前言

最近实现社群对接企业微信，对接的过程遇到一些点，在此记录。

企业微信介绍

企业微信具有和微信一样的体验，用于企业内部成员和外部客户的管理，可以由此构建出社群生态。
企业微信提供了丰富的api进行调用获取数据管理，也提供了各种回调事件，当数据发生变化时，可以及时知道。
我们分为两部分进行讲解，第一部分调用企业微信api，第二部分，接收企业微信的回调。

调用企业微信api

api的开发文档地址：https://work.weixin.qq.com/api/doc/90000/90135/90664
调用企业微信所必须的东西就是企业的accesstoken。获取accesstoken则需要我们的corpid和corpsercret。
具体我们可以参照这里https://work.weixin.qq.com/api/doc/90000/90135/91039
有了token之后，我们就可以通过http请求来调用各种api，获取数据。举一个例子，创建成员的api，如下，我们只要使用http工具调用即可。

这里分享一个http调用工具。

@Slf4j
public class HttpUtils { static CloseableHttpClient httpClient;

    private HttpUtils() { throw new IllegalStateException("Utility class");
    }

    static {
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();
        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(registry);
        connectionManager.setMaxTotal(200);
        connectionManager.setDefaultMaxPerRoute(200);
        connectionManager.setDefaultSocketConfig(
                SocketConfig.custom().setSoTimeout(15, TimeUnit.SECONDS)
                        .setTcpNoDelay(true).build()
        );
        connectionManager.setValidateAfterInactivity(TimeValue.ofSeconds(15));

        httpClient = HttpClients.custom()
                .setConnectionManager(connectionManager)
                .disableAutomaticRetries()
                .build();
    }

    public static String get(String url, Map<String, Object> paramMap, Map<String, String> headerMap) {
        String param = paramMap.entrySet().stream().map(n -> n.getKey() + "=" + n.getValue()).collect(Collectors.joining("&"));
        String fullUrl = url + "?" + param;
        final HttpGet httpGet = new HttpGet(fullUrl); if (Objects.nonNull(headerMap) && headerMap.size() > 0) {
            headerMap.forEach((key, value) -> httpGet.addHeader(key, value));
        } CloseableHttpResponse response = null; try { response = httpClient.execute(httpGet); String strResult = EntityUtils.toString(response.getEntity()); if (200 != response.getCode()) { log.error("HTTP get 返回状态非200[resp={}]", strResult);
            } return strResult;
        } catch (IOException | ParseException e) { log.error("HTTP get 异常", e); return "";
        } finally { if (null != response) { try { EntityUtils.consume(response.getEntity());
                } catch (IOException e) { e.printStackTrace();
                }
            }
        }
    } public static String post(String url,Map<String, Object> paramMap, Map<String, String> headerMap, String data) { CloseableHttpResponse response = null; try { String param = paramMap.entrySet().stream().map(n -> n.getKey() + "=" + n.getValue()).collect(Collectors.joining("&")); String fullUrl = url + "?" + param; final HttpPost httpPost = new HttpPost(fullUrl); if (Objects.nonNull(headerMap) && headerMap.size() > 0) { headerMap.forEach((key, value) -> httpPost.addHeader(key, value));
            } StringEntity httpEntity = new StringEntity(data, StandardCharsets.UTF_8); httpPost.setEntity(httpEntity); response = httpClient.execute(httpPost); if (200 == response.getCode()) { String strResult = EntityUtils.toString(response.getEntity()); return strResult;
            }
        } catch (IOException | ParseException e) { e.printStackTrace(); return "";
        } finally { if (null != response) { try { EntityUtils.consume(response.getEntity());
                } catch (IOException e) { e.printStackTrace();
                }
            }
        } return "";
    }
}

对接企业微信的回调

回调分为很多种，比如通讯录的回调如下：
https://work.weixin.qq.com/api/doc/90000/90135/90967

整体的回调流程如下：
配置回调服务，需要有三个配置项，分别是：URL, Token, EncodingAESKey。
首先，URL为回调服务地址，由开发者搭建，用于接收通知消息或者事件。

其次，Token用于计算签名，由英文或数字组成且长度不超过32位的自定义字符串。开发者提供的URL是公开可访问的，这就意味着拿到这个URL，就可以往该链接推送消息。那么URL服务需要解决两个问题：

