本文主要是介绍java实现公众号微信支付功能，走了很多弯路，决定把代码全部贴出来，警示萌新，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
公众号实现微信支付的前提条件
1、是认证的服务号，开通了微信支付功能
不能是订阅号，不能没有认证，不能没有开通微信支付功能
2、获取公众号的appid与秘钥
3、开通了微信商户平台，微信商户平台开通了JSAPI支付
4、把商户平台与这个服务号关联起来，在商户平台里面产品中心里面，有关联设置；然后再服务号里面同意就可以了
5、获取商户平台的商户号与秘钥！
无论是商户开发平台的私钥还是服务号的秘钥，要重设的，这个东西不会存储在平台里面！
微信支付的第一步、获取openid
看这个更具体 https://blog.csdn.net/tian_jiangnan/article/details/105724200
微信支付第二步、在商户开发平台设置支付目录
前提：你的域名备案了，域名解析了
设置支付目录的例子
我的域名是www.jianshu.com
我的javaweb项目,我的项目名称是gold
我设置的支付目录是www.jianshu.com/gold 记得保存
在微信公众号里面设置ip白名单，没错就是把你的服务器公网ip地址写上去，然后保存
现在就呈上我实现微信支付的整个流程吧！
设置公众号菜单，我添加了一个菜单在线支付
这个在线支付绑定的网页是www.jianshu.com/gold/index.jsp
在这个首页Index.jsp里面有一个在线支付的按钮，这个按钮的链接是
<a href="https://open.weixin.qq.com/connect/oauth2/authorize?
appid=wx99*************68&redirect_uri=http%3a%2f%2fwww.jianshu.com%2fgold%2fpay.jsp&response_type=code&
scope=snsapi_base#wechat_redirect"><button type="button" class="btn btn-info" style="margin-left:40%;">在线登记</button></a></div>注意redirect_uri路径要进行编码
当我们进入这个pay.jsp页面的时候，页面路径会自动添加上code参数信息
pay.jsp页面
<input type="text" code="${param.code}" id="code"
<button type="button" class="btn btn-default" onclick="pay()">微信支付</button>对于${param.code}不用感觉惊慌，不需要引入任何文件，就可以获取路径中的code参数
当我们点击微信支付按钮的时候，执行如下操作
pay方法是进行统一下单处理，而后面的onBridgeReady() 是执行支付成功以后的操作
function pay() {var recode = $("#code").attr("code");console.log("code信息:", recode);if (!recode) {//如果没有获取到code就中断return;}var url = "http://www.jianshu.com/gold/pay.do";$.ajax({url : url, //请求后台dataType : "json",data : {//money : 0.01,mycode : recode},success : function(result) {var log = eval(result);console.log("返回订单信息：", log);appId = log[0].appId;timeStamp = log[0].timeStamp;nonceStr = log[0].nonceStr;packages = log[0].package;signType = log[0].signType;paySign = log[0].paySign;if (typeof WeixinJSBridge == "undefined") {if (document.addEventListener) {document.addEventListener('WeixinJSBridgeReady', onBridgeReady,false);} else if (document.attachEvent) {document.attachEvent('WeixinJSBridgeReady',onBridgeReady);document.attachEvent('onWeixinJSBridgeReady',onBridgeReady);}} else {onBridgeReady();}},//success});//ajax},//pay//单独的方法function onBridgeReady() {WeixinJSBridge.invoke('getBrandWCPayRequest', {"appId" : appId, //公众号名称,由商户传入 "timeStamp" : timeStamp, //时间戳,自1970年以来的秒数 "nonceStr" : nonceStr, //随机串 "package" : packages,"signType" : signType, //微信签名方式： "paySign" : paySign//微信签名 }, function(res) {if (res.err_msg == "get_brand_wcpay_request:ok") {var url ="";var data={};var url = "http://www.jianshu.com/gold/insert.do";$.ajax({url : url, //请求后台dataType : "json",data :data,success : function(result) {console.log("返回订单信息：");},//success});//ajax//支付成功后跳转的页面} else if (res.err_msg == "get_brand_wcpay_request:cancel") {console.log('支付取消');} else if (res.err_msg == "get_brand_wcpay_request:fail") {console.log('支付失败');WeixinJSBridge.call('closeWindow');} //使用以上方式判断前端返回,微信团队郑重提示：res.err_msg将在用户支付成功后返回ok,但并不保证它绝对可靠。});}//单独的方法点击pay按钮，会跳转到后台 var url = "http://www.jianshu.com/gold/pay.do";
我们看看这个方法里面的代码吧
package cn.com.pay;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONArray;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.ServletActionContext;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import com.alibaba.fastjson.JSONObject;
import cn.com.sdk.WXPayUtil;
@Repository(value = "pay")
