微信转发

不敢标原创，感谢 柳峰老师和另一位dalao（http://my.csdn.net/wgyscsf）

$(function() {
		//微信转发
		$.ajax({
			type : "post",
			url : "index_WxZhuanFa",
			dataType : "json",
			data : {
				"url" : location.href.split('#')[0],
			},
			success : function(data) {
				//alert(data.signature)
				fx(data.timestamp, data.nonceStr, data.signature);
			},
			error : function() {
				alert("WTF?");
			}
		});
	}); 	

	function fx(timestamp, nonceStr, signature) {
		//alert(timestamp + '==' + nonceStr + '==' + signature)
		wx.config({
			debug : false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
			appId : '', // 必填，公众号的唯一标识
			timestamp : timestamp, // 必填，生成签名的时间戳
			nonceStr : nonceStr, // 必填，生成签名的随机串
			signature : signature,// 必填，签名，见附录1
			jsApiList : [ 'onMenuShareAppMessage', 'onMenuShareTimeline' ]
		// 必填，需要使用的JS接口列表，所有JS接口列表见附录2
		});

		wx.ready(function() {
			wx.onMenuShareTimeline({
				title : '',// 分享标题
				link : '',// 分享链接
				imgUrl : '',//分享图标
				success : function() {
					// 用户确认分享后执行的回调函数
					alert('分享到朋友圈成功');
				},
				cancel : function() {
					// 用户取消分享后执行的回调函数
					alert('你没有分享到朋友圈');
				}
			});
			wx.onMenuShareAppMessage({
				title : '', // 分享标题
				desc : '', // 分享描述
				link : '', // 分享链接
				imgUrl : '', // 分享图标
				type : '', // 分享类型,music、video或link，不填默认为link
				dataUrl : '', // 如果type是music或video，则要提供数据链接，默认为空
				success : function() {
					// 用户确认分享后执行的回调函数
					alert("分享成功")
				},
				cancel : function() {
					// 用户取消分享后执行的回调函数
					alert("分享取消")
				}
			});
		});
	}

/**
	 * 微信转发
	 * 
	 * @throws IOException
	 */
	public void WxZhuanFa() throws IOException {
		HttpServletRequest request = ServletActionContext.getRequest();
		HttpServletResponse response = ServletActionContext.getResponse();
		PrintWriter out = response.getWriter();

		String AccessToken = null;
		try {
			AccessToken = WxAccessToken.getSavedAccess_token();
		} catch (IOException e) {
			System.out.println("微信转发：AccessToken拿失败");
		}
		String ticket = null;
		try {
			ticket = WxJsapi_ticket.getSaveJsapi_ticket(AccessToken);
		} catch (IOException e) {
			System.out.println("微信转发：ticket拿失败");
		}
		String jsapi_ticket = ticket;

		// 注意 URL 一定要动态获取，不能 hardcode
		String url = request.getParameter("url");
		Map<String, String> ret = Sign.sign(jsapi_ticket, url);
		/*for (Map.Entry entry : ret.entrySet()) {
			System.out.println(entry.getKey() + ", " + entry.getValue());
		}*/
		JSONObject jsonObject = JSONObject.fromObject(ret);
		out.println(jsonObject);
		out.flush();
		out.close();
	}

public class WxAccessToken {
	private static final long MAX_TIME = 7200 * 1000;// 微信允许最长Access_token有效时间（ms）

	/**
	 * 获取Access_token 保存并且只保存2小时Access_token。如果超过两个小时重新获取；如果没有超过两个小时，直接获取
	 * 思路:将获取到的Access_token和当前时间存储到file里，
	 * 取出时判断当前时间和存储里面的记录的时间的时间差，如果大于MAX_TIME,重新获取，并且将获取到的存储到file替换原来的内容
	 * ，如果小于MAX_TIME，直接获取。
	 * 
	 * @throws IOException
	 */
	public static String getSavedAccess_token() throws IOException {
		Gson gson = new Gson();
		String mAccess_token = null;// 需要获取的Access_token；
		File file = new File("temp_access_token.temp");// Access_token保存的位置
		// 如果文件不存在，创建
		if (!file.exists())
			file.createNewFile();
		// 如果文件大小等于0，说明第一次使用，存入Access_token
		if (file.length() == 0) {
			mAccess_token = getAccessToken();
			FileOutputStream fos = new FileOutputStream(file, false);// 不允许追加
			Access_token at = new Access_token();
			at.setAccess_token(mAccess_token);
			at.setExpires_in(System.currentTimeMillis() + "");
			String json = gson.toJson(at);
			fos.write((json).getBytes());
			fos.close();
		} else {
			// 读取文件内容
			FileInputStream fis = new FileInputStream(file);
			byte[] b = new byte[2048];
			int len = fis.read(b);
			String mJsonAccess_token = new String(b, 0, len);// 读取到的文件内容
			Access_token access_token = gson.fromJson(mJsonAccess_token, new Access_token().getClass());
			if (access_token.getExpires_in() != null) {
				long saveTime = Long.parseLong(access_token.getExpires_in());
				long nowTime = System.currentTimeMillis();
				long remianTime = nowTime - saveTime;
				//System.out.println(TAG + "时间差：" + remianTime);
				if (remianTime < MAX_TIME) {
					Access_token at = gson.fromJson(mJsonAccess_token, new Access_token().getClass());
					mAccess_token = at.getAccess_token();
				} else {
					mAccess_token = getAccessToken();
					FileOutputStream fos = new FileOutputStream(file, false);// 不允许追加
					Access_token at = new Access_token();
					at.setAccess_token(mAccess_token);
					at.setExpires_in(System.currentTimeMillis() + "");
					String json = gson.toJson(at);
					fos.write((json).getBytes());
					fos.close();
				}