如何分辨出是否为企业微信来源
如何分辨出推送消息的内容是否被篡改
通过数字签名就可以解决上述的问题。具体为：约定Token作为密钥，仅开发者和企业微信知道，在传输中不可见，用于参与签名计算。企业微信在推送消息时，将消息内容与Token计算出签名。开发者接收到推送消息时，也按相同算法计算出签名。如果为同一签名，则可信任来源为企业微信，并且内容是完整的。

如果非企业微信来源，由于攻击者没有正确的Token，无法算出正确的签名；
如果消息内容被篡改，由于开发者会将接收的消息内容与Token重算一次签名，该值与参数的签名不一致，则会拒绝该请求。

最后，EncodingAESKey用于消息内容加密，由英文或数字组成且长度为43位的自定义字符串。由于消息是在公开的因特网上传输，消息内容是可被截获的，如果内容未加密，则截获者可以直接阅读消息内容。若消息内容包含一些敏感信息，就非常危险了。EncodingAESKey就是在这个背景基础上提出，将发送的内容进行加密，并组装成一定格式后再发送。

对接回调，我们就要实现上述的加密，篡改等代码。这里分享java版本的实现。
AesException

public class AesException extends Exception { public final static int OK = 0; public final static int ValidateSignatureError = -40001; public final static int ParseXmlError = -40002; public final static int ComputeSignatureError = -40003; public final static int IllegalAesKey = -40004; public final static int ValidateCorpidError = -40005; public final static int EncryptAESError = -40006; public final static int DecryptAESError = -40007; public final static int IllegalBuffer = -40008; private int code; private static String getMessage(int code) { switch (code) { case ValidateSignatureError: return "签名验证错误"; case ParseXmlError: return "xml解析失败"; case ComputeSignatureError: return "sha加密生成签名失败"; case IllegalAesKey: return "SymmetricKey非法"; case ValidateCorpidError: return "corpid校验失败"; case EncryptAESError: return "aes加密失败"; case DecryptAESError: return "aes解密失败"; case IllegalBuffer: return "解密后得到的buffer非法";  default: return null;
        }
    } public int getCode() { return code;
    }

    AesException(int code) { super(getMessage(code)); this.code = code;
    }

}

MessageUtil

public class MessageUtil { /**  * 解析微信发来的请求（XML）.  * * @param msg 消息  * @return map  */ public static Map<String, String> parseXml(final String msg) { // 将解析结果存储在HashMap中 Map<String, String> map = new HashMap<String, String>(); // 从request中取得输入流 try (InputStream inputStream = new ByteArrayInputStream(msg.getBytes(StandardCharsets.UTF_8.name()))) { // 读取输入流 SAXReader reader = new SAXReader();
            Document document = reader.read(inputStream); // 得到xml根元素 Element root = document.getRootElement(); // 得到根元素的所有子节点 List<Element> elementList = root.elements(); // 遍历所有子节点 for (Element e : elementList) {
                map.put(e.getName(), e.getText());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } return map;
    }

}

public enum QywechatEnum {

    TEST("测试", "123123123123", "123123123123", "12312312312"); /**
     * 应用名
     */ private String name; /**
     * 企业ID
     */ private String corpid; /**
     * 回调url配置的token
     */ private String token; /**
     * 随机加密串
     */ private String encodingAESKey;


    QywechatEnum(final String name, final String corpid, final String token, final String encodingAESKey) { this.name = name; this.corpid = corpid; this.encodingAESKey = encodingAESKey; this.token = token;
    } public String getCorpid() { return corpid;
    } public String getName() { return name;
    } public String getToken() { return token;
    } public String getEncodingAESKey() { return encodingAESKey;
    }

}

public class QywechatInfo { /**
     * 签名
     */ private String msgSignature; /**
     * 随机时间戳
     */ private String timestamp; /**
     * 随机值
     */ private String nonce; /**
     * 加密的xml字符串
     */ private String sPostData; /**
     * 企业微信回调配置
     */ private QywechatEnum qywechatEnum;

