decode last 1-3 bytes (incl '=') into 1-3 bytes
|
int i = 0;
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for (int j = 0; sIx <= eIx - pad; j++)
|
i |= IA[s.charAt(sIx++)] << (18 - j * 6);
|
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for (int r = 16; d < len; r -= 8)
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dArr[d++] = (byte) (i >> r);
|
}
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return dArr;
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}
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}
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