✨ 集成“饿了么”授权登录（未测试）

README.en-US.md

@@ -67,6 +67,7 @@
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/kujiale.png" width="20"></td>
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/gitlab.png" width="20"></td>
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/meituan.png" width="20"></td>
+            <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/eleme.png" width="20"></td>
         </tr>
     </table>
 </center>
@@ -152,6 +153,7 @@ authRequest.login(callback);
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/kujiale.png" width="20">  |  [AuthKujialeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthKujialeRequest.java)  |  <a href="https://open.kujiale.com/open/apps/2/docs?doc_id=95" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/gitlab.png" width="20">  |  [AuthGitlabRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthGitlabRequest.java)  |  <a href="https://docs.gitlab.com/ee/api/oauth2.html" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/meituan.png" width="20">  |  [AuthMeituanRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthMeituanRequest.java)  |  <a href="http://open.waimai.meituan.com/openapi_docs/oauth/" target="_blank">参考文档</a> |
+|  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/eleme.png" width="20">  |  [AuthElemeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthElemeRequest.java)  |  <a href="https://open.shop.ele.me/openapi/documents/khd001" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/csdn.png" width="20">  |  [AuthCsdnRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthCsdnRequest.java)  |  无 |
 
 

README.md

@@ -67,6 +67,7 @@
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/kujiale.png" width="20"></td>
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/gitlab.png" width="20"></td>
             <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/meituan.png" width="20"></td>
+            <td align="center" width="200"><img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/eleme.png" width="20"></td>
         </tr>
     </table>
 </center>
@@ -162,6 +163,7 @@ authRequest.login(callback);
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/kujiale.png" width="20">  |  [AuthKujialeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthKujialeRequest.java)  |  <a href="https://open.kujiale.com/open/apps/2/docs?doc_id=95" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/gitlab.png" width="20">  |  [AuthGitlabRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthGitlabRequest.java)  |  <a href="https://docs.gitlab.com/ee/api/oauth2.html" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/meituan.png" width="20">  |  [AuthMeituanRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthMeituanRequest.java)  |  <a href="http://open.waimai.meituan.com/openapi_docs/oauth/" target="_blank">参考文档</a> |
+|  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/eleme.png" width="20">  |  [AuthElemeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthElemeRequest.java)  |  <a href="https://open.shop.ele.me/openapi/documents/khd001" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/csdn.png" width="20">  |  [AuthCsdnRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthCsdnRequest.java)  |  无 |
 
 _请知悉：经咨询CSDN官方客服得知，CSDN的授权开放平台已经下线。如果以前申请过的应用，可以继续使用，但是不再支持申请新的应用。so, 本项目中的CSDN登录只能针对少部分用户使用了_

docs/README.md

@@ -87,10 +87,11 @@ JustAuth，如你所见，它仅仅是一个**第三方授权登录**的**工具
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/stackoverflow.png" width="20">  | [AuthStackOverflowRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthStackOverflowRequest.java) | <a href="https://api.stackexchange.com/docs/authentication" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/huawei.png" width="20">  | [AuthHuaweiRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthHuaweiRequest.java) | <a href="https://developer.huawei.com/consumer/cn/devservice/doc/30101" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/wechat.png" width="20">  | [AuthWeChatEnterpriseRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthWeChatEnterpriseRequest.java) | <a href="https://open.work.weixin.qq.com/api/doc#90000/90135/90664" target="_blank">参考文档</a> |
-|  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/csdn.png" width="20">  |  [AuthCsdnRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthCsdnRequest.java)  |  无 |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/kujiale.png" width="20">  |  [AuthKujialeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthKujialeRequest.java)  |  <a href="https://open.kujiale.com/open/apps/2/docs?doc_id=95" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/gitlab.png" width="20">  |  [AuthGitlabRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthGitlabRequest.java)  |  <a href="https://docs.gitlab.com/ee/api/oauth2.html" target="_blank">参考文档</a> |
 |  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/meituan.png" width="20">  |  [AuthMeituanRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthMeituanRequest.java)  |  <a href="http://open.waimai.meituan.com/openapi_docs/oauth/" target="_blank">参考文档</a> |
+|  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/eleme.png" width="20">  |  [AuthElemeRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthElemeRequest.java)  |  <a href="https://open.shop.ele.me/openapi/documents/khd001" target="_blank">参考文档</a> |
+|  <img src="https://gitee.com/yadong.zhang/static/raw/master/JustAuth/csdn.png" width="20">  |  [AuthCsdnRequest](https://gitee.com/yadong.zhang/JustAuth/blob/master/src/main/java/me/zhyd/oauth/request/AuthCsdnRequest.java)  |  无 |
 