public class Pay {private static String APPID = "**********"; // 微信公众号idprivate static String SECRET = "**********"; // 微信公众号密钥idprivate static String MCHID = "**********"; // 微信支付商户号private static String KEY = "**********"; // 商户号对应的密钥private static String OPENIDURL = "https://api.weixin.qq.com/sns/oauth2/access_token?"; // 获取微信openid的链接private static String UNURL = "https://api.mch.weixin.qq.com/pay/unifiedorder"; // 微信统一下单链接private static String TRADETYPE = "JSAPI";// jsapi代表公众号支付private String mycode;private String money;@Autowiredprivate SessionFactory sessionfactory;public String getMycode() {return mycode;}public void setMycode(String mycode) {this.mycode = mycode;}public String getMoney() {return money;}public void setMoney(String money) {this.money = money;}private final Log log = LogFactory.getLog(getClass());//获取用户的openidpublic String getOpenid(){String getopenid_url = "https://api.weixin.qq.com/sns/oauth2/access_token";String param = "appid=" + APPID + "&secret=" + SECRET + "&code="+ mycode + "&grant_type=authorization_code";// 向微信服务器发送get请求获取openIdStrString openIdStr = HttpRequest.sendGet(getopenid_url, param);JSONObject json = JSONObject.parseObject(openIdStr);// 转成Json格式String openId = json.getString("openid");// 获取openIdlog.info("该用户的openid是 "+openId);return openId;}public String paymoney() {Map<String, String> paraMap = new HashMap<String, String>();log.info("mycode信息 "+mycode);int m=Integer.parseInt(money);money=Integer.toString(m*100);log.info("支付的金额是 "+money);openid=getOpenid();try { // 获取请求ip地址HttpServletRequest request = ServletActionContext.getRequest();String ip = request.getHeader("x-forwarded-for");if (ip == null || ip.length() == 0|| "unknown".equalsIgnoreCase(ip)) {ip = request.getHeader("Proxy-Client-IP");}if (ip == null || ip.length() == 0|| "unknown".equalsIgnoreCase(ip)) {ip = request.getHeader("WL-Proxy-Client-IP");}if (ip == null || ip.length() == 0|| "unknown".equalsIgnoreCase(ip)) {ip = request.getRemoteAddr();}if (ip.indexOf(",") != -1) {String[] ips = ip.split(",");ip = ips[0].trim();}paraMap.put("appid", APPID);paraMap.put("body", "online");//这里写中文会乱码，会导致签名不正确paraMap.put("mch_id", MCHID);paraMap.put("nonce_str", WXPayUtil.generateNonceStr());paraMap.put("openid", openid);// 随机生成一个订单号paraMap.put("out_trade_no", getOrderIdByTime());// 订单号System.out.println("订单号是");System.out.println(getOrderIdByTime());log.info("订单号是 "+getOrderIdByTime());paraMap.put("spbill_create_ip", ip);paraMap.put("total_fee", money);paraMap.put("trade_type", "JSAPI");// 此路径是微信服务器调用支付结果通知路径paraMap.put("notify_url", "http://www.jiancs.com/gold/backs.do");String sign = WXPayUtil.generateSignature(paraMap, KEY);log.info("签名如下： "+sign);paraMap.put("sign", sign);String xml = WXPayUtil.mapToXml(paraMap);// 将所有参数(map)转xml格式log.info("xml如下: "+xml);String unifiedorder_url = "https://api.mch.weixin.qq.com/pay/unifiedorder";String xmlStr = HttpRequest.sendPost(unifiedorder_url, xml);// 发送post请求"统一下单接口"返回预支付id:prepay_id// 以下内容是返回前端页面的json数据log.info("调了统一接口的xmlStr如下: "+xmlStr);String prepay_id = "";// 预支付idif (xmlStr.indexOf("SUCCESS") != -1) {Map<String, String> map = WXPayUtil.xmlToMap(xmlStr);prepay_id = (String) map.get("prepay_id");}log.info("此时获取到的prepay_id如下: "+prepay_id);Map<String, String> payMap = new HashMap<String, String>();payMap.put("appId", APPID);payMap.put("timeStamp", WXPayUtil.getCurrentTimestamp() + "");payMap.put("nonceStr", WXPayUtil.generateNonceStr());payMap.put("signType", "MD5");payMap.put("package", "prepay_id=" + prepay_id);log.info("prepay_id如下: "+"prepay_id=" + prepay_id);String paySign = WXPayUtil.generateSignature(payMap, KEY);log.info("paySign如下: "+paySign);payMap.put("paySign", paySign);payMap.put("openid", openid);// 把payMap给前台HttpServletResponse response = ServletActionContext.getResponse();response.setCharacterEncoding("utf-8");try {JSONArray re = JSONArray.fromObject(payMap);String result = re.toString();PrintWriter writer = response.getWriter();writer.write(result);// 返回json数组writer.flush();writer.close();} catch (IOException e) {e.printStackTrace();}return null;} catch (Exception e) {e.printStackTrace();}return null;}// 随机订单号public static String getOrderIdByTime() {SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");String newDate = sdf.format(new Date());String result = "";Random random = new Random();for (int i = 0; i < 3; i++) {result += random.nextInt(10);}return newDate + result;}
