Java实现微信扫码支付---方式二

话不多说直接上代码：

我这里将有关微信支付的代码都放到了util包下面。以下代码亲测可用。附上原文链接：https://blog.csdn.net/chen_pan_pan/article/details/71433679
HttpUtil：

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.log4j.Logger;  


/** 
 * http请求工具类 
 * @author chenp 
 * 
 */  
public class HttpUtil {  

    private final static int CONNECT_TIMEOUT = 5000; // in milliseconds  连接超时的时间  
    private final static String DEFAULT_ENCODING = "UTF-8";  //字符串编码  
    private static Logger lg=Logger.getLogger(HttpUtil.class);  

    public static String postData(String urlStr, String data){    
        return postData(urlStr, data, null);    
    }    
    /** 
     * post数据请求 
     * @param urlStr 
     * @param data 
     * @param contentType 
     * @return 
     */  
    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));    
            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) {    
        lg.info("Error connecting to " + urlStr + ": " + e.getMessage());    
        } finally {    
            try {    
                if (reader != null)    
                    reader.close();    
            } catch (IOException e) {    
            }    
        }    
        return null;    
    }    
}    

MD5Util：

import java.security.MessageDigest;  
/** 
 * Md5加密类 
 * @author chenp 
 * 
 */  
public class MD5Util {  

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();    
    }    

    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" };    

}  

PayForUtil ：

import java.net.Inet4Address;  
import java.net.InetAddress;  
import java.net.InterfaceAddress;  
import java.net.NetworkInterface;  
import java.net.SocketException;  
import java.text.SimpleDateFormat;  
import java.util.Date;  
import java.util.Enumeration;  
import java.util.Iterator;  
import java.util.List;  
import java.util.Map;  
import java.util.Set;  
import java.util.SortedMap;  


import org.apache.log4j.Logger;  


public class PayForUtil {  

private static Logger lg=Logger.getLogger(PayForUtil.class);  

/**  
     * 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();    

        return tenpaySign.equals(mysign);    
    }    

    /**  
     * @author chenp 
     * @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 chenp 
     * @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  
     *  @author chenp 
     * @return String  
     */    
    public static String getCurrTime() {    
        Date now = new Date();    
        SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");    
        String s = outFormat.format(now);    
        return s;    
    }  
    /** 
     * 获取本机IP地址 
     * @author chenp 
     * @return 
     */  
    public static String localIp(){  
        String ip = null;  
        Enumeration allNetInterfaces;  
        try {  
            allNetInterfaces = NetworkInterface.getNetworkInterfaces();              
            while (allNetInterfaces.hasMoreElements()) {  
                NetworkInterface netInterface = (NetworkInterface) allNetInterfaces.nextElement();  
                List<InterfaceAddress> InterfaceAddress = netInterface.getInterfaceAddresses();  
                for (InterfaceAddress add : InterfaceAddress) {  
                    InetAddress Ip = add.getAddress();  
                    if (Ip != null && Ip instanceof Inet4Address) {  
                        ip = Ip.getHostAddress();  
                    }  
                }  
            }  
        } catch (SocketException e) {  
        lg.warn("获取本机Ip失败:异常信息:"+e.getMessage());  
        }  
        return ip;  
    }  

}  

WeChatConfig ：
说明：此类与原文相比稍作了修改，大家也可以根据自己需要修改相关代码。

import com.iptop.service.base.ConfigProperties;  


/** 
 * 微信支付配置文件 
 * @author chenp 
 * 
 */  
public class WeChatConfig {  

/** 
* 微信服务号APPID 
*/  
public static String APPID="";  
/** 
* 微信支付的商户号 
*/  
public static String MCHID="";  
/** 
* 微信支付的API密钥 
*/  
public static String APIKEY="";  
/** 
* 微信支付成功之后的回调地址【注意：当前回调地址必须是公网能够访问的地址】 
*/  
public static String WECHAT_NOTIFY_URL_PC="";   
/** 
* 微信统一下单API地址 
*/  
public static String UFDODER_URL="https://api.mch.weixin.qq.com/pay/unifiedorder";  
/** 
* true为使用真实金额支付，false为使用测试金额支付（1分） 
*/  
public static String WXPAY="";  