 
 ## 快速开始

docs/update.md

@@ -2,6 +2,7 @@
 ### 2019/09/06
 
 - 集成“美团”授权登录
+- 集成“饿了么”授权登录
 - 升级Fastjson依赖到1.2.60，预防[“Fastjson ＜ 1.2.60 远程拒绝服务漏洞预警”](https://card.weibo.com/article/m/show/id/2309404413257925394542)
 
 ## v1.11.0

src/main/java/me/zhyd/oauth/config/AuthSource.java

@@ -643,6 +643,35 @@ public enum AuthSource {
         public String refresh() {
             return "https://openapi.waimai.meituan.com/oauth/refresh_token";
         }
+    },
+
+    /**
+     * 饿了么
+     * <p>
+     * 注：集成的是正式环境，非沙箱环境
+     *
+     * @since 1.12.0
+     */
+    ELEME {
+        @Override
+        public String authorize() {
+            return "https://open-api.shop.ele.me/authorize";
+        }
+
+        @Override
+        public String accessToken() {
+            return "https://open-api.shop.ele.me/token";
+        }
+
+        @Override
+        public String userInfo() {
+            return "https://open-api.shop.ele.me/api/v1/";
+        }
+
+        @Override
+        public String refresh() {
+            return "https://open-api.shop.ele.me/token";
+        }
     };
 
