Here you can find the source of toBase64(byte[] data)
| Parameter | Description |
|---|---|
| data | a byte array, which may be null or empty |
public static String toBase64(byte[] data)
//package com.java2s; //License from project: Apache License public class Main { private static final char[] base64Chars = new char[] { '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', '+', '/' }; /**// w w w . ja v a 2s .c o m * Converts a byte array into a base 64 encoded string. Null is encoded as null, and an empty array is encoded as an * empty string. Otherwise, the byte data is read 3 bytes at a time, with bytes off the end of the array padded with * zeros. Each 24-bit chunk is encoded as 4 characters from the sequence [A-Za-z0-9$_]. If one of the size-bit * source positions consists entirely of padding zeros, an '=' character is used instead. * * @param data * a byte array, which may be null or empty * @return a String */ public static String toBase64(byte[] data) { if (data == null) { return null; } int len = data.length; if (len == 0) { return ""; } int olen = 4 * ((len + 2) / 3); char[] chars = new char[olen]; int iidx = 0; int oidx = 0; int charsLeft = len; while (charsLeft > 0) { int b0 = data[iidx++] & 0xff; int b1 = (charsLeft > 1) ? data[iidx++] & 0xff : 0; int b2 = (charsLeft > 2) ? data[iidx++] & 0xff : 0; int b24 = (b0 << 16) | (b1 << 8) | b2; int c0 = (b24 >> 18) & 0x3f; int c1 = (b24 >> 12) & 0x3f; int c2 = (b24 >> 6) & 0x3f; int c3 = b24 & 0x3f; chars[oidx++] = base64Chars[c0]; chars[oidx++] = base64Chars[c1]; chars[oidx++] = (charsLeft > 1) ? base64Chars[c2] : '='; chars[oidx++] = (charsLeft > 2) ? base64Chars[c3] : '='; charsLeft -= 3; } return new String(chars); } }