Java实现微信小程序支付(准备)

Java语言开发微信小程序支付功能：

1.通过https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=11_1路径到官方下载Java的支付SDK。

2.下载后将pom文件中需要用到的jar包导入自己的项目中，将demo全部导入到自己的工具包中，需导入的demo如下图：

3.此时缺少IWXPayDomain与WXPayConfig抽象类的具体实现，新建WXPayDomainSimpleImpl与WXPayConfigImpl来分别实现抽象类，代码如下：

WXPayDomainSimpleImpl代码：

 package com.karat.cn.util;
 import org.apache.http.conn.ConnectTimeoutException;

 import java.net.UnknownHostException;
 import java.util.HashMap;
 import java.util.Map;

 /**
  * Created by blaketang on 2017/6/16.
  */
 public class WXPayDomainSimpleImpl implements IWXPayDomain {
     private WXPayDomainSimpleImpl(){}
     private static class WxpayDomainHolder{
         private static IWXPayDomain holder = new WXPayDomainSimpleImpl();
     }
     public static IWXPayDomain instance(){
         return WxpayDomainHolder.holder;
     }

     public synchronized void report(final String domain, long elapsedTimeMillis, final Exception ex) {
         DomainStatics info = domainData.get(domain);
         if(info == null){
             info = new DomainStatics(domain);
             domainData.put(domain, info);
         }

         if(ex == null){ //success
             if(info.succCount >= 2){    //continue succ, clear error count
                 info.connectTimeoutCount = info.dnsErrorCount = info.otherErrorCount = 0;
             }else{
                 ++info.succCount;
             }
         }else if(ex instanceof ConnectTimeoutException){
             info.succCount = info.dnsErrorCount = 0;
             ++info.connectTimeoutCount;
         }else if(ex instanceof UnknownHostException){
             info.succCount = 0;
             ++info.dnsErrorCount;
         }else{
             info.succCount = 0;
             ++info.otherErrorCount;
         }
     }

     public synchronized DomainInfo getDomain(final WXPayConfig config) {
         DomainStatics primaryDomain = domainData.get(WXPayConstants.DOMAIN_API);
         if(primaryDomain == null ||
                 primaryDomain.isGood()) {
             return new DomainInfo(WXPayConstants.DOMAIN_API, true);
         }

         long now = System.currentTimeMillis();
         if(switchToAlternateDomainTime == 0){   //first switch
             switchToAlternateDomainTime = now;
             return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
         }else if(now - switchToAlternateDomainTime < MIN_SWITCH_PRIMARY_MSEC){
             DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
             if(alternateDomain == null ||
                 alternateDomain.isGood() ||
                 alternateDomain.badCount() < primaryDomain.badCount()){
                 return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
             }else{
                 return new DomainInfo(WXPayConstants.DOMAIN_API, true);
             }
         }else{  //force switch back
             switchToAlternateDomainTime = 0;
             primaryDomain.resetCount();
             DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
             if(alternateDomain != null)
                 alternateDomain.resetCount();
             return new DomainInfo(WXPayConstants.DOMAIN_API, true);
         }
     }

     static class DomainStatics {
         final String domain;
         int succCount = 0;
         int connectTimeoutCount = 0;
         int dnsErrorCount =0;
         int otherErrorCount = 0;

         DomainStatics(String domain) {
             this.domain = domain;
         }
         void resetCount(){
             succCount = connectTimeoutCount = dnsErrorCount = otherErrorCount = 0;
         }
         boolean isGood(){ return connectTimeoutCount <= 2 && dnsErrorCount <= 2; }
         int badCount(){
             return connectTimeoutCount + dnsErrorCount * 5 + otherErrorCount / 4;
         }
     }
     private final int MIN_SWITCH_PRIMARY_MSEC = 3 * 60 * 1000;  //3 minutes
     private long switchToAlternateDomainTime = 0;
     private Map<String, DomainStatics> domainData = new HashMap<String, DomainStatics>();
 }

WXPayConfigImpl代码：

 package com.karat.cn.util;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;

 public class WXPayConfigImpl extends WXPayConfig{

     /**==========================================================================**/
     private byte[] certData;
     private static WXPayConfigImpl INSTANCE;

     private WXPayConfigImpl() throws Exception{
         String certPath = WXPayConfigImpl.class.getClassLoader().getResource("").getPath();
         File file = new File(certPath + "apiclient_cert.p12");
         InputStream certStream = new FileInputStream(file);
         this.certData = new byte[(int) file.length()];
         certStream.read(this.certData);
         certStream.close();
     }

     public static WXPayConfigImpl getInstance() throws Exception{
         if (INSTANCE == null) {
             synchronized (WXPayConfigImpl.class) {
                 if (INSTANCE == null) {
                     INSTANCE = new WXPayConfigImpl();
                 }
             }
         }
         return INSTANCE;
     }

     /**==========================================================================**/
     @Override
     public String getAppID() {
         // TODO Auto-generated method stub
         return "小程序AppId";
     }

     @Override
     public String getMchID() {
         // TODO Auto-generated method stub
         return "商户号";
     }

     @Override
     public String getKey() {
         // TODO Auto-generated method stub
         return "商户密钥";
     }

     @Override
     public InputStream getCertStream() {
         // TODO Auto-generated method stub
         ByteArrayInputStream certBis;
         certBis = new ByteArrayInputStream(this.certData);
         return certBis;
     }

