Java后台编写微信扫码支付

因业务需求，需要简单实现让用户扫描微信二维码完成支付，于是查阅资料，做了一个LB一点的支付，大致流程是前端调用接口，完成订单创建，并调用支付接口，生成二维码，用户扫描二维码支付成功，刷新页面，完成整个支付流程，代码如下：

接口部分：

@ApiOperation(value = "创建订单")
    @PostMapping("/createOrder")
    public Result createOrder(Integer order_price,String organizationId){
        try {
            if(order_price == 0){
                return ResultGenerator.genFailedResult(201, "充值金额为空");
            }
            String orderId = PayCommonUtils.getCurrTime() + PayCommonUtils.buildRandom(4); // 商户订单号
            //创建订单
            OrganizationOrder organizationOrder = new OrganizationOrder();
            organizationOrder.setOrganizationID(organizationId);
            organizationOrder.setOrderTime(DateUtil.formatDateTime(new Date()));
            if(order_price != 0){
                BigDecimal b = new BigDecimal(order_price);
                float f = b.floatValue();
                organizationOrder.setPrice(f);
            }
            organizationOrder.setOrderNo(orderId);
            organizationOrder.setChannel(2);
            organizationOrder.setPayState(0);
            organizationOrder.setComment("充值"+order_price+"元");
            int i = organizationOrderService.insertOrganizationOrder(organizationOrder);
            if(i>0){
                return ResultGenerator.genOkResult(orderId);
            }
            return ResultGenerator.genFailedResult(500, "创建订单失败！");
        } catch (Exception e) {
            log.error("查询订单异常", e);
            return ResultGenerator.genFailedResult(500, "系统异常");
        }
    }
	
	/**
	*将创建好的订单id传到支付接口，调用微信接口
	*
	**/
 	@ApiOperation(value = "微信支付")
    @GetMapping("/unifiedorder")
    public Result unifiedorder(String orderId, HttpServletRequest request,HttpServletResponse response){
        try {
            if(orderId == null){
                return ResultGenerator.genFailedResult(201, "订单号为空！");
            }
            OrganizationOrder order = organizationOrderService.selectOrganizationOrderByOrderNo(orderId);
            if(order != null){
            	//调用微信支付接口，创建预付订单
                Map map= GetWeixinUrlUtil.weixin_pay(order.getPrice().intValue(),orderId,request);
                String urlCode = (String) map.get("code_url");         
				//将微信接口生成的二维码接口传入，利用Google开源方法生成二维码，二维码处理成流文件直接输出到页面的图片文件
                GetWeixinUrlUtil.encodeQrcode(urlCode,response);
            }
            return null;
        } catch (Exception e) {
            log.error("查询订单异常", e);
            return ResultGenerator.genFailedResult(500, "系统异常");
        }
    }
    //微信回调地址，验证是否支付成功
	@PostMapping("/notify")
    @ResponseBody
    public Result payWexin(HttpServletRequest request, HttpServletResponse response){

        try {
            return ResultGenerator.genOkResult(weixinNotifyService.weixin_notify(request,response));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ResultGenerator.genFailedResult(500, "系统异常");
    }

	//微信没有回调成功页面，所以页面要做一个轮询，隔几秒查一下是否支付成功
    @PostMapping("/selectOrganizationOrderByOrderNo")
    public Result selectOrganizationOrderByOrderNo(String orderId){
        try {
            if(orderId == null){
                return ResultGenerator.genFailedResult(201, "订单号为空");
            }
            OrganizationOrder order = organizationOrderService.selectOrganizationOrderByOrderNo(orderId);
            if(order != null){
                if(order.getPayState() == 1){
                    return ResultGenerator.genOkResult("支付成功！");
                }
                return ResultGenerator.genFailedResult(201,"未支付");
            }
            return ResultGenerator.genFailedResult(202, "未生成订单！");
        } catch (Exception e) {
            log.error("查询订单异常", e);
            return ResultGenerator.genFailedResult(500, "系统异常");
        }
    }

