java微信扫码支付Native（模式二）

官方开发文档模式二的地址：https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=6_5

pom文件的依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wky</groupId>
    <artifactId>wechat</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>wechat</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--微信扫码支付所需要的依赖-->
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.2.1</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>net.sf.ezmorph</groupId>
            <artifactId>ezmorph</artifactId>
            <version>1.0.6</version>
        </dependency>
        <!--jsp-->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.2.3</version>
            <classifier>jdk15</classifier><!-- 指定jdk版本 -->
        </dependency>
        <dependency>
            <groupId>com.github.wxpay</groupId>
            <artifactId>wxpay-sdk</artifactId>
            <version>0.0.3</version>
        </dependency>
        <!-- fastjson-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.24</version>
        </dependency>

        <!-- gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.thoughtworks.xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.4.4</version>
        </dependency>
        <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <version>3.0</version>
        </dependency>

        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>
        <dependency>
            <groupId>org.jdom</groupId>
            <artifactId>jdom</artifactId>
            <version>1.1</version>
        </dependency>
        <dependency>
            <groupId>com.orhanobut</groupId>
            <artifactId>logger</artifactId>
            <version>1.14</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.25</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.25</version>
            <scope>test</scope>
        </dependency>
        <!--屏蔽自带的tomcat-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.4</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

PayCommonUtil.java  微信支付常用方法

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;

public class PayCommonUtil
{
    /**
     * 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 = MD5Util.MD5Encode(sb.toString(), characterEncoding).toLowerCase();
        String tenpaySign = ((String)packageParams.get("sign")).toLowerCase();  

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

    /**
     * @author
     * @date 2016-4-22
     * @Description：sign签名
     * @param characterEncoding
     *            编码格式
     * @param parameters
     *            请求参数
     * @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 = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase();
        return sign;
    }  

    /**
     * @author
     * @date 2016-4-22
     * @Description：将请求参数转换为xml格式的string
     * @param parameters
     *            请求参数
     * @return
     */
    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();
    }  

    /**
     * 取出一个指定长度大小的随机正整数.
     *
     * @param length
     *            int 设定所取出随机数的长度。length小于11
     * @return int 返回生成的随机数。
     */
    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));
    }  

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

XMLUtil.java   将支付参数转换为xml格式

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;

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

public class XMLUtil
{
    /**
     * 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 = XMLUtil.getChildrenText(children);
            }  

            m.put(k, v);
        }  

        //关闭流
        in.close();  

        return m;
    }  

    /**
     * 获取子结点的xml
     * @param children
     * @return String
     */
    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(XMLUtil.getChildrenText(list));
                }
                sb.append(value);
                sb.append("</" + name + ">");
            }
        }  

        return sb.toString();
    }
}

HttpUtil.java  用http连接提交支付信息参数

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

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

public class HttpUtil
{
    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;
    }
}

MD5Util.java   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];
    }  

    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" };
}

GetWeixinUrlUtil.java   获取订单生成的二维码URL

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

public class GetWeixinUrlUtil
{
    //获取二维码url
    public static String weixin_pay(String ip, VcWeixinPay vcWeixinPay) throws Exception {
    // 账号信息
        String appid = PayConfigUtil.APP_ID;  // appid
        String mch_id = PayConfigUtil.MCH_ID; // 商户号
        String key = PayConfigUtil.API_KEY; // key
        String currTime = PayCommonUtil.getCurrTime();
        String strTime = currTime.substring(8, currTime.length());
        String strRandom = PayCommonUtil.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";   // 商品名称
        String out_trade_no = PayCommonUtil.getCurrTime() + PayCommonUtil.buildRandom(4); // 商户订单号
        // 获取发起电脑 ip
        String spbill_create_ip = ip;
        // 回调接口
        String notify_url = PayConfigUtil.NOTIFY_URL;
        String trade_type = "NATIVE";  //交易类型
        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));
        packageParams.put("spbill_create_ip", spbill_create_ip);
        packageParams.put("notify_url", notify_url);
        packageParams.put("trade_type", trade_type);
        //生成签名
        String sign = PayCommonUtil.createSign("UTF-8", packageParams,key);
        packageParams.put("sign", sign);  

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

        String resXml = HttpUtil.postData(PayConfigUtil.UFDODER_URL, requestXML);
        Map map = XMLUtil.doXMLParse(resXml);
        String urlCode = (String) map.get("code_url");  

        return urlCode;
    } 

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

PayConfigUtil.java  微信支付参数

import javax.servlet.http.HttpServletRequest;

public class PayConfigUtil
{
    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 = "";//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;
    }

支付回调方法

public void weixin_notify(HttpServletRequest request,HttpServletResponse response) throws Exception
    {
        System.out.println("调用回调方法");
        //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 = XMLUtil.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 = PayConfigUtil.API_KEY; // key  

        logger.info(packageParams);
        //判断签名是否正确
        if(PayCommonUtil.isTenpaySign("UTF-8", packageParams,key)) {
            //------------------------------
            //处理业务开始
            //------------------------------
            String resXml = "";
            if("SUCCESS".equals((String) packageParams.get("result_code"))){
                // 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");

                    //////////执行自己的业务逻辑（报存订单信息到数据库）////////////////
                    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 {
                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");
        }
    }

@RequestMapping(value="/image",method = RequestMethod.GET)
public void payWexin(@RequestParam String ip, HttpServletResponse response)throws Exception{
String url=GetWeixinUrlUtil.weixin_pay(ip);
GetWeixinUrlUtil.encodeQrcode(url,response);

根据GetWeixinUrlUtil.java获取到微信支付订单信息的二维码url，下载一个解析二维码的js插件（jquery.qrcode.min.js），把获取到二维码url在前端页面用jquery.qrcode.min.js解析，就能显示二维码了。
　　前端页面简略代码：

<script type="text/javascript" src="js/jquery.qrcode.min.js"></script>
<script language="javascript">
    $(function(){
        var codeUrl = ${erWeiMa};//erWeiMa是后端传的二维码url
        $("#code").qrcode({
            render: "canvas", //table方式
            width: 240, //宽度
            height:240, //高度
            text: codeUrl //任意内容
        });
    });
</script>

<div id="code" style="width: 240px;height: 240px;margin: 0px auto;"></div>