Java微信支付回调通知

        <!-- WeChat Pay -->
        <dependency>
            <groupId>com.github.wechatpay-apiv3</groupId>
            <artifactId>wechatpay-apache-httpclient</artifactId>
            <version>0.2.0</version>
        </dependency>
        <dependency>
            <groupId>com.github.wxpay</groupId>
            <artifactId>wxpay-sdk</artifactId>
            <version>0.0.3</version>
        </dependency>

    /**
     * 微信支付回调通知
     * @param request
     * @param response
     * @return
     * @throws Exception
     */
    @PostMapping("wXCallBack")
    public String wXCallBack(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ServletInputStream inputStream = null;
        inputStream = request.getInputStream();
        String notifyXml = StreamUtil.inputStreamString(inputStream, "utf-8");
        //验签
        if (WXPayUtil.isSignatureValid(notifyXml, "your key")) {
            log.info("[支付_微信支付]验签成功！");
            //解析返回结果
            JSONObject jsonObject = WeChatPayUtil.xmlToJson(notifyXml);
            String result_code = jsonObject.getString("result_code");
            //判断是否支付成功
            if (result_code.equals(WXPayConstants.SUCCESS)) {
                /**todo 处理业务 省略，根据自己业务补充 **/

                //支付成功，回传通知微信已收到交易成功通知
                HashMap<String, String> map = new HashMap<>();
                map.put("return_code", "SUCCESS");
                map.put("return_msg", "OK");
                String resultXml = WXPayUtil.mapToXml(map);
                response.setContentType("text/xml");
                log.info("[支付_微信支付]通知已处理");
                return resultXml;
            }
        }
        //微信收到校验失败的结果后，会以一定时间间隔持续调用该返回结果
        Map<String, String> returnMap = new HashMap<>();
        returnMap.put("return_code", "FAIL");
        returnMap.put("return_msg", "");
        String returnXml = WXPayUtil.mapToXml(returnMap);
        log.info("[支付_微信支付]处理失败！");
        response.setContentType("text/xml");
        return returnXml;
    }

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Created with IDEA
 * Author: www.itze.cn
 * Date: 2021-07-07
 * Email：gitlab@111.com
 */
public class StreamUtil {

    private static int _buffer_size = 1024;

    /**
     * InputStream流转换成String字符串
     *
     * @param inStream InputStream流
     * @param encoding 编码格式
     * @return String字符串
     */
    public static String inputStreamString(InputStream inStream, String encoding) {
        String result = null;
        ByteArrayOutputStream outStream = null;
        try {
            if (inStream != null) {
                outStream = new ByteArrayOutputStream();
                byte[] tempBytes = new byte[_buffer_size];
                int count = -1;
                while ((count = inStream.read(tempBytes, 0, _buffer_size)) != -1) {
                    outStream.write(tempBytes, 0, count);
                }
                outStream.flush();
                result = new String(outStream.toByteArray(), encoding);
                outStream.close();
            }
        } catch (Exception e) {
            result = null;
        } finally {
            try {
                if (inStream != null) inStream.close();
                if (outStream != null) outStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }
}

        <!-- 解析xml -->
        <dependency>
            <groupId>org.dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>2.1.1</version>
        </dependency>

    /**
     * 解析字符串形式的XML内容
     *
     * @param xmlContent
     * @return
     * @throws DocumentException
     */
    public static JSONObject xmlToJson(String xmlContent) throws DocumentException {
        Document document = DocumentHelper.parseText(xmlContent);
        Element rootElement = document.getRootElement();
        Iterator iterator = rootElement.elementIterator();
        JSONObject jsonObject = new JSONObject();
        while (iterator.hasNext()) {
            DefaultElement defaultElement = (DefaultElement) iterator.next();
            jsonObject.fluentPut(defaultElement.getName(), defaultElement.getStringValue());
        }
        return jsonObject;
    }