调用的工具类：

import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import org.apache.commons.lang.StringUtils;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.*;

public class GetWeixinUrlUtil {

    private static final int BLACK = 0xff000000;
    private static final int WHITE = 0xFFFFFFFF;

    //获取二维码url
    public static Map weixin_pay(int order_price,String out_trade_no, HttpServletRequest request) throws Exception {
        // 账号信息
        String appid = PayConfigUtils.APP_ID;  // appid
        String mch_id = PayConfigUtils.MCH_ID; // 商户号
        String key = PayConfigUtils.API_KEY; // key
        String currTime = PayCommonUtils.getCurrTime();
        String strTime = currTime.substring(8, currTime.length());
        String strRandom = PayCommonUtils.buildRandom(4) + "";
        String nonce_str = strTime + strRandom;
        //int order_price = 1; // 商品价格   注意：价格的单位是分
        String body = "";   // 商品名称
        // 获取发起电脑 ip
        String spbill_create_ip = PayConfigUtils.getIP(request);
        // 回调接口
        String notify_url = PayConfigUtils.NOTIFY_URL;
        String trade_type = "NATIVE";  //交易类型
        //超时时间
        String timeExpire = getOrderExpireTime(2*60*1000L);
        System.out.print("二维码失效时间："+timeExpire);
        SortedMap<Object,Object> packageParams = new TreeMap<Object,Object>();
        packageParams.put("appid", appid);
        packageParams.put("mch_id", mch_id);
        packageParams.put("nonce_str", nonce_str);
        packageParams.put("body", body);
        packageParams.put("out_trade_no", out_trade_no);
        packageParams.put("total_fee", String.valueOf(order_price*100));
        packageParams.put("spbill_create_ip", spbill_create_ip);
        packageParams.put("notify_url", notify_url);
        packageParams.put("trade_type", trade_type);
        packageParams.put("time_expire",timeExpire);
        //生成签名
        String sign = PayCommonUtils.createSign("UTF-8", packageParams,key);
        packageParams.put("sign", sign);

        String requestXML = PayCommonUtils.getRequestXml(packageParams);
        System.out.println(requestXML);

        String resXml = Https.postData(PayConfigUtils.UFDODER_URL, requestXML);
        Map map = XmlUtils.doXMLParse(resXml);
        map.put("out_trade_no",out_trade_no);
        map.put("total_fee",String.valueOf(order_price));
        String urlCode = (String) map.get("code_url");
        System.out.println(urlCode);
        return map;
    }

    /**
     * 设置微信二维码失效时间，并返回具体失效的时间点
     * @param expire 二维码的有效时间，单位是毫秒
     * @return
     */
    public static String getOrderExpireTime(Long expire){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
        Date now = new Date();
        Date afterDate = new Date(now .getTime() + expire);
        return sdf.format(afterDate );
    }

    // 特殊字符处理
    public static String UrlEncode(String src)  throws UnsupportedEncodingException {
        return URLEncoder.encode(src, "UTF-8").replace("+", "%20");
    }

    /**
     * 将路径生成二维码图片
     * @author xiaoloutingyu
     * @param content
     * @param response
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static void encodeQrcode(String content, HttpServletResponse response){
        response.setDateHeader("Expires", 0);
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        response.setHeader("Pragma", "no-cache");
        response.setContentType("image/jpeg");
        ServletOutputStream out = null;
        if(StringUtils.isBlank(content)){
            return;
        }
        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        Map hints = new HashMap();
        BitMatrix bitMatrix = null;
        try {
            bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 250, 250,hints);
            BufferedImage image = toBufferedImage(bitMatrix);
            //输出二维码图片流
            try {
                out = response.getOutputStream();
                ImageIO.write(image, "png", out);
                out.flush();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (WriterException e1) {
            e1.printStackTrace();
        }finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 类型转换
     * @author xiaoloutingyu
     * @param matrix
     * @return
     */
    public static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) == true ? BLACK : WHITE);
            }
        }
        return image;
    }
}

http请求：

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.net.URLConnection;

public class Https {
    //用http连接提交支付信息参数
    private static final Log logger = LogFactory.getLog("org.apache.catalina.tribes.MESSAGES" );

