Java调用微信支付功能的方法示例代码

<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.2.1.RELEASE</version>
 </parent>
 <dependencies>
  <!--spring boot -->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <!--微信提供的sdk-->
  <dependency>
   <groupId>com.github.wxpay</groupId>
   <artifactId>wxpay-sdk</artifactId>
   <version>0.0.3</version>
  </dependency>
  <!--发送http请求-->
  <dependency>
   <groupId>org.apache.httpcomponents</groupId>
   <artifactId>httpclient</artifactId>
  </dependency>
  <!--模板引擎-->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-freemarker</artifactId>
  </dependency>
 </dependencies>

# 服务端口
server.port=8081
# 微信开放平台 appid
wx.pay.app_id=
#商户号
wx.pay.partner=
#商户key
wx.pay.partnerkey=
#回调地址
wx.pay.notifyurl:

spring.freemarker.tempalte-loader-path=classpath:/templates
#  关闭缓存，及时刷新，上线生产环境需要修改为true
spring.freemarker.cache=false
spring.freemarker.charset=UTF-8
spring.freemarker.check-template-location=true
spring.freemarker.content-type=text/html
spring.freemarker.expose-request-attributes=true
spring.freemarker.expose-session-attributes=true
spring.freemarker.request-context-attribute=request
spring.freemarker.suffix=.ftl
spring.mvc.static-path-pattern: /static/**

@SpringBootApplication
@ComponentScan(basePackages = {"com.haiyang.wxpay"})
public class Application {

 public static void main(String[] args) {
  SpringApplication.run(Application.class, args);
 }
}

@Component
public class WxPayUtils implements InitializingBean {

 @Value("${wx.pay.app_id}")
 private String appId;

 @Value("${wx.pay.partner}")
 private String partner;

 @Value("${wx.pay.partnerkey}")
 private String partnerKey;
 @Value("${wx.pay.notifyurl}")
 private String notifyUrl;


 public static String WX_PAY_APP_ID;
 public static String WX_PAY_PARTNER;
 public static String WX_PAY_PARTNER_KEY;
 public static String WX_OPEN_NOTIFY_URL;

 @Override
 public void afterPropertiesSet() throws Exception {
  WX_PAY_APP_ID = appId;
  WX_PAY_PARTNER = partner;
  WX_PAY_PARTNER_KEY = partnerKey;
  WX_OPEN_NOTIFY_URL = notifyUrl;
 }

}

/**
 * http请求客户端
 * 
 * @author qy
 * 
 */
public class HttpClient {
	private String url;
	private Map<String, String> param;
	private int statusCode;
	private String content;
	private String xmlParam;
	private boolean isHttps;

	public boolean isHttps() {
		return isHttps;
	}

	public void setHttps(boolean isHttps) {
		this.isHttps = isHttps;
	}

	public String getXmlParam() {
		return xmlParam;
	}

	public void setXmlParam(String xmlParam) {
		this.xmlParam = xmlParam;
	}

	public HttpClient(String url, Map<String, String> param) {
		this.url = url;
		this.param = param;
	}

	public HttpClient(String url) {
		this.url = url;
	}

	public void setParameter(Map<String, String> map) {
		param = map;
	}

	public void addParameter(String key, String value) {
		if (param == null)
			param = new HashMap<String, String>();
		param.put(key, value);
	}

	public void post() throws ClientProtocolException, IOException {
		HttpPost http = new HttpPost(url);
		setEntity(http);
		execute(http);
	}

	public void put() throws ClientProtocolException, IOException {
		HttpPut http = new HttpPut(url);
		setEntity(http);
		execute(http);
	}

	public void get() throws ClientProtocolException, IOException {
		if (param != null) {
			StringBuilder url = new StringBuilder(this.url);
			boolean isFirst = true;
			for (String key : param.keySet()) {
				if (isFirst)
					url.append("?");
				else
					url.append("&");
				url.append(key).append("=").append(param.get(key));
			}
			this.url = url.toString();
		}
		HttpGet http = new HttpGet(url);
		execute(http);
	}

	/**
	 * set http post,put param
	 */
	private void setEntity(HttpEntityEnclosingRequestBase http) {
		if (param != null) {
			List<NameValuePair> nvps = new LinkedList<NameValuePair>();
			for (String key : param.keySet())
				nvps.add(new BasicNameValuePair(key, param.get(key))); // 参数
			http.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8)); // 设置参数
		}
		if (xmlParam != null) {
			http.setEntity(new StringEntity(xmlParam, Consts.UTF_8));
		}
	}

	private void execute(HttpUriRequest http) throws ClientProtocolException,
			IOException {
		CloseableHttpClient httpClient = null;
		try {
			if (isHttps) {
				SSLContext sslContext = new SSLContextBuilder()
						.loadTrustMaterial(null, new TrustStrategy() {
							// 信任所有
							public boolean isTrusted(X509Certificate[] chain,
									String authType)
									throws CertificateException {
								return true;
							}
						}).build();
				SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
						sslContext);
				httpClient = HttpClients.custom().setSSLSocketFactory(sslsf)
						.build();
			} else {
				httpClient = HttpClients.createDefault();
			}
			CloseableHttpResponse response = httpClient.execute(http);
			try {
				if (response != null) {
					if (response.getStatusLine() != null)
						statusCode = response.getStatusLine().getStatusCode();
					HttpEntity entity = response.getEntity();
					// 响应内容
					content = EntityUtils.toString(entity, Consts.UTF_8);
				}
			} finally {
				response.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			httpClient.close();
		}
	}

	public int getStatusCode() {
		return statusCode;
	}

	public String getContent() throws ParseException, IOException {
		return content;
	}