}

public class SHA1Utils { /**
     * 用SHA1算法生成安全签名
     *
     * @param token     票据
     * @param timestamp 时间戳
     * @param nonce     随机字符串
     * @param encrypt   密文
     * @return 安全签名
     * @throws AesException
     */ public static String getSHA1(String token, String timestamp, String nonce, String encrypt) throws AesException { try {
            String[] array = new String[]{token, timestamp, nonce, encrypt};
            StringBuffer sb = new StringBuffer(); // 字符串排序 Arrays.sort(array);
            for (int i = 0; i < 4; i++) {
                sb.append(array[i]);
            }
            String str = sb.toString(); // SHA1签名生成 MessageDigest md = MessageDigest.getInstance("SHA-1");
            md.update(str.getBytes());
            byte[] digest = md.digest();
            StringBuffer hexstr = new StringBuffer();
            String shaHex = "";
            for (int i = 0; i < digest.length; i++) {
                shaHex = Integer.toHexString(digest[i] & 0xFF); if (shaHex.length() < 2) {
                    hexstr.append(0);
                }
                hexstr.append(shaHex);
            }
            return hexstr.toString();
        } catch (Exception e) {
            e.printStackTrace();
            throw new AesException(AesException.ComputeSignatureError);
        }
    }

}

public class WXBizMsgCrypt { static Charset CHARSET = Charset.forName("utf-8");
    Base64 base64 = new Base64(); byte[] aesKey; String token; String receiveid; /**
     * 构造函数
     *
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */ public WXBizMsgCrypt(final QywechatEnum qywechatEnum) throws AesException { this.token = qywechatEnum.getToken(); this.receiveid = qywechatEnum.getCorpid(); String encodingAesKey = qywechatEnum.getEncodingAESKey(); if (encodingAesKey.length() != 43) { throw new AesException(AesException.IllegalAesKey);
        }
        aesKey = Base64.decodeBase64(encodingAesKey + "=");

    } // 生成4个字节的网络字节序 byte[] getNetworkBytesOrder(int sourceNumber) { byte[] orderBytes = new byte[4];
        orderBytes[3] = (byte) (sourceNumber & 0xFF);
        orderBytes[2] = (byte) (sourceNumber >> 8 & 0xFF);
        orderBytes[1] = (byte) (sourceNumber >> 16 & 0xFF);
        orderBytes[0] = (byte) (sourceNumber >> 24 & 0xFF); return orderBytes;
    } // 还原4个字节的网络字节序 int recoverNetworkBytesOrder(byte[] orderBytes) { int sourceNumber = 0; for (int i = 0; i < 4; i++) {
            sourceNumber <<= 8;
            sourceNumber |= orderBytes[i] & 0xff;
        } return sourceNumber;
    } // 随机生成16位字符串 String getRandomStr() { String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuffer sb = new StringBuffer(); for (int i = 0; i < 16; i++) { int number = random.nextInt(base.length());
            sb.append(base.charAt(number));
        } return sb.toString();
    } /**
     * 对明文进行加密.
     *
     * @param text 需要加密的明文
     * @return 加密后base64编码的字符串
     * @throws AesException aes加密失败
     */ String encrypt(String randomStr, String text) throws AesException {
        ByteGroup byteCollector = new ByteGroup(); byte[] randomStrBytes = randomStr.getBytes(CHARSET); byte[] textBytes = text.getBytes(CHARSET); byte[] networkBytesOrder = getNetworkBytesOrder(textBytes.length); byte[] receiveidBytes = receiveid.getBytes(CHARSET); // randomStr + networkBytesOrder + text + receiveid byteCollector.addBytes(randomStrBytes);
        byteCollector.addBytes(networkBytesOrder);
        byteCollector.addBytes(textBytes);
        byteCollector.addBytes(receiveidBytes); // ... + pad: 使用自定义的填充方式对明文进行补位填充 byte[] padBytes = PKCS7Encoder.encode(byteCollector.size());
        byteCollector.addBytes(padBytes); // 获得最终的字节流, 未加密 byte[] unencrypted = byteCollector.toBytes(); try { // 设置加密模式为AES的CBC模式 Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec keySpec = new SecretKeySpec(aesKey, "AES");
            IvParameterSpec iv = new IvParameterSpec(aesKey, 0, 16);
            cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv); // 加密 byte[] encrypted = cipher.doFinal(unencrypted); // 使用BASE64对加密后的字符串进行编码 String base64Encrypted = base64.encodeToString(encrypted); return base64Encrypted;
        } catch (Exception e) {
            e.printStackTrace(); throw new AesException(AesException.EncryptAESError);
        }
    } /**
     * 对密文进行解密.
     *
     * @param text 需要解密的密文
     * @return 解密得到的明文
     * @throws AesException aes解密失败
     */ String decrypt(String text) throws AesException { byte[] original; try { // 设置解密模式为AES的CBC模式 Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec key_spec = new SecretKeySpec(aesKey, "AES");
            IvParameterSpec iv = new IvParameterSpec(Arrays.copyOfRange(aesKey, 0, 16));
            cipher.init(Cipher.DECRYPT_MODE, key_spec, iv); // 使用BASE64对密文进行解码 byte[] encrypted = Base64.decodeBase64(text); // 解密 original = cipher.doFinal(encrypted);
        } catch (Exception e) {
            e.printStackTrace(); throw new AesException(AesException.DecryptAESError);
        } String xmlContent, from_receiveid; try { // 去除补位字符 byte[] bytes = PKCS7Encoder.decode(original); // 分离16位随机字符串,网络字节序和receiveid byte[] networkOrder = Arrays.copyOfRange(bytes, 16, 20); int xmlLength = recoverNetworkBytesOrder(networkOrder);