     @Override
     public IWXPayDomain getWXPayDomain() {
         // TODO Auto-generated method stub
         return WXPayDomainSimpleImpl.instance();
     }

 }

4.向WXPayConstants.java中添加常量：

 public static final String TRANSFERS_URL_SUFFIX = "/mmpaymkttransfers/promotion/transfers";
 public static final String SANDBOX_SENDREDPACK_URL_SUFFIX = "/sandboxnew/mmpaymkttransfers/sendredpack";
 public static final String SANDBOX_TRANSFERS_URL_SUFFIX = "/sandboxnew/mmpaymkttransfers/promotion/transfers";

5.向WXPay.java中添加如下代码：

 /********************************************/
     // 企业付款
     public String transfers(Map<String, String> reqData) throws Exception {
         return this.transfers(reqData, config.getHttpConnectTimeoutMs(), this.config.getHttpReadTimeoutMs());
     }
     public String transfers(Map<String, String> reqData,  int connectTimeoutMs, int readTimeoutMs) throws Exception {
         String url;
         if (this.useSandbox) {
             url = WXPayConstants.SANDBOX_TRANSFERS_URL_SUFFIX;
         }
         else {
             url = WXPayConstants.TRANSFERS_URL_SUFFIX;
         }
         return this.requestWithCert(url, this.transfersRequestData(reqData), connectTimeoutMs, readTimeoutMs);
     }
     // 企业付款
     public Map<String, String> transfersRequestData(Map<String, String> reqData) throws Exception {
         // 商户号绑定的appid(小程序的appid)
         reqData.put("mch_appid", config.getAppID());
         // 商户号
         reqData.put("mchid", config.getMchID());
         // 随机字符串
         reqData.put("nonce_str", WXPayUtil.generateUUID());
         reqData.put("sign", WXPayUtil.generateSignature(reqData, config.getKey(), this.signType));
         return reqData;
     }

     /********************************************/

6.创建订单表以及返回给小程序端的参数vo

 package com.karat.cn.wxCommon;

 import java.util.Map;

 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.index.Indexed;
 import org.springframework.data.mongodb.core.mapping.Document;

 /**
  * 订单表
  * @author 开发
  *
  */
 @Document(collection = "wxWithdrawOrder")
 public class WxWithdrawOrder {
     /**
      * id
      */
     @Id
     private String id;
     /**
      * 会员id
      */
     @Indexed
     private String memberId;
     /**
      * 订单号
      */
     @Indexed(unique = true)
     private String orderNo;
     /**
      * 提现金额(分)
      */
     private int money;
     /**
      * 提现时间
      */
     private String createDate;
     /**
      * 订单状态(0:申请失败或异常 1:已申请成功)
      */
     private String orderStatus;
     /**
      * 扩展
      */
     private Map<String, String> remark;
     /**
      * 扩展2
      */
     private String remark2;

     public String getId() {
         return id;
     }
     public void setId(String id) {
         this.id = id;
     }
     public String getMemberId() {
         return memberId;
     }
     public void setMemberId(String memberId) {
         this.memberId = memberId;
     }
     public String getOrderNo() {
         return orderNo;
     }
     public void setOrderNo(String orderNo) {
         this.orderNo = orderNo;
     }
     public int getMoney() {
         return money;
     }
     public void setMoney(int money) {
         this.money = money;
     }
     public String getCreateDate() {
         return createDate;
     }
     public void setCreateDate(String createDate) {
         this.createDate = createDate;
     }
     public Map<String, String> getRemark() {
         return remark;
     }
     public void setRemark(Map<String, String> remark) {
         this.remark = remark;
     }
     public String getRemark2() {
         return remark2;
     }
     public void setRemark2(String remark2) {
         this.remark2 = remark2;
     }
     public String getOrderStatus() {
         return orderStatus;
     }
     public void setOrderStatus(String orderStatus) {
         this.orderStatus = orderStatus;
     }
 }

 package com.karat.cn.vo;
 /**
  *  调用微信支付相关信息
  * @author 开发
  *
  */
 public class VoUnifiedOrderWx {
     // 时间戳
     private String timeStamp;
     // 随机串
     private String nonceStr;
     // 数据包
     private String packageValue;
     // 签名
     private String sign;

     public String getTimeStamp() {
         return timeStamp;
     }
     public void setTimeStamp(String timeStamp) {
         this.timeStamp = timeStamp;
     }
     public String getNonceStr() {
         return nonceStr;
     }
     public void setNonceStr(String nonceStr) {
         this.nonceStr = nonceStr;
     }
     public String getPackageValue() {
         return packageValue;
     }
     public void setPackageValue(String packageValue) {
         this.packageValue = packageValue;
     }
     public String getSign() {
         return sign;
     }
     public void setSign(String sign) {
         this.sign = sign;
     }

 }

7.创建工具类(获取系统时间)

 package com.karat.cn.wxCommon;

 import java.text.ParseException;
 import java.util.Date;

 public class BaseToolsUtil {
     /**
      * 获取系统时间long
      *
      * @return
      * @throws ParseException
      */
     public static long systemtimeLong() {
         return new Date().getTime();
     }
 }

8.准备工作完毕，开始实现小程序支付，退款，提现功能。