Android Base64加密解密算法

Android SDK中没有给我们提供Base64算法，只能自己去实现，自己Google了一些资料，实现了一个Base64算法的工具类，需要的可以直接拿着用

Java源代码：

/** * BASE 64 加密解密 工具类 *  * @author FX_SKY 2012.10.25 * */public class BASE64Util {private static final char[] base64EncodeChars = 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', '+', '/' };private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,-1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,-1, -1 };/** * 将字节数组编码为字符串 *  * @param data */public static String encode(byte[] data) {StringBuffer sb = new StringBuffer();int len = data.length;int i = 0;int b1, b2, b3;while (i < len) {b1 = data[i++] & 0xff;if (i == len) {sb.append(base64EncodeChars[b1 >>> 2]);sb.append(base64EncodeChars[(b1 & 0x3) << 4]);sb.append("==");break;}b2 = data[i++] & 0xff;if (i == len) {sb.append(base64EncodeChars[b1 >>> 2]);sb.append(base64EncodeChars[((b1 & 0x03) << 4)| ((b2 & 0xf0) >>> 4)]);sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);sb.append("=");break;}b3 = data[i++] & 0xff;sb.append(base64EncodeChars[b1 >>> 2]);sb.append(base64EncodeChars[((b1 & 0x03) << 4)| ((b2 & 0xf0) >>> 4)]);sb.append(base64EncodeChars[((b2 & 0x0f) << 2)| ((b3 & 0xc0) >>> 6)]);sb.append(base64EncodeChars[b3 & 0x3f]);}return sb.toString();}/** * 将base64字符串解码为字节数组 *  * @param str */public static byte[] decode(String str) {byte[] data = str.getBytes();int len = data.length;ByteArrayOutputStream buf = new ByteArrayOutputStream(len);int i = 0;int b1, b2, b3, b4;while (i < len) {/* b1 */do {b1 = base64DecodeChars[data[i++]];} while (i < len && b1 == -1);if (b1 == -1) {break;}/* b2 */do {b2 = base64DecodeChars[data[i++]];} while (i < len && b2 == -1);if (b2 == -1) {break;}buf.write((int) ((b1 << 2) | ((b2 & 0x30) >>> 4)));/* b3 */do {b3 = data[i++];if (b3 == 61) {return buf.toByteArray();}b3 = base64DecodeChars[b3];} while (i < len && b3 == -1);if (b3 == -1) {break;}buf.write((int) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));/* b4 */do {b4 = data[i++];if (b4 == 61) {return buf.toByteArray();}b4 = base64DecodeChars[b4];} while (i < len && b4 == -1);if (b4 == -1) {break;}buf.write((int) (((b3 & 0x03) << 6) | b4));}return buf.toByteArray();}}