    private final static int CONNECT_TIMEOUT = 5000; // in milliseconds

    private final static String DEFAULT_ENCODING = "UTF-8";

    public static String postData(String urlStr, String data){
        return postData(urlStr, data, null);
    }

    public static String postData(String urlStr, String data, String contentType){
        BufferedReader reader = null;
        try {
            URL url = new URL(urlStr);
            URLConnection conn = url.openConnection();
            conn.setDoOutput(true);
            conn.setConnectTimeout(CONNECT_TIMEOUT);
            conn.setReadTimeout(CONNECT_TIMEOUT);
            if(contentType != null)
                conn.setRequestProperty("content-type", contentType);
            OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream(), DEFAULT_ENCODING);
            if(data == null)
                data = "";
            writer.write(data);
            writer.flush();
            writer.close();

            reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), DEFAULT_ENCODING));
            System.out.println(reader.toString());
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
                sb.append("\r\n");
            }
            return sb.toString();
        } catch (IOException e) {
            logger.error("Error connecting to " + urlStr + ": " + e.getMessage());
        } finally {
            try {
                if (reader != null)
                    reader.close();
            } catch (IOException e) {
            }
        }
        return null;
    }
}

Md5加密：

import java.security.MessageDigest;

public class Md5 {
    //md5加密
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))

                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));

            else
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));

        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };


}

调用微信支付过程

import java.text.SimpleDateFormat;
import java.util.*;

public class PayCommonUtils {

    /**
     * 是否签名正确,规则是:按参数名称a-z排序,遇到空值的参数不参加签名。
     * @return boolean
     */
    public static boolean isTenpaySign(String characterEncoding, SortedMap<Object, Object> packageParams, String API_KEY) {
        StringBuffer sb = new StringBuffer();
        Set es = packageParams.entrySet();
        Iterator it = es.iterator();
        while(it.hasNext()) {
            Map.Entry entry = (Map.Entry)it.next();
            String k = (String)entry.getKey();
            String v = (String)entry.getValue();
            if(!"sign".equals(k) && null != v && !"".equals(v)) {
                sb.append(k + "=" + v + "&");
            }
        }

        sb.append("key=" + API_KEY);

        //算出摘要
        String mysign = Md5.MD5Encode(sb.toString(), characterEncoding).toLowerCase();
        String tenpaySign = ((String)packageParams.get("sign")).toLowerCase();

        //System.out.println(tenpaySign + "    " + mysign);
        return tenpaySign.equals(mysign);
    }

    /**
     * @author  xiaoloutingyu
     * @date 2016-4-22
     * @Description：sign签名
     * @param characterEncoding
     *            编码格式
     * @param
     *
     * @return
     */

    public static String createSign(String characterEncoding, SortedMap<Object, Object> packageParams, String API_KEY) {
        StringBuffer sb = new StringBuffer();
        Set es = packageParams.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) {
                sb.append(k + "=" + v + "&");
            }
        }
        sb.append("key=" + API_KEY);
        String sign = Md5.MD5Encode(sb.toString(), characterEncoding).toUpperCase();
        return sign;
    }
    /**
     65      * @author  xiaoloutingyu
     66      * @date 2016-4-22
     67      * @Description：将请求参数转换为xml格式的string
     68      * @param parameters
     69      *            请求参数
     70      * @return
     71      */

    public static String getRequestXml(SortedMap<Object, Object> parameters) {
        StringBuffer sb = new StringBuffer();
        sb.append("<xml>");
        Set es = parameters.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            if ("attach".equalsIgnoreCase(k) || "body".equalsIgnoreCase(k) || "sign".equalsIgnoreCase(k)) {
                sb.append("<" + k + ">" + "<![CDATA[" + v + "]]></" + k + ">");
            } else {
                sb.append("<" + k + ">" + v + "</" + k + ">");
            }
        }
        sb.append("</xml>");
        return sb.toString();
    }
    /**
     92      * 取出一个指定长度大小的随机正整数.
     93      *
     94      * @param length
     95      *            int 设定所取出随机数的长度。length小于11
     96      * @return int 返回生成的随机数。
     97      */
    public static int buildRandom(int length) {
        int num = 1;
        double random = Math.random();
        if (random < 0.1) {
            random = random + 0.1;
        }
        for (int i = 0; i < length; i++) {
            num = num * 10;
        }
        return (int) ((random * num));
    }

