Bitmap和Base64之间的转换以及Base64 encode

/**   *bitmap转成String   */public static String bitmaptoString(Bitmap bitmap) {    if (bitmap == null) {        return "";    }    String string = null;    ByteArrayOutputStream bStream = new ByteArrayOutputStream();    bitmap.compress(Bitmap.CompressFormat.JPEG, 50, bStream);    byte[] bytes = bStream.toByteArray();    Base64Encoder base = new Base64Encoder();    string = base.encode(bytes); //    return string;}/** * base64转为bitmap */public static Bitmap base64ToBitmap(String base64Data) {    byte[] bytes = Base64.decode(base64Data, Base64.DEFAULT);    return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);}
/** * base64 encode */

public class Base64Encoder {    private static final char last2byte = (char) Integer            .parseInt("00000011", 2);    private static final char last4byte = (char) Integer            .parseInt("00001111", 2);    private static final char last6byte = (char) Integer            .parseInt("00111111", 2);    private static final char lead6byte = (char) Integer            .parseInt("11111100", 2);    private static final char lead4byte = (char) Integer            .parseInt("11110000", 2);    private static final char lead2byte = (char) Integer            .parseInt("11000000", 2);    private static final char[] encodeTable = 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', '+', '/' };    /**     * Base64 encoding.     *     * @param from     *            The src data.     * @return     */    public static String encode(byte[] from) {        StringBuffer to = new StringBuffer((int) (from.length * 1.34) + 3);        int num = 0;        char currentByte = 0;        for (int i = 0; i < from.length; i++) {            num = num % 8;            while (num < 8) {                switch (num) {                    case 0:                        currentByte = (char) (from[i] & lead6byte);                        currentByte = (char) (currentByte >>> 2);                        break;                    case 2:                        currentByte = (char) (from[i] & last6byte);                        break;                    case 4:                        currentByte = (char) (from[i] & last4byte);                        currentByte = (char) (currentByte << 2);                        if ((i + 1) < from.length) {                            currentByte |= (from[i + 1] & lead2byte) >>> 6;                        }                        break;                    case 6:                        currentByte = (char) (from[i] & last2byte);                        currentByte = (char) (currentByte << 4);                        if ((i + 1) < from.length) {                            currentByte |= (from[i + 1] & lead4byte) >>> 4;                        }                        break;                }                to.append(encodeTable[currentByte]);                num += 6;            }        }        if (to.length() % 4 != 0) {            for (int i = 4 - to.length() % 4; i > 0; i--) {                to.append("=");            }        }        return to.toString();    }}