}  

WeChatParams ：

/** 
 * 微信支付需要的一些参数 
 * @author chenp 
 * 
 */ 
 @Data//此注解代替了set、get方法，如果不想用这个注解也可以自己写set、get方法。 
public class WeChatParams {  

public String total_fee;//订单金额【备注：以分为单位】  
public String body;//商品名称  
public String out_trade_no;//商户订单号  
public String attach;//附加参数  
public String memberid;//会员ID  

}  

XMLUtil ：

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();    
    }    

}  

WeixinPay ：

import java.awt.image.BufferedImage;  
import java.io.IOException;  
import java.io.UnsupportedEncodingException;  
import java.net.URLEncoder;  
import java.util.HashMap;  
import java.util.Map;  
import java.util.SortedMap;  
import java.util.TreeMap;  
import javax.imageio.ImageIO;  
import javax.servlet.http.HttpServletResponse;  
import org.apache.commons.lang.StringUtils;  
import org.apache.log4j.Logger;  
import com.google.zxing.BarcodeFormat;  
import com.google.zxing.MultiFormatWriter;  
import com.google.zxing.WriterException;  
import com.google.zxing.common.BitMatrix;  


public class WeixinPay {  

public static Logger lg=Logger.getLogger(WeixinPay.class);  
private static final int BLACK = 0xff000000;  
private static final int WHITE = 0xFFFFFFFF;  

/** 
* 获取微信支付的二维码地址 
* @return 
* @author chenp 
* @throws Exception 
*/  
public static String getCodeUrl(WeChatParams ps) throws Exception {    
        /** 
         * 账号信息   
         */  
        String appid = WeChatConfig.APPID;//微信服务号的appid    
        String mch_id = WeChatConfig.MCHID; //微信支付商户号    
        String key = WeChatConfig.APIKEY; // 微信支付的API密钥    
        String notify_url = WeChatConfig.WECHAT_NOTIFY_URL_PC;//回调地址【注意，这里必须要使用外网的地址】       
        String ufdoder_url=WeChatConfig.UFDODER_URL;//微信下单API地址  
        String trade_type = "NATIVE"; //类型【网页扫码支付】  

        /** 
         * 时间字符串 
         */  
        String currTime = PayForUtil.getCurrTime();  
        String strTime = currTime.substring(8, currTime.length());    
        String strRandom = PayForUtil.buildRandom(4) + "";    
        String nonce_str = strTime + strRandom;    

        /** 
         * 参数封装 
         */  
        SortedMap<Object,Object> packageParams = new TreeMap<Object,Object>();    
        packageParams.put("appid", appid);    
        packageParams.put("mch_id", mch_id);  
        packageParams.put("nonce_str", nonce_str);//随机字符串  
        packageParams.put("body", ps.body);//支付的商品名称    
        packageParams.put("out_trade_no", ps.out_trade_no+nonce_str);//商户订单号【备注：每次发起请求都需要随机的字符串，否则失败。】  
        packageParams.put("total_fee", ps.total_fee);//支付金额  
        packageParams.put("spbill_create_ip", PayForUtil.localIp());//客户端主机  
        packageParams.put("notify_url", notify_url);  
        packageParams.put("trade_type", trade_type);  
        packageParams.put("attach", ps.attach);//额外的参数【业务类型+会员ID+支付类型】  


        String sign = PayForUtil.createSign("UTF-8", packageParams,key);  //获取签名  
        packageParams.put("sign", sign);    

        String requestXML = PayForUtil.getRequestXml(packageParams);//将请求参数转换成String类型    
        lg.info("微信支付请求参数的报文"+requestXML);    
        String resXml = HttpUtil.postData(ufdoder_url,requestXML);  //解析请求之后的xml参数并且转换成String类型  
        Map map = XMLUtil.doXMLParse(resXml);    
        lg.info("微信支付响应参数的报文"+resXml);   
        String urlCode = (String) map.get("code_url");    

        return urlCode;    
}    

  /** 
   * 将路径生成二维码图片 
   * @author chenp 
   * @param content 
   * @param response 
   */  
  @SuppressWarnings({ "unchecked", "rawtypes" })  
  public static void encodeQrcode(String content,HttpServletResponse response){  