    /**
     111      * 获取当前时间 yyyyMMddHHmmss
     112      *
     113      * @return String
     114      */
    public static String getCurrTime() {
        Date now = new Date();
        SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");
        String s = outFormat.format(now);
        return s;
    }

}

微信支付需要的参数：

import javax.servlet.http.HttpServletRequest;

public class PayConfigUtils {
    //这里的必要参数填写自己的，另外回调地址必须是外网能访问的，我这里是用netapp开通了一个隧道，免费的，大家测试的时候也可以申请个，可以百度netapp教程几分钟学习一下就可以
    public static final String APP_ID = "";//微信开发平台应用ID(公众号ID)
    public static final String MCH_ID = "";//商户号(商户号ID)
    public static final String API_KEY = "";//API key(商户号里面的)
    public static final String CREATE_IP = "";//发起支付的ip
    public static final String NOTIFY_URL = "https://xxxx/pay/notify";//回调地址
    public static final String UFDODER_URL = "https://api.mch.weixin.qq.com/pay/unifiedorder";//微信统一下单接口
    public static final String APP_SECRET = "";//应用对应的凭证(在公众号里面)

    //获取ip
    public static String getIP(HttpServletRequest request)
    {
        String ip = request.getRemoteAddr();
        return ip;
    }
}

xml解析：

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

public class XmlUtils {
    /**
     * 解析xml,返回第一级元素键值对。如果第一级元素有子节点，则此节点的值是子节点的xml数据。
     * @param strxml
     * @return
     * @throws JDOMException
     * @throws IOException
     */

    public static Map doXMLParse(String strxml) throws JDOMException, IOException {
        strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");

        if(null == strxml || "".equals(strxml)) {
            return null;
        }

        Map m = new HashMap();

        InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8"));
        SAXBuilder builder = new SAXBuilder();
        Document doc = builder.build(in);
        Element root = doc.getRootElement();
        List list = root.getChildren();
        Iterator it = list.iterator();
        while(it.hasNext()) {
            Element e = (Element) it.next();
            String k = e.getName();
            String v = "";
            List children = e.getChildren();
            if(children.isEmpty()) {
                v = e.getTextNormalize();
            } else {
                v = XmlUtils.getChildrenText(children);
            }

            m.put(k, v);
        }

        //关闭流
        in.close();

        return m;
    }

    /**
     59      * 获取子结点的xml
     60      * @param children
     61      * @return String
     62      */

    public static String getChildrenText(List children) {
        StringBuffer sb = new StringBuffer();
        if(!children.isEmpty()) {
            Iterator it = children.iterator();
            while(it.hasNext()) {
                Element e = (Element) it.next();
                String name = e.getName();
                String value = e.getTextNormalize();
                List list = e.getChildren();
                sb.append("<" + name + ">");
                if(!list.isEmpty()) {
                    sb.append(XmlUtils.getChildrenText(list));
                }
                sb.append(value);
                sb.append("</" + name + ">");
            }
        }

        return sb.toString();
    }
}

回调接口：

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public interface WeixinNotifyService {

    public int weixin_notify(HttpServletRequest request, HttpServletResponse response) throws Exception;
}

接口实现：

import com.shineyoo.common.pay.PayCommonUtils;
import com.shineyoo.common.pay.PayConfigUtils;
import com.shineyoo.common.pay.XmlUtils;
import com.shineyoo.edu.account.domain.OrganizationAccount;
import com.shineyoo.edu.account.service.IOrganizationAccountService;
import com.shineyoo.edu.organizationOrder.domain.OrganizationOrder;
import com.shineyoo.edu.organizationOrder.service.IOrganizationOrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.util.*;

/**
 * @author Administrator
 */
@Service
public class WeixinNotifyImpl implements WeixinNotifyService {

    @Autowired
    private IOrganizationOrderService organizationOrderService;
    @Autowired
    private IOrganizationAccountService organizationAccountService;