}

@Controller
@RequestMapping("/wxpay")
public class WxPayController {
 @RequestMapping("/pay")
 public String createPayQRcode(Model model) throws Exception{

  String price = "0.01";
  String no = getOrderNo();
  Map m = new HashMap();
  m.put("appid", WxPayUtils.WX_PAY_APP_ID);
  m.put("mch_id", WxPayUtils.WX_PAY_PARTNER);
  m.put("nonce_str", WXPayUtil.generateNonceStr());
  m.put("body","微信支付测试"); //主体信息
  m.put("out_trade_no", no); //订单唯一标识
  m.put("total_fee", getMoney(price));//金额
  m.put("spbill_create_ip", "127.0.0.1");//项目的域名
  m.put("notify_url", WxPayUtils.WX_OPEN_NOTIFY_URL);//回调地址
  m.put("trade_type", "NATIVE");//生成二维码的类型

  //3 发送httpclient请求，传递参数xml格式，微信支付提供的固定的地址
  HttpClient client = new HttpClient("https://api.mch.weixin.qq.com/pay/unifiedorder");
  //设置xml格式的参数
  //把xml格式的数据加密
  client.setXmlParam(WXPayUtil.generateSignedXml(m, WxPayUtils.WX_PAY_PARTNER_KEY));
  client.setHttps(true);
  //执行post请求发送
  client.post();
  //4 得到发送请求返回结果
  //返回内容，是使用xml格式返回
  String xml = client.getContent();
  //把xml格式转换map集合，把map集合返回
  Map<String,String> resultMap = WXPayUtil.xmlToMap(xml);
  //最终返回数据 的封装
  Map map = new HashMap();
  map.put("no", no);
  map.put("price", price);
  map.put("result_code", resultMap.get("result_code"));
  map.put("code_url", resultMap.get("code_url"));

  model.addAttribute("map",map);
  return "pay";

 }

 @GetMapping("queryorder/{no}")
 @ResponseBody
 public String queryPayStatus(@PathVariable String no) throws Exception{
  //1、封装参数
  Map m = new HashMap<>();
  m.put("appid", WxPayUtils.WX_PAY_APP_ID);
  m.put("mch_id", WxPayUtils.WX_PAY_PARTNER);
  m.put("out_trade_no", no);
  m.put("nonce_str", WXPayUtil.generateNonceStr());

  //2 发送httpclient
  HttpClient client = new HttpClient("https://api.mch.weixin.qq.com/pay/orderquery");
  client.setXmlParam(WXPayUtil.generateSignedXml(m, WxPayUtils.WX_PAY_PARTNER_KEY));
  client.setHttps(true);
  client.post();

  //3.得到订单数据
  String xml = client.getContent();
  Map<String, String> resultMap = WXPayUtil.xmlToMap(xml);

  //4.判断是否支付成功
  if(resultMap.get("trade_state").equals("SUCCESS")) {
   /*
     改变数据库中的数据等操作
    */
   return "支付成功";
  }
  return "支付中";
 }

 @GetMapping("success")
 public String success(){
  return "success";
 }
 @RequestMapping("test")
 public String test(){
  return "pay";
 }
 /**
  * 生成订单号
  * @return
  */
 public static String getOrderNo() {
  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;
 }
 /**
  * 元转换成分
  * @param amount
  * @return
  */
 public static String getMoney(String amount) {
  if(amount==null){
   return "";
  }
  // 金额转化为分为单位
  // 处理包含, ￥ 或者$的金额
  String currency = amount.replaceAll("\\$|\\￥|\\,", "");
  int index = currency.indexOf(".");
  int length = currency.length();
  Long amLong = 0l;
  if(index == -1){
   amLong = Long.valueOf(currency+"00");
  }else if(length - index >= 3){
   amLong = Long.valueOf((currency.substring(0, index+3)).replace(".", ""));
  }else if(length - index == 2){
   amLong = Long.valueOf((currency.substring(0, index+2)).replace(".", "")+0);
  }else{
   amLong = Long.valueOf((currency.substring(0, index+1)).replace(".", "")+"00");
  }
  return amLong.toString();
 }
}

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>Title</title>
 <script src="/static/qrcode.js"></script>
 <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>
</head>
<center>
 <div id="qrcode"></div>
</center>
<script type="text/javascript">
 new QRCode(document.getElementById("qrcode"), "${map.code_url}"); // 设置要生成二维码的链接
</script>
<script type="text/javascript">
 var int=self.setInterval("querystatus()",3000);
 function querystatus() {
  $.get("/wxpay/queryorder/${map.no}",function(data,status){
   if (data==="支付中"){
    console.log("支付中");
   } else {
    clearInterval(int)
    window.location.href="/wxpay/success" rel="external nofollow" 
   }
  })
 }
</script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>Title</title>
</head>
<body>
<h1>支付成功</h1>
</body>
</html>