import java.util.UUID;

import java.util.Map;

import java.util.HashMap;

import java.util.Formatter;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.io.UnsupportedEncodingException;  

class Sign {

    public static void main(String[] args) {

        String jsapi_ticket = "jsapi_ticket";

        // 注意 URL 一定要动态获取，不能 hardcode

        String url = "http://example.com";

        Map<String, String> ret = sign(jsapi_ticket, url);

        for (Map.Entry entry : ret.entrySet()) {

            System.out.println(entry.getKey() + ", " + entry.getValue());

        }

    };

    public static Map<String, String> sign(String jsapi_ticket, String url) {

        Map<String, String> ret = new HashMap<String, String>();

        String nonce_str = create_nonce_str();

        String timestamp = create_timestamp();

        String string1;

        String signature = "";

        //注意这里参数名必须全部小写，且必须有序

        string1 = "jsapi_ticket=" + jsapi_ticket +

                  "&noncestr=" + nonce_str +

                  "&timestamp=" + timestamp +

                  "&url=" + url;

        System.out.println(string1);

        try

        {

            MessageDigest crypt = MessageDigest.getInstance("SHA-1");

            crypt.reset();

            crypt.update(string1.getBytes("UTF-8"));

            signature = byteToHex(crypt.digest());

        }

        catch (NoSuchAlgorithmException e)

        {

            e.printStackTrace();

        }

        catch (UnsupportedEncodingException e)

        {

            e.printStackTrace();

        }

        ret.put("url", url);

        ret.put("jsapi_ticket", jsapi_ticket);

        ret.put("nonceStr", nonce_str);

        ret.put("timestamp", timestamp);

        ret.put("signature", signature);

        return ret;

    }

    private static String byteToHex(final byte[] hash) {

        Formatter formatter = new Formatter();

        for (byte b : hash)

        {

            formatter.format("%02x", b);

        }

        String result = formatter.toString();

        formatter.close();

        return result;

    }

    private static String create_nonce_str() {

        return UUID.randomUUID().toString();

    }

    private static String create_timestamp() {

        return Long.toString(System.currentTimeMillis() / 1000);

    }

}