    @Override
    public int weixin_notify(HttpServletRequest request, HttpServletResponse response) throws Exception {

        System.out.println("调用回调方法");
        int flag = 1;
        //读取参数
        InputStream inputStream ;
        StringBuffer sb = new StringBuffer();
        inputStream = request.getInputStream();
        String s ;
        BufferedReader in = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
        while ((s = in.readLine()) != null){
            sb.append(s);
        }
        in.close();
        inputStream.close();

        //解析xml成map
        Map<String, String> m = new HashMap<String, String>();
        m = XmlUtils.doXMLParse(sb.toString());

        //过滤空 设置 TreeMap
        SortedMap<Object,Object> packageParams = new TreeMap<Object,Object>();
        Iterator it = m.keySet().iterator();
        while (it.hasNext()) {
            String parameter = (String) it.next();
            String parameterValue = m.get(parameter);

            String v = "";
            if(null != parameterValue) {
                v = parameterValue.trim();
            }
            packageParams.put(parameter, v);
        }

        // 账号信息
        String key = PayConfigUtils.API_KEY; // key

        //logger.info(packageParams);
        System.out.println(packageParams);
        //判断签名是否正确
        if(PayCommonUtils.isTenpaySign("UTF-8", packageParams,key)) {
            //------------------------------
            //处理业务开始
            //------------------------------
            String resXml = "";
            if("SUCCESS".equals((String) packageParams.get("result_code"))){
                flag = 0;
                // 这里是支付成功
                //执行自己的业务逻辑
                String mch_id = (String) packageParams.get("mch_id");
                String openid = (String) packageParams.get("openid");
                String is_subscribe = (String) packageParams.get("is_subscribe");
                String out_trade_no = (String) packageParams.get("out_trade_no");
                String total_fee = (String) packageParams.get("total_fee");
                String cash_fee_s = (String) packageParams.get("cash_fee");
                String cash_fee = String.valueOf(Integer.parseInt(cash_fee_s) / 100);
                //String time_end = MctsUtils.numberDateToDate((String) packageParams.get("time_end"));
                String transaction_id = (String) packageParams.get("transaction_id");

                System.out.print("订单ID为：------"+out_trade_no);
                //更新订单状态为 已支付
                

                System.out.println("支付成功 ,处理业务成功");
                //logger.info("支付成功");
                //通知微信.异步确认成功.必写.不然会一直通知后台.八次之后就认为交易失败了.
                resXml = "<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>" + "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> ";
                //------------------------------
                //处理业务完毕
                //------------------------------
                //向微信服务器发送确认信息，若不发送，微信服务器会间隔不同的时间调用回调方法
                BufferedOutputStream out = new BufferedOutputStream(
                        response.getOutputStream());
                out.write(resXml.getBytes());
                out.flush();
                out.close();
                System.out.println("通知微信.异步确认成功");
            } else {
                System.out.println("支付失败,错误信息：" + packageParams.get("err_code"));
                // logger.info("支付失败,错误信息：" + packageParams.get("err_code"));
                resXml = "<xml>" + "<return_code><![CDATA[FAIL]]></return_code>"
                        + "<return_msg><![CDATA[报文为空]]></return_msg>" + "</xml> ";

                BufferedOutputStream out = new BufferedOutputStream(
                        response.getOutputStream());
                out.write(resXml.getBytes());
                out.flush();
                out.close();
                System.out.println("执行回调函数失败");
            }
        } else{
            //logger.info("通知签名验证失败");
            System.out.println("通知签名验证失败");
        }
        return flag;
    }
}

要引入谷歌的一个生成图片的包

		<dependency>
			<groupId>com.google.zxing</groupId>
			<artifactId>core</artifactId>
			<version>3.3.0</version>
			<scope>compile</scope>
		</dependency>

调用轮询的方法，这里用搜狐的一个方法，还有其他的，可以百度

<script src="http://pv.sohu.com/cityjson?ie=utf-8"></script>
window.setInterval("查询方法",1500);

大至流程就是这样的，有什么需要改进的地方，大家可以留言！