			}
		}
		//System.out.println("获取到的Access_token是：" + mAccess_token);
		return mAccess_token;
		
	}

	public static String getAccessToken() {
		String urlString = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="
				+ Constant.APPID + "&secret=" + Constant.SERCRET;
		String reslut = null;
		try {
			URL reqURL = new URL(urlString);
			HttpsURLConnection httpsConn = (HttpsURLConnection) reqURL.openConnection();
			InputStreamReader isr = new InputStreamReader(httpsConn.getInputStream());
			char[] chars = new char[1024];
			reslut = "";
			int len;
			while ((len = isr.read(chars)) != -1) {
				reslut += new String(chars, 0, len);
			}
			isr.close();
		} catch (IOException e) {

			e.printStackTrace();
		}
		Gson gson = new Gson();
		Access_token access_token = gson.fromJson(reslut, new Access_token().getClass());
		if (access_token.getAccess_token() != null) {
			return access_token.getAccess_token();
		} else {
			return null;
		}
	}
}

public class WxJsapi_ticket {
	private static final long MAX_TIME = 7200 * 1000;// 微信允许最长Jsapi_ticket有效时间（ms）

	/**
	 * 获取并保存Jsapi_ticket
	 * 
	 * @throws IOException
	 */
	public static String getSaveJsapi_ticket(String ACCESS_TOKEN) throws IOException {
		Gson gson = new Gson();
		String ticket = null;// 需要获取的
		File file = new File("temp_jsapi_ticket.temp");// Access_token保存的位置
		// 如果文件不存在，创建
		if (!file.exists())
			file.createNewFile();
		// 如果文件大小等于0，说明第一次使用，存入Access_token
		if (file.length() == 0) {
			ticket = getJsapi_ticket(ACCESS_TOKEN);
			FileOutputStream fos = new FileOutputStream(file, false);// 不允许追加

			Jsapi_ticket jt = new Jsapi_ticket();
			jt.setTicket(ticket);
			jt.setExpires_in(System.currentTimeMillis() + "");
			String json = gson.toJson(jt);
			fos.write((json).getBytes());
			fos.close();
		} else {
			// 读取文件内容
			FileInputStream fis = new FileInputStream(file);
			byte[] b = new byte[2048];
			int len = fis.read(b);
			String mJsonAccess_token = new String(b, 0, len);// 读取到的文件内容

			Jsapi_ticket jsapi_ticket = gson.fromJson(mJsonAccess_token, new Jsapi_ticket().getClass());
			if (jsapi_ticket.getExpires_in() != null) {
				long saveTime = Long.parseLong(jsapi_ticket.getExpires_in());
				long nowTime = System.currentTimeMillis();
				long remianTime = nowTime - saveTime;
				// System.out.println(TAG + "时间差：" + remianTime);
				if (remianTime < MAX_TIME) {
					Jsapi_ticket jt = gson.fromJson(mJsonAccess_token, new Jsapi_ticket().getClass());
					ticket = jt.getTicket();
				} else {
					ticket = getJsapi_ticket(ACCESS_TOKEN);
					FileOutputStream fos = new FileOutputStream(file, false);// 不允许追加

					Jsapi_ticket jt = new Jsapi_ticket();
					jt.setTicket(ticket);
					jt.setExpires_in(System.currentTimeMillis() + "");
					String json = gson.toJson(jt);
					fos.write((json).getBytes());
					fos.close();
				}

			}
		}
		//System.out.println("获取到的ticket是：" + ticket);
		return ticket;
	}

	public static String getJsapi_ticket(String ACCESS_TOKEN) throws IOException {
		// String ACCESS_TOKEN=getSavedAccess_token();
		// 拼接api要求的httpsurl链接
		String urlString = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + ACCESS_TOKEN
				+ "&type=jsapi";// ACCESS_TOKEN
		// 创建一个url
		URL reqURL = new URL(urlString);
		// 拿取链接
		HttpsURLConnection httpsConn = (HttpsURLConnection) reqURL.openConnection();
		// 取得该连接的输入流，以读取响应内容
		InputStreamReader isr = new InputStreamReader(httpsConn.getInputStream());
		// 读取服务器的响应内容并显示
		char[] chars = new char[1024];
		String reslut = "";
		int len;
		while ((len = isr.read(chars)) != -1) {
			reslut += new String(chars, 0, len);
		}
		isr.close();
		/*
		 * 转化json成javabean。引入了第三方jar:GSON
		 */
		Gson gson = new Gson();// 将获取的json转化为java中的bean
		// 注意：Access_token access_token是一个自己创建的javabean
		Jsapi_ticket jsapiTicket = gson.fromJson(reslut, new Jsapi_ticket().getClass());
		if (jsapiTicket.getTicket() != null) {
			// System.out.println("获取的Jsapi_ticket是："+ jsapiTicket.getTicket());
			// System.out.println("该Jsapi_ticket的有效时间是："+
			// jsapiTicket.getExpires_in() + "s");
			return jsapiTicket.getTicket();
		} else {
			// System.out.println(TAG + "获取Jsapi_ticket失败，请检查");
			return null;
		}
	}
}

public class Sign {
	public static Map sign(String jsapi_ticket, String url) {
		Map ret = new HashMap();
		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 + "×tamp=" + 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);
	}
}