Android 对字符串进行MD5 和base64 加密

对字符串进行MD5加密

/**
 * MD5加密
 * @param str 内容
 * @param charset 编码方式
 * @throws Exception
 */
@SuppressWarnings("unused")
public static String MD5(String str, String charset) throws Exception {
    MessageDigest md = MessageDigest.getInstance("MD5");
    md.update(str.getBytes(charset));
    byte[] result = md.digest();
    StringBuffer sb = new StringBuffer(32);
    for (int i = 0; i < result.length; i++) {
        int val = result[i] & 0xff;
        if (val <= 0xf) {
            sb.append("0");
        }
        sb.append(Integer.toHexString(val));
    }
    return sb.toString().toLowerCase();
}

对字符串进行base64加密

/**
 * base64编码
 * @param str 内容
 * @param charset 编码方式
 * @throws UnsupportedEncodingException
 */
public static String base64(String str, String charset) throws UnsupportedEncodingException {
    String encoded = base64Encode(str.getBytes(charset));
    return encoded;
}

private static 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', '+', '/' };

public static String base64Encode(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();
}