            xmlContent = new String(Arrays.copyOfRange(bytes, 20, 20 + xmlLength), CHARSET);
            from_receiveid = new String(Arrays.copyOfRange(bytes, 20 + xmlLength, bytes.length),
                    CHARSET);
        } catch (Exception e) {
            e.printStackTrace(); throw new AesException(AesException.IllegalBuffer);
        } // receiveid不相同的情况 if (!from_receiveid.equals(receiveid)) { throw new AesException(AesException.ValidateCorpidError);
        } return xmlContent;

    } /**
     * 将企业微信回复用户的消息加密打包.
     * <ol>
     *     <li>对要发送的消息进行AES-CBC加密</li>
     *     <li>生成安全签名</li>
     *     <li>将消息密文和安全签名打包成xml格式</li>
     * </ol>
     *
     * @param replyMsg 企业微信待回复用户的消息，xml格式的字符串
     * @param timeStamp 时间戳，可以自己生成，也可以用URL参数的timestamp
     * @param nonce 随机串，可以自己生成，也可以用URL参数的nonce
     *
     * @return 加密后的可以直接回复用户的密文，包括msg_signature, timestamp, nonce, encrypt的xml格式的字符串
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */ public String EncryptMsg(String replyMsg, String timeStamp, String nonce) throws AesException { // 加密 String encrypt = encrypt(getRandomStr(), replyMsg); // 生成安全签名 if (timeStamp == "") {
            timeStamp = Long.toString(System.currentTimeMillis());
        } String signature = SHA1Utils.getSHA1(token, timeStamp, nonce, encrypt); // System.out.println("发送给平台的签名是: " + signature[1].toString()); // 生成发送的xml String result = XMLParse.generate(encrypt, signature, timeStamp, nonce); return result;
    } /**
     * 检验消息的真实性，并且获取解密后的明文.
     * <ol>
     *     <li>利用收到的密文生成安全签名，进行签名验证</li>
     *     <li>若验证通过，则提取xml中的加密消息</li>
     *     <li>对消息进行解密</li>
     * </ol>
     *
     * @param qywechatInfo  bean
     * @return 解密后的原文
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */ public String decryptMsg(final QywechatInfo qywechatInfo) throws AesException { // 密钥，公众账号的app secret // 提取密文 Object[] encrypt = XMLParse.extract(qywechatInfo.getSPostData()); /**
         * @param msgSignature 签名串，对应URL参数的msg_signature
         * @param timeStamp 时间戳，对应URL参数的timestamp
         * @param nonce 随机串，对应URL参数的nonce
         * @param postData 密文，对应POST请求的数据
         */ // 验证安全签名 String signature = SHA1Utils.getSHA1(token, qywechatInfo.getTimestamp(), qywechatInfo.getNonce(), encrypt[1].toString()); // 和URL中的签名比较是否相等 // System.out.println("第三方收到URL中的签名：" + msg_sign); // System.out.println("第三方校验签名：" + signature); if (!signature.equals(qywechatInfo.getMsgSignature())) { throw new AesException(AesException.ValidateSignatureError);
        } // 解密 String result = decrypt(encrypt[1].toString()); return result;
    } /**
     * 验证URL
     * @param msgSignature 签名串，对应URL参数的msg_signature
     * @param timeStamp 时间戳，对应URL参数的timestamp
     * @param nonce 随机串，对应URL参数的nonce
     * @param echoStr 随机串，对应URL参数的echostr
     *
     * @return 解密之后的echostr
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */ public String verifyURL(String msgSignature, String timeStamp, String nonce, String echoStr) throws AesException { String signature = SHA1Utils.getSHA1(token, timeStamp, nonce, echoStr); if (!signature.equals(msgSignature)) { throw new AesException(AesException.ValidateSignatureError);
        } String result = decrypt(echoStr); return result;
    } static class ByteGroup { ArrayList<Byte> byteContainer = new ArrayList<Byte>(); public byte[] toBytes() { byte[] bytes = new byte[byteContainer.size()]; for (int i = 0; i < byteContainer.size(); i++) {
                bytes[i] = byteContainer.get(i);
            } return bytes;
        } public ByteGroup addBytes(byte[] bytes) { for (byte b : bytes) {
                byteContainer.add(b);
            } return this;
        } public int size() { return byteContainer.size();
        }
    } static class PKCS7Encoder { static Charset CHARSET = Charset.forName("utf-8"); static int BLOCK_SIZE = 32; /**
         * 获得对明文进行补位填充的字节.
         *
         * @param count 需要进行填充补位操作的明文字节个数
         * @return 补齐用的字节数组
         */ static byte[] encode(int count) { // 计算需要填充的位数 int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE); if (amountToPad == 0) {
                amountToPad = BLOCK_SIZE;
            } // 获得补位所用的字符 char padChr = chr(amountToPad); String tmp = new String(); for (int index = 0; index < amountToPad; index++) {
                tmp += padChr;
            } return tmp.getBytes(CHARSET);
        } /**
         * 删除解密后明文的补位字符
         *
         * @param decrypted 解密后的明文
         * @return 删除补位字符后的明文
         */ static byte[] decode(byte[] decrypted) { int pad = (int) decrypted[decrypted.length - 1]; if (pad < 1 || pad > 32) {
                pad = 0;
            } return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
        } /**
         * 将数字转化成ASCII码对应的字符，用于对明文进行补码
         *
         * @param a 需要转化的数字
         * @return 转化得到的字符
         */ static char chr(int a) { byte target = (byte) (a & 0xFF); return (char) target;
        }