      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 {  
             ImageIO.write(image, "png", response.getOutputStream());  
         } catch (IOException e) {  
             e.printStackTrace();  
         }  
     } catch (WriterException e1) {  
         e1.printStackTrace();  
     }           
 }  
  /** 
  * 类型转换 
  * @author chenp 
  * @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;  
}  
// 特殊字符处理    
public static String UrlEncode(String src)  throws UnsupportedEncodingException {    
   return URLEncoder.encode(src, "UTF-8").replace("+", "%20");    
}  

}  

最后还有一段支付后的回调代码。

/** 
* pc端微信支付之后的回调方法 
* @param request 
* @param response 
* @throws Exception 
*/  
    @RequestMapping(value="wechat_notify_url_pc",method=RequestMethod.POST)  
public void wechat_notify_url_pc(HttpServletRequest request,HttpServletResponse response) throws Exception{    

        //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<String> it = m.keySet().iterator();    
        while (it.hasNext()) {    
            String parameter = it.next();    
            String parameterValue = m.get(parameter);    

            String v = "";    
            if(null != parameterValue) {    
                v = parameterValue.trim();    
            }    
            packageParams.put(parameter, v);    
        }    
        // 微信支付的API密钥    
        String key = WeChatConfig.APIKEY; // key    

        lg.info("微信支付返回回来的参数："+packageParams);    
        //判断签名是否正确    
        if(PayForUtil.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开始  
            String app_id = (String)packageParams.get("appid");  
                String mch_id = (String)packageParams.get("mch_id");    
                String openid = (String)packageParams.get("openid");   
                String is_subscribe = (String)packageParams.get("is_subscribe");//是否关注公众号  

                //附加参数【商标申请_0bda32824db44d6f9611f1047829fa3b_15460】--【业务类型_会员ID_订单号】  
                String attach = (String)packageParams.get("attach");  
                //商户订单号  
                String out_trade_no = (String)packageParams.get("out_trade_no");    
                //付款金额【以分为单位】  
                String total_fee = (String)packageParams.get("total_fee");    
                //微信生成的交易订单号  
                String transaction_id = (String)packageParams.get("transaction_id");//微信支付订单号  
                //支付完成时间  
                String time_end=(String)packageParams.get("time_end");  

                lg.info("app_id:"+app_id);  
                lg.info("mch_id:"+mch_id);    
                lg.info("openid:"+openid);    
                lg.info("is_subscribe:"+is_subscribe);    
                lg.info("out_trade_no:"+out_trade_no);    
                lg.info("total_fee:"+total_fee);    
                lg.info("额外参数_attach:"+attach);   
                lg.info("time_end:"+time_end);   

                //执行自己的业务逻辑结束  
                lg.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> ";    

            } else {    
                lg.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> ";    
            }    
            //------------------------------    
            //处理业务完毕    
            //------------------------------    
            BufferedOutputStream out = new BufferedOutputStream(    
                    response.getOutputStream());    
            out.write(resXml.getBytes());    
            out.flush();    
            out.close();  
        } else{    
            lg.info("通知签名验证失败");    
        }    

    }  

因为采用的是微信扫码支付的第二种方式，这种方式较第一种业务逻辑相对简单，也不需要在商户平台进行设置什么的（我这里就没有进行什么设置，沿用的还是以前的设置，但是我看了文档很明显此种扫码支付方式没有用到以前的配置，文档中也没有提到要进行什么设置。仅供参考！！！！！！！！）
完成上述代码之后，写一个测试接口：

//微信支付接口
    @RequestMapping("/wxPay")
    public String wxPay(WeChatParams ps) throws Exception {
        ps.setBody("测试商品3");
        ps.setTotal_fee("1");
        ps.setOut_trade_no("hw5409550792199899");
        ps.setAttach("xiner");
        ps.setMemberid("888");
        String urlCode = WeixinPay.getCodeUrl(ps);
        System.out.println(urlCode);
        return "";

    }

直接在浏览器中访问此接口，控制台打印以下信息：

接收到以上返回信息后我们将code_url对应的链接地址转成二维码，然后用微信中的扫一扫，扫码生成的二维码进行支付。

我们点击立即支付，输入密码完成支付。

在我们完成支付的同时，微信会调用我们的回调接口。告诉我们支付结果，我们就可以根据这个支付结果进行业务处理，同时告知微信端我们收到了支付结果通知。
另附上用户支付完成是控制台打印的信息：