public class AlipayAuth {
	
	// 支付宝网关
	private final static String alipayGatewayNew = "http://wappaygw.alipay.com/service/rest.htm?";
	
	private final static String inputCharset = "utf-8";
	
	private String key = "";//从支付宝获取的密钥
	
	//接口名称
	private final static String service = "alipay.wap.trade.create.direct";
	
	//请求参数格式
	private final static String format = "xml";
	
	//接口版本号
	private final static String v = "2.0";
	
	//合作者身份id
	public String partner = "2088000000000000";//填写从支付宝得到的id
	
	//请求号
	private String reqId;
	
	//签名方式
	private final static String secId = "MD5";
	
	//签名
	private String sign;
	
	//请求业务参数
	private String reqData;
	
	//商品名称
	private String subject;
	
	//商务网站唯一订单号
	private String outTradeNo;

	//交易金额
	private String totalFee;
	
	//卖家支付宝账号
	private String sellerAccountName;
	
	//支付成功跳转路径
	private String callBackUrl = "callBack";
	
	//服务器异步通知页面路径 (可空)
	private String notifyUrl = "notify";
	
	//商户系统唯一标示(可空)
	private String outUser;
	
	//操作中断返回地址(可空)
	private String merchantUrl;
	
	//交易自动关闭时间(可空)
	private String payExpire;
	
	//代理人id(可空)
	private String agentId;

	

	public String getBasePath() {
		return basePath;
	}
	public void setBasePath(String basePath) {
		this.basePath = basePath;
	}
	public String getAlipayGatewayNew() {
		return alipayGatewayNew;
	}
	public String getKey() {
		return key;
	}
	public void setKey(String key) {
		this.key = key;
	}
	public String getInputCharset() {
		return inputCharset;
	}
	public String getService() {
		return service;
	}
	public String getFormat() {
		return format;
	}
	public String getV() {
		return v;
	}
	public String getPartner() {
		return partner;
	}
	public void setPartner(String partner) {
		this.partner = partner;
	}
	public String getReqId() {
		return reqId;
	}
	public void setReqId(String reqId) {
		this.reqId = reqId;
	}
	public String getSecId() {
		return secId;
	}
	public String getSign() {
		return sign;
	}
	public void setSign(String sign) {
		this.sign = sign;
	}
	public String getSubject() {
		return subject;
	}
	public void setSubject(String subject) {
		this.subject = subject;
	}
	public String getOutTradeNo() {
		return outTradeNo;
	}
	public void setOutTradeNo(String outTradeNo) {
		this.outTradeNo = outTradeNo;
	}
	public String getTotalFee() {
		return totalFee;
	}
	public void setTotalFee(String totalFee) {
		this.totalFee = totalFee;
	}
	public String getSellerAccountName() {
		return sellerAccountName;
	}
	public void setSellerAccountName(String sellerAccountName) {
		this.sellerAccountName = sellerAccountName;
	}
	public String getCallBackUrl() {
		return callBackUrl;
	}
	public void setCallBackUrl(String callBackUrl) {
		this.callBackUrl = callBackUrl;
	}
	public String getNotifyUrl() {
		return notifyUrl;
	}
	public void setNotifyUrl(String notifyUrl) {
		this.notifyUrl = notifyUrl;
	}
	public String getOutUser() {
		return outUser;
	}
	public void setOutUser(String outUser) {
		this.outUser = outUser;
	}
	public String getMerchantUrl() {
		return merchantUrl;
	}
	public void setMerchantUrl(String merchantUrl) {
		this.merchantUrl = merchantUrl;
	}
	public String getPayExpire() {
		return payExpire;
	}
	public void setPayExpire(String payExpire) {
		this.payExpire = payExpire;
	}
	public String getAgentId() {
		return agentId;
	}
	public void setAgentId(String agentId) {
		this.agentId = agentId;
	}
	public void setReqData(String reqData) {
		this.reqData = reqData;
	}
	public String getReqData() {
		
		reqData = "<direct_trade_create_req>"
					+ "<subject>" + subject + "</subject>"//商品名称
					+ "<out_trade_no>" + outTradeNo + "</out_trade_no>"//商户网站唯一订单号
					+ "<total_fee>" + totalFee + "</total_fee>"//交易金额
					+ "<seller_account_name>" + sellerAccountName + "</seller_account_name>"//卖家支付宝账号
					+ "<call_back_url>" + callBackUrl + "</call_back_url>"//支付成功跳转页面
					+ "<notify_url>" + notifyUrl + "</notify_url>"//异步通知页面
					//+ "<merchantUrl>" + merchantUrl + "</merchantUrl>"//操作终端返回地址(可空)
				+ "</direct_trade_create_req>";
		return reqData;
	}	
}

public String pay() throws Exception {

		AlipayAuth alipayAuth = new AlipayAuth();
		alipayAuth.setReqId("请求号：可以用系统当前时间(精确到毫秒),作为一个唯一的请求号");
		alipayAuth.setSubject("商品名称");
		alipayAuth.setOutTradeNo("商户网站唯一订单号");
		alipayAuth.setTotalFee("交易金额");

		Map<String, String> param = getAuthParam(alipayAuth);
		// 拼接后字符串
		String prestr = PayUtils.createLinkString(param);

		// sign签名
		alipayAuth.setSign(getSign(prestr, alipayAuth.getKey(), alipayAuth.getInputCharset()));

		// 通过授权接口获取token
		// 1.拼接url字符串
		StringBuffer urlStr = new StringBuffer();
		urlStr.append(alipayAuth.getAlipayGatewayNew()).append(prestr).append("&sign=" + alipayAuth.getSign());
		// 2.获取token
		return getToken(urlStr.toString(), alipayAuth.getInputCharset());
	}

private static Map<String, String> getAuthParam(AlipayAuth alipayAuth) {
		Map<String, String> param = new HashMap<String, String>();
		param.put("service", alipayAuth.getService());
		param.put("partner", alipayAuth.getPartner());
		param.put("_input_charset", alipayAuth.getInputCharset());
		param.put("sec_id", alipayAuth.getSecId());
		param.put("format", alipayAuth.getFormat());
		param.put("v", alipayAuth.getV());
		param.put("req_id", alipayAuth.getReqId());
		param.put("req_data", alipayAuth.getReqData());
		return PayUtils.paraFilter(param);
	}

public static Map<String, String> paraFilter(Map<String, String> sArray) {

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

        if (sArray == null || sArray.size() <= 0) {
            return result;
        }

        for (String key : sArray.keySet()) {
            String value = sArray.get(key);
            if (value == null || value.equals("") || key.equalsIgnoreCase("sign")
                || key.equalsIgnoreCase("sign_type")) {
                continue;
            }
            result.put(key, value);
        }

        return result;
    }