    }

}

public class XMLParse { /**  * 提取出xml数据包中的加密消息  * * @param xmltext 待提取的xml字符串  * @return 提取出的加密消息字符串  * @throws AesException  */ public static Object[] extract(String xmltext) throws AesException { Object[] result = new Object[3]; try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); String FEATURE = null; // This is the PRIMARY defense. If DTDs (doctypes) are disallowed, almost all XML entity attacks are prevented // Xerces 2 only - http://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl FEATURE = "http://apache.org/xml/features/disallow-doctype-decl";
            dbf.setFeature(FEATURE, true); // If you can't completely disable DTDs, then at least do the following: // Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-general-entities // Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-general-entities // JDK7+ - http://xml.org/sax/features/external-general-entities FEATURE = "http://xml.org/sax/features/external-general-entities";
            dbf.setFeature(FEATURE, false); // Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-parameter-entities // Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-parameter-entities // JDK7+ - http://xml.org/sax/features/external-parameter-entities FEATURE = "http://xml.org/sax/features/external-parameter-entities";
            dbf.setFeature(FEATURE, false); // Disable external DTDs as well FEATURE = "http://apache.org/xml/features/nonvalidating/load-external-dtd";
            dbf.setFeature(FEATURE, false); // and these as well, per Timothy Morgan's 2014 paper: "XML Schema, DTD, and Entity Attacks" dbf.setXIncludeAware(false);
            dbf.setExpandEntityReferences(false); // And, per Timothy Morgan: "If for some reason support for inline DOCTYPEs are a requirement, then // ensure the entity settings are disabled (as shown above) and beware that SSRF attacks // (http://cwe.mitre.org/data/definitions/918.html) and denial // of service attacks (such as billion laughs or decompression bombs via "jar:") are a risk." // remaining parser logic DocumentBuilder db = dbf.newDocumentBuilder();
            StringReader sr = new StringReader(xmltext);
            InputSource is = new InputSource(sr);
            Document document = db.parse(is); Element root = document.getDocumentElement();
            NodeList nodelist1 = root.getElementsByTagName("Encrypt");
            NodeList nodelist2 = root.getElementsByTagName("ToUserName");
            result[0] = 0;
            result[1] = nodelist1.item(0).getTextContent();
            result[2] = nodelist2.item(0).getTextContent(); return result;
        } catch (Exception e) {
            e.printStackTrace(); throw new AesException(AesException.ParseXmlError);
        }
    } /**  * 生成xml消息  * * @param encrypt   加密后的消息密文  * @param signature 安全签名  * @param timestamp 时间戳  * @param nonce     随机字符串  * @return 生成的xml字符串  */ public static String generate(String encrypt, String signature, String timestamp, String nonce) { String format = "<xml>\n" + "<Encrypt><![CDATA[%1$s]]></Encrypt>\n" + "<MsgSignature><![CDATA[%2$s]]></MsgSignature>\n" + "<TimeStamp>%3$s</TimeStamp>\n" + "<Nonce><![CDATA[%4$s]]></Nonce>\n" + "</xml>"; return String.format(format, encrypt, signature, timestamp, nonce);