}
支付成功以后的回掉类与方法
package cn.com.pay;
import java.io.InputStream;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.ServletActionContext;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;import cn.com.bean.Order;
import cn.com.sdk.WXPayUtil;@Repository(value="wxPayController")
public class WxPayController {@Autowiredprivate Order o;@Autowiredprivate SessionFactory sessionfactory;private final Log log = LogFactory.getLog(getClass());@Transactionalpublic String callBack(){System.out.println("微信支付成功,微信发送的callback信息,请注意修改订单信息");log.info("微信支付成功,微信发送的callback信息,请注意修改订单信息"); HttpServletRequest request = ServletActionContext.getRequest();HttpServletResponse response = ServletActionContext.getResponse();InputStream is = null;try {is = request.getInputStream();//获取请求的流信息(这里是微信发的xml格式所有只能使用流来读)String xml = WXPayUtil.inputStream2String(is, "UTF-8");Map<String, String> notifyMap = WXPayUtil.xmlToMap(xml);//将微信发的xml转maplog.info("回调成功的代xml"+xml); if(notifyMap.get("return_code").equals("SUCCESS")){ if(notifyMap.get("result_code").equals("SUCCESS")){ String ordersSn = notifyMap.get("out_trade_no");//商户订单号 String amountpaid = notifyMap.get("total_fee");//实际支付的订单金额:单位 分BigDecimal amountPay = (new BigDecimal(amountpaid).divide(new BigDecimal("100"))).setScale(2);//将分转换成元-实际支付金额:元SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式String time=df.format(new Date());// new Date()为获取当前系统时间/*以下是自己的业务处理------仅做参考* 更新order对应字段/已支付金额/状态码*///获取当前时间o.setMoney(amountPay+"");o.setOut_trade_no(ordersSn);o.setDate(time);//存储到数据库里面Session session = sessionfactory.openSession();session.save(o);session.close();//存储到数据库里面 } }//告诉微信服务器收到信息了，不要在调用回调action了========这里很重要回复微信服务器信息用流发送一个xml即可response.getWriter().write("<xml><return_code><![CDATA[SUCCESS]]></return_code></xml>"); is.close();} catch (Exception e) {e.printStackTrace();}return null;}
}
其实实现微信支付的主要是一些公众号官方提供的类
HttpRequest.java
package cn.com.pay;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;public class HttpRequest {/*** 向指定URL发送GET方法的请求* * @param url* 发送请求的URL* @param param* 请求参数,请求参数应该是 name1=value1&name2=value2 的形式。* @return URL 所代表远程资源的响应结果*/public static String sendGet(String url, String param) {String result = "";BufferedReader in = null;try {String urlNameString = url + "?" + param;System.out.println(urlNameString);URL realUrl = new URL(urlNameString);// 打开和URL之间的连接URLConnection connection = realUrl.openConnection();// 设置通用的请求属性connection.setRequestProperty("accept", "*/*");connection.setRequestProperty("connection", "Keep-Alive");connection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");// 建立实际的连接connection.connect();// 获取所有响应头字段Map<String, List<String>> map = connection.getHeaderFields();// 遍历所有的响应头字段for (String key : map.keySet()) {System.out.println(key + "--->" + map.get(key));}// 定义 BufferedReader输入流来读取URL的响应in = new BufferedReader(new InputStreamReader(connection.getInputStream()));String line;while ((line = in.readLine()) != null) {result += line;}} catch (Exception e) {System.out.println("发送GET请求出现异常！" + e);e.printStackTrace();}// 使用finally块来关闭输入流finally {try {if (in != null) {in.close();}} c这篇关于java实现公众号微信支付功能，走了很多弯路，决定把代码全部贴出来，警示萌新的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
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