获取安装包签名

PackageManager manager = getPackageManager();
        /** 通过包管理器获得指定包名包含签名的包信息 **/
        PackageInfo packageInfo = null;
        try {
            packageInfo = manager.getPackageInfo("包名", PackageManager.GET_SIGNATURES);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        /******* 通过返回的包信息获得签名数组 *******/
        Signature[] signatures = packageInfo.signatures;
        String ss = MD5.hexdigest(signatures[0].toByteArray());
        if (ss != null) {
            Log.e("test", ss + "---------------");
            Toast.makeText(this, "签名" + ss, Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(this, "没获得签名", Toast.LENGTH_LONG).show();
        }

public class MD5 {

    private static final char[] hexDigits = { 48, 49, 50, 51, 52, 53, 54, 55,
            56, 57, 97, 98, 99, 100, 101, 102 };

    public static String hexdigest(String paramString) {
        try {
            String str = hexdigest(paramString.getBytes());
            return str;
        } catch (Exception localException) {
        }
        return null;
    }

    public static String hexdigest(byte[] paramArrayOfByte) {
        try {
            MessageDigest localMessageDigest = MessageDigest.getInstance("MD5");
            localMessageDigest.update(paramArrayOfByte);
            byte[] arrayOfByte = localMessageDigest.digest();
            char[] arrayOfChar = new char[32];
            int i = 0;
            int j = 0;
            while (true) {
                if (i >= 16)
                    return new String(arrayOfChar);
                int k = arrayOfByte[i];
                int m = j + 1;
                arrayOfChar[j] = hexDigits[(0xF & k >>> 4)];
                j = m + 1;
                arrayOfChar[m] = hexDigits[(k & 0xF)];
                i++;
            }
        } catch (Exception localException) {
        }
        return null;
    }




}