微信公众号支付

如果出现签名错误请校验签名
地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=20_1

		String mchid = mchid;// 商户id
		String appid = appid;// 公众号appid
		String key = key; // 商户key

		String original_sn = sn;//订单号
		String body = "网店订单[" + original_sn + "]";//商品名称

		HttpServletRequest request = ThreadContextHolder.getHttpRequest();
		Map params = new TreeMap();
		params.put("appid", appid);
		params.put("mch_id", mchid);
		params.put("nonce_str", StringUtil.getRandStr(10));//随机数
		params.put("body", body);
		params.put("out_trade_no", original_sn);
		// 付款金额转为分
		Double money = ;//
		params.put("total_fee", toFen(money));//将付款金额转为分
		params.put("spbill_create_ip", request.getRemoteAddr());//获取ip
		params.put("notify_url",  );//回调的url
		params.put("trade_type", "JSAPI");
		
		//获取openid
		String openid = ;
		
		params.put("openid", openid);
		System.out.println("openid:"+openid);
		String sign = WeixinUtil.createSign(params, key);//签名
		params.put("sign", sign);
		String result = "";
		try {
			String xml = WeixinUtil.mapToXml(params);//将结果拼装成xml
			Document resultDoc = WeixinUtil.post("https://api.mch.weixin.qq.com/pay/unifiedorder", xml);
			Element rootEl = resultDoc.getRootElement();
			// 返回结果
			String return_code = rootEl.element("return_code").getText(); // 返回码
			if ("SUCCESS".equals(return_code)) {
				String result_code = rootEl.element("result_code").getText(); // 业务码
				if ("SUCCESS".equals(result_code)) {
					String prepay_id = rootEl.element("prepay_id").getText(); // 预支付订单id
					
					result = this.getPayScript(prepay_id, appid, key,original_sn,bill.getTradeType());

				} else {
					
					String err_code = rootEl.element("err_code").getText();
					String err_code_des = rootEl.element("err_code_des").getText();
					result = "";
				}
			} else {
				result = "";
				if ("FAIL".equals(return_code)) {
					String return_msg = resultDoc.getRootElement()
							.element("return_msg").getText(); // 错误信息
				}
			}
		} catch (Exception e) {
			this.logger.error("微信生成支付二维码错误", e);
			return "二维码生成错误";
		}

		return result;

 

public static String getRandStr(int n) {
		Random random = new Random();
		String sRand = "";
		for (int i = 0; i < n; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
		}
		return sRand;
	}

protected String toFen(Double money) {
		String value = BigDecimal.valueOf(money).multiply(new BigDecimal(100)).toString();
		
		NumberFormat numberFormat = new DecimalFormat("##");
		
		return numberFormat.format(new BigDecimal(value));
	}

	/**
	 * 生成签名
	 * 
	 * @param params
	 *            参数map
	 * @param key
	 *            支付key(API密钥)
	 * @return
	 */
	public static String createSign(Map params, String key) {
		 
		String url = createLinkString(params);
		url = url + "&key=" + key;
		String sign = DigestUtils.md5Hex(url).toUpperCase();
		return sign;
	}

	public static String createLinkString(Map params) {

		List keys = new ArrayList(params.keySet());
		Collections.sort(keys);

		String prestr = "";

		for (int i = 0; i < keys.size(); i++) {
			String key = keys.get(i);
			String value = params.get(key);
			
			if("sign".equals(key)){
				continue;
			}
			
			if ("".equals(prestr)) {// 拼接时，不包括最后一个&字符
				prestr = prestr + key + "=" + value;
			} else {
				prestr = prestr +"&" +key + "=" + value ;
			}
		}
		return prestr;
	}

 

	/**
     * 将Map转换为XML格式的字符串
     *
     * @param data Map类型数据
     * @return XML格式的字符串
     * @throws Exception
     */
    public static String mapToXml(Map data) throws Exception {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder= documentBuilderFactory.newDocumentBuilder();
        org.w3c.dom.Document document = documentBuilder.newDocument();
        org.w3c.dom.Element root = document.createElement("xml");
        document.appendChild(root);
        for (String key: data.keySet()) {
            String value = data.get(key);
            if (value == null) {
                value = "";
            }
            value = value.trim();
            org.w3c.dom.Element filed = document.createElement(key);
            filed.appendChild(document.createTextNode(value));
            root.appendChild(filed);
        }
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        DOMSource source = new DOMSource(document);
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        StringWriter writer = new StringWriter();
        StreamResult result = new StreamResult(writer);
        transformer.transform(source, result);
        String output = writer.getBuffer().toString(); //.replaceAll("\n|\r", "");
        try {
            writer.close();
        }
        catch (Exception ex) {
        }
        return output;
    }

	public static Document post(String wsPart, String doc_str) {
		try {
			
			HttpClient httpclient = new DefaultHttpClient();
			HttpPost httppost = new HttpPost(wsPart);
			HttpEntity requestEntity = new StringEntity(doc_str,"UTF-8");
			
			httppost.setEntity(requestEntity);
			httppost.setHeader(HTTP.CONTENT_ENCODING, HTTP.UTF_8);
			HttpResponse httpresponse = httpclient.execute(httppost);
			HttpEntity rentity = httpresponse.getEntity();
			InputStream in = rentity.getContent();
			if (in != null) {
				SAXReader reader = new SAXReader();
				Document doc = reader.read(in);
				return doc;
			} else {
				throw new RuntimeException("post uri[" + wsPart
						+ "]发生错误:[stream 返回Null]");
			}
		} catch (Throwable e) {

			throw new RuntimeException("post uri [" + wsPart + "]发生错误", e);

		}
	}