Java 后端微信支付demo

后端微信支付demo"/>

Java 后端微信支付demo

一、导入微信SDK

二、在微信商户平台下载证书放在项目的resources目录下的cert文件夹下（cert文件夹需要自己建）

三、实现微信的WXPayConfig接口

package com.ieou.demomon;import com.github.wxpay.sdk.WXPayConfig;
import org.apachemons.io.IOUtils;import java.io.ByteArrayInputStream;
import java.io.InputStream;/** 配置我们自己的信息  */public class OurWxPayConfig implements WXPayConfig {/** 加载证书  这里证书需要到微信商户平台进行下载*/private byte [] certData;public OurWxPayConfig() throws  Exception{InputStream certStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("cert/wxpay/apiclient_cert.p12");this.certData = IOUtils.toByteArray(certStream);certStream.close();}/** 设置我们自己的appid* 商户号* 秘钥* */@Overridepublic String getAppID() {return "wx7494893843843c";}@Overridepublic String getMchID() {return "4672984344";}@Overridepublic String getKey() {return "qbH5l4N3468798dfgK";}@Overridepublic InputStream getCertStream() {return new ByteArrayInputStream(this.certData);}@Overridepublic int getHttpConnectTimeoutMs() {return 0;}@Overridepublic int getHttpReadTimeoutMs() {return 0;}
}

四、构建自己的参数

package com.ieou.demomon;import java.math.BigDecimal;public class WxpayParam {/** 微信支付的金额是String类型 并且是以分为单位* 下面举个例子单位是元是怎么转为分的* */BigDecimal totalPrice  = new BigDecimal(1); //此时的单位是元private String body = "xxx等商品信息";private String totalFee = totalPrice.multiply(new BigDecimal(100)).toBigInteger().toString();/** 随机数字字符串*/private String outTradeNo = "4784984230432842944";public String getBody() {return body;}public void setBody(String body) {this.body = body;}public String getTotalFee() {return totalFee;}public void setTotalFee(String totalFee) {this.totalFee = totalFee;}public String getOutTradeNo() {return outTradeNo;}public void setOutTradeNo(String outTradeNo) {this.outTradeNo = outTradeNo;}
}

五、配置微信统一下单接口需要的参数，并调用微信统一下单接口

package com.ieou.demo.controller;import com.github.wxpay.sdk.WXPay;
import com.github.wxpay.sdk.WXPayUtil;
import com.ieou.demomon.OurWxPayConfig;
import com.ieou.demomon.WxpayParam;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.HashMap;
import java.util.Map;@RestController
@RequestMapping("/")
public class WxPayController {@GetMapping("/pay")public Map<String,String> wxPayFunction() throws Exception{WxpayParam wxpayParam = new WxpayParam();String notifyUrl = "www.baidu";  //我这里的回调地址是随便写的，到时候需要换成处理业务的回调接口OurWxPayConfig ourWxPayConfig = new OurWxPayConfig();WXPay wxPay = new WXPay(ourWxPayConfig);//根据微信支付api来设置Map<String,String> data = new HashMap<>();data.put("appid",ourWxPayConfig.getAppID());data.put("mch_id",ourWxPayConfig.getMchID());         //商户号data.put("trade_type","APP");                         //支付场景 APP 微信app支付 JSAPI 公众号支付  NATIVE 扫码支付data.put("notify_url",notifyUrl);                     //回调地址data.put("spbill_create_ip","127.0.0.1");             //终端ipdata.put("total_fee",wxpayParam.getTotalFee());       //订单总金额data.put("fee_type","CNY");                           //默认人民币data.put("out_trade_no",wxpayParam.getOutTradeNo());   //交易号data.put("body",wxpayParam.getBody());data.put("nonce_str","bfrhncjkfdkfd");   // 随机字符串小于32位String s = WXPayUtil.generateSignature(data, ourWxPayConfig.getKey());  //签名data.put("sign",s);/** wxPay.unifiedOrder 这个方法中调用微信统一下单接口 */Map<String, String> respData = wxPay.unifiedOrder(data); if (respData.get("return_code").equals("SUCCESS")){//返回给APP端的参数，APP端再调起支付接口Map<String,String> repData = new HashMap<>();repData.put("appid",ourWxPayConfig.getAppID());repData.put("mch_id",ourWxPayConfig.getMchID());repData.put("prepayid",respData.get("prepay_id"));repData.put("package","WXPay");repData.put("noncestr",respData.get("nonce_str"));repData.put("timestamp",String.valueOf(System.currentTimeMillis()/1000));String sign = WXPayUtil.generateSignature(repData,ourWxPayConfig.getKey()); //签名respData.put("sign",sign);respData.put("timestamp",repData.get("timestamp"));respData.put("package","WXPay");return respData;}throw new Exception(respData.get("return_msg"));}
}

六、至此，后端代码已经结束，前端拿到返回值调用微信发起支付接口就可以了。