支付宝当面付（条码支付）功能开发

• 商家通过扫描线下买家支付宝钱包中的条码、二维码等方式将买家的交易资金直接打入卖家支付宝账户，资金实时到账；
  
• 线下买家通过使用支付宝钱包扫描商家的二维码等方式完成支付，提升商家收银效率，资金实时到账；
  
• 线下买家使用支付宝钱包中的当面付功能，通过声波支付的方式向商家完成付款，资金实时到账。
  

//实例化客户端
AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do", APP_ID, APP_PRIVATE_KEY, "json", CHARSET, ALIPAY_PUBLIC_KEY, "RSA2");
//实例化具体API对应的request类,类名称和接口名称对应,当前调用接口名称：alipay.open.public.template.message.industry.modify 
AlipayOpenPublicTemplateMessageIndustryModifyRequest request = new AlipayOpenPublicTemplateMessageIndustryModifyRequest();
//SDK已经封装掉了公共参数，这里只需要传入业务参数
//此次只是参数展示，未进行字符串转义，实际情况下请转义
request.setBizContent("  {" +
"    \"primary_industry_name\":\"IT科技/IT软件与服务\"," +
"    \"primary_industry_code\":\"10001/20102\"," +
"    \"secondary_industry_code\":\"10001/20102\"," +
"    \"secondary_industry_name\":\"IT科技/IT软件与服务\"" +
" }");
AlipayOpenPublicTemplateMessageIndustryModifyResponse response = alipayClient.execute(request); 
//调用成功，则处理业务逻辑
if(response.isSuccess()){
    //.....
}

#应用id，要求应用上线，且其下功能签约状态为生效
appId=20110906...78327
#应用私钥（appId所属应用的应用私钥）RSA2加密方式
privateKey=MIIEvgI...oC6/I2xPqZnvhbntS5qi1NwYg2
#支付宝公钥
alipayPublicKey=MIIBI...wIDAQAB

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
/**
 * 支付宝API类
 */
public class AlipayAPI {
    /** 应用ID */
    private static String appId;
    /** 应用私钥 */
    private static String privateKey;
    /** 支付宝公钥 */
    private static String alipayPublicKey;
    /** 支付调用接口 */
    private static final String url_pay = "https://openapi.alipay.com/gateway.do";
    static {
        InputStream is = AlipayAPI.class.getResourceAsStream("/alipay.properties");
        Properties prop = new Properties();
        try {
            prop.load(is);
            setAppId(prop.getProperty("appId"));
            setPrivateKey(prop.getProperty("privateKey"));
            setAlipayPublicKey(prop.getProperty("alipayPublicKey"));
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static String getAppId() {
        return appId;
    }
    public static void setAppId(String appId) {
        AlipayAPI.appId = appId;
    }
    public static String getPrivateKey() {
        return privateKey;
    }
    public static void setPrivateKey(String privateKey) {
        AlipayAPI.privateKey = privateKey;
    }
    public static String getAlipayPublicKey() {
        return alipayPublicKey;
    }
    public static void setAlipayPublicKey(String alipayPublicKey) {
        AlipayAPI.alipayPublicKey = alipayPublicKey;
    }
    public static String getUrl_pay() {
        return url_pay;
    }
}

/**
 * 统一收单交易支付的参数封装类
 */
public class PayParam {
    /** 商户订单 */
    private String out_trade_no;
    /** 支付场景 */
    private String scene;
    /** 支付授权码，即用户的付款码 */
    private String auth_code;
    /** 订单标题 */
    private String subject;
    /** 订单金额 */
    private double total_amount;
    public PayParam(String out_trade_no, String subject, double total_amount, String auth_code) {
        this.out_trade_no = out_trade_no;
        this.subject = subject;
        this.total_amount = total_amount;
        this.auth_code = auth_code;
    }
    public String getOut_trade_no() {
        return out_trade_no;
    }
    public void setOut_trade_no(String out_trade_no) {
        this.out_trade_no = out_trade_no;
    }
    public String getScene() {
        return scene;
    }
    public void setScene(String scene) {
        this.scene = scene;
    }
    public String getAuth_code() {
        return auth_code;
    }
    public void setAuth_code(String auth_code) {
        this.auth_code = auth_code;
    }
    public String getSubject() {
        return subject;
    }
    public void setSubject(String subject) {
        this.subject = subject;
    }
    public double getTotal_amount() {
        return total_amount;
    }
    public void setTotal_amount(double total_amount) {
        this.total_amount = total_amount;
    }
}

import com.alibaba.fastjson.JSON;
import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.alipay.api.request.AlipayTradePayRequest;
import com.alipay.api.response.AlipayTradePayResponse;
import java.util.Date;
/**
 * 支付宝的工具类
 */
public class AlipayUtil {
    /** UTF8编码格式 */
    private static final String CHARSET_UTF8 = "UTF-8";
    /** 加密方式 */
    private static final String SIGN_TYPE = "RSA2";
    /** 数据格式 */
    private static final String FORMAT = "JSON";
    /** 支付场景，条码支付 */
    private static final String SCENE_BARCODE = "bar_code";
    /**
     * 当面付（条码支付）
     * @param content
     * @return
     */
    public static AlipayTradePayResponse barCodePay(PayParam content){
        AlipayClient client = new DefaultAlipayClient(AlipayAPI.getUrl_pay(), AlipayAPI.getAppId(),
                AlipayAPI.getPrivateKey(), FORMAT, CHARSET_UTF8, AlipayAPI.getAlipayPublicKey(), SIGN_TYPE);
        AlipayTradePayRequest request = new AlipayTradePayRequest();
        content.setScene(SCENE_BARCODE);
        String bizContent = JSON.toJSONString(content);
        request.setBizContent(bizContent);
        AlipayTradePayResponse response = null;
        try {
            response = client.execute(request);
        } catch (AlipayApiException e) {
            e.printStackTrace();
        }
        return response;
    }
    /**
     * 支付完成后的业务处理
     * @param response
     */
    public static void afterBarCodePay(AlipayTradePayResponse response) {
        if (response.isSuccess()) {
            //处理业务逻辑
            System.out.println("start handle business");
        }
    }
    /**
     * 获取商户订单
     * @return
     */
    public static String getTradeNo() {
        return "PAY" + new Date().getTime();
    }
    //测试
    public static void main(String[] args) {
        String tradeNo = getTradeNo();
        String subject = "测试用订单";
        double totalAmount = 0.01;
        String authCode = "274726044141298157";
        PayParam param = new PayParam(tradeNo, subject, totalAmount, authCode);
        AlipayTradePayResponse response = barCodePay(param);
        System.out.println(response.getBody());
        afterBarCodePay(response);
    }
}