    }
}

public class CallbackController { @Resource private CallbackProducer callbackProducer; /**
     * get请求用于验签
     */ @GetMapping(value = "/callback") public void receiveMsg(@RequestParam(name = "msg_signature") final String msgSignature,
                           @RequestParam(name = "timestamp") final String timestamp,
                           @RequestParam(name = "nonce") final String nonce,
                           @RequestParam(name = "echostr") final String echostr, final HttpServletResponse response) throws Exception {
        QywechatEnum qywechatEnum = QywechatEnum.JXPP; log.info("get验签请求参数 msg_signature {}, timestamp {}, nonce {} , echostr {}", msgSignature, timestamp, nonce, echostr);
        WXBizMsgCrypt wxBizMsgCrypt = new WXBizMsgCrypt(qywechatEnum); String sEchoStr = wxBizMsgCrypt.verifyURL(msgSignature, timestamp, nonce, echostr);
        PrintWriter out = response.getWriter(); try { //必须要返回解密之后的明文 if (StringUtils.isBlank(sEchoStr)) { log.info("get验签URL验证失败");
            } else { log.info("get验签验证成功!");
            }
        } catch (Exception e) { log.error("get验签报错！", e);
        } log.info("get验签的echo是{}", sEchoStr);
        out.write(sEchoStr);
        out.flush();
    } /**
     * 企业微信客户联系回调
     */ @ResponseBody
    @PostMapping(value = "/callback") public String acceptMessage(final HttpServletRequest request,
                                @RequestParam(name = "msg_signature") final String sMsgSignature,
                                @RequestParam(name = "timestamp") final String sTimestamp,
                                @RequestParam(name = "nonce") final String sNonce) {
        QywechatEnum qywechatEnum = QywechatEnum.TEST; try {
            InputStream inputStream = request.getInputStream(); String sPostData = IOUtils.toString(inputStream, "UTF-8");
            QywechatInfo qywechatInfo = new QywechatInfo();
            qywechatInfo.setMsgSignature(sMsgSignature);
            qywechatInfo.setNonce(sNonce);
            qywechatInfo.setQywechatEnum(qywechatEnum);
            qywechatInfo.setTimestamp(sTimestamp);
            qywechatInfo.setSPostData(sPostData);
            WXBizMsgCrypt msgCrypt = new WXBizMsgCrypt(qywechatInfo.getQywechatEnum()); String sMsg = msgCrypt.decryptMsg(qywechatInfo);
            Map<String, String> dataMap = MessageUtil.parseXml(sMsg); log.info("回调的xml数据转为map的数据{}", JsonHelper.toJSONString(dataMap));
        } catch (Exception e) { log.info("回调报错", e);
        } return "success";
    }


}

如上代码拷贝好后，我们便可以在企业微信的回调事件配置界面，增加回调的连接地址。

实现方案过程中遇到的点

1、回调配置的地址只支持一个，所以要把回调服务抽取出来，申请公网域名。要注意将接收到的回调消息放到消息队列，供其他所有服务接收处理。
2、处理回调要注意逆序问题，假如更新操作先来了，新增操作还没有开始。
3、可以采用消息补偿，定时任务刷新机制，手动同步机制，保证数据的一致性。
4、要实现重试机制，因为可能触发微信的并发调用限制。