     /**

src/main/java/me/zhyd/oauth/request/AuthElemeRequest.java

+package me.zhyd.oauth.request;
+
+import cn.hutool.core.codec.Base64;
+import cn.hutool.http.HttpRequest;
+import cn.hutool.http.HttpResponse;
+import com.alibaba.fastjson.JSONObject;
+import me.zhyd.oauth.cache.AuthStateCache;
+import me.zhyd.oauth.config.AuthConfig;
+import me.zhyd.oauth.config.AuthSource;
+import me.zhyd.oauth.enums.AuthResponseStatus;
+import me.zhyd.oauth.enums.AuthUserGender;
+import me.zhyd.oauth.exception.AuthException;
+import me.zhyd.oauth.model.AuthCallback;
+import me.zhyd.oauth.model.AuthResponse;
+import me.zhyd.oauth.model.AuthToken;
+import me.zhyd.oauth.model.AuthUser;
+import me.zhyd.oauth.utils.GlobalAuthUtil;
+import me.zhyd.oauth.utils.UrlBuilder;
+import me.zhyd.oauth.utils.UuidUtils;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 饿了么
+ * <p>
+ * 注：集成的是正式环境，非沙箱环境
+ *
+ * @author yadong.zhang (yadong.zhang0415(a)gmail.com)
+ * @since 1.12.0
+ */
+public class AuthElemeRequest extends AuthDefaultRequest {
+
+    public AuthElemeRequest(AuthConfig config) {
+        super(config, AuthSource.ELEME);
+    }
+
+    public AuthElemeRequest(AuthConfig config, AuthStateCache authStateCache) {
+        super(config, AuthSource.ELEME, authStateCache);
+    }
+
+    @Override
+    protected AuthToken getAccessToken(AuthCallback authCallback) {
+
+        HttpRequest request = HttpRequest.post(source.accessToken())
+            .form("client_id", config.getClientId())
+            .form("redirect_uri", config.getRedirectUri())
+            .form("code", authCallback.getCode())
+            .form("grant_type", "authorization_code");
+
+        // 设置header
+        this.setHeader(request);
+
+        HttpResponse response = request.execute();
+        JSONObject object = JSONObject.parseObject(response.body());
+
+        this.checkResponse(object);
+
+        return AuthToken.builder()
+            .openId(this.getOpenId(authCallback.getCode()))
+            .accessToken(object.getString("access_token"))
+            .refreshToken(object.getString("refresh_token"))
+            .tokenType(object.getString("token_type"))
+            .expireIn(object.getIntValue("expires_in"))
+            .build();
+    }
+
+    @Override
+    protected AuthUser getUserInfo(AuthToken authToken) {
+        Map<String, Object> parameters = new HashMap<>();
+        // 获取商户账号信息的API接口名称
+        String action = "eleme.user.getUser";
+        // 时间戳，单位秒。API服务端允许客户端请求最大时间误差为正负5分钟。
+        final long timestamp = System.currentTimeMillis();
+        // 公共参数
+        Map<String, Object> metasHashMap = new HashMap<String, Object>();
+        metasHashMap.put("app_key", config.getClientId());
+        metasHashMap.put("timestamp", timestamp);
+        String signature = GlobalAuthUtil.generateElemeSignature(config.getClientId(), config.getClientSecret(), timestamp, action, authToken.getAccessToken(), parameters);
+
+        HttpRequest request = HttpRequest.post(source.userInfo())
+            .form("nop", "1.0.0")
+            .form("id", this.getRequestId())
+            .form("metas", metasHashMap)
+            .form("action", action)
+            .form("token", authToken.getAccessToken())
+            .form("params", parameters)
+            .form("signature", signature);
+
+        // 设置header
+        this.setHeader(request, "application/json; charset=utf-8");
+
+        HttpResponse response = request.execute();
+
+        JSONObject object = JSONObject.parseObject(response.body());
+
+        // 校验请求
+        if (object.containsKey("error")) {
+            throw new AuthException(object.getJSONObject("error").getString("message"));
+        }
+
+        JSONObject result = object.getJSONObject("result");
+
+        return AuthUser.builder()
+            .uuid(result.getString("userId"))
+            .username(result.getString("userName"))
+            .nickname(result.getString("userName"))
+            .gender(AuthUserGender.UNKNOWN)
+            .token(authToken)
+            .source(source)
+            .build();
+    }
+
+    @Override
+    public AuthResponse refresh(AuthToken oldToken) {
+        HttpRequest request = HttpRequest.post(source.refresh())
+            .form("refresh_token", oldToken.getRefreshToken())
+            .form("grant_type", "refresh_token");
+
+        // 设置header
+        this.setHeader(request);
+
+        HttpResponse response = request.execute();
+        JSONObject object = JSONObject.parseObject(response.body());
+
+        this.checkResponse(object);
+
+        return AuthResponse.builder()
+            .code(AuthResponseStatus.SUCCESS.getCode())
+            .data(AuthToken.builder()
+                .accessToken(object.getString("access_token"))
+                .refreshToken(object.getString("refresh_token"))
+                .tokenType(object.getString("token_type"))
+                .expireIn(object.getIntValue("expires_in"))
+                .build())
+            .build();
+    }
+
+    @Override
+    public String authorize(String state) {
+        return UrlBuilder.fromBaseUrl(super.authorize(state))
+            .queryParam("scope", "all")
+            .build();
+    }
+
+    private String getOpenId(String code) {
+        HttpRequest request = HttpRequest.post("https://open-api.shop.ele.me/identity")
+            .form("grant_type", "authorization_code")
+            .form("code", code)
+            .form("redirect_uri", config.getRedirectUri())
+            .form("client_id", config.getClientId());
+
+        // 设置header
+        this.setHeader(request);
+
+        HttpResponse response = request.execute();
+        JSONObject object = JSONObject.parseObject(response.body());
+
+        this.checkResponse(object);
+        return object.getString("openId");
+    }
+
+    private String getBasic(String appKey, String appSecret) {
+        StringBuilder sb = new StringBuilder();
+        String encodeToString = Base64.encode((appKey + ":" + appSecret).getBytes());
+        sb.append("Basic").append(" ").append(encodeToString);
+        return sb.toString();
+    }
+
+    private void setHeader(HttpRequest request) {
+        setHeader(request, "application/x-www-form-urlencoded;charset=UTF-8");
+    }
+
+    private void setHeader(HttpRequest request, String contentType) {
+        request.header("Accept", "text/xml,text/javascript,text/html")
+            .header("Content-Type", contentType)
+            .header("Accept-Encoding", "gzip")
+            .header("User-Agent", "eleme-openapi-java-sdk")
+            .header("x-eleme-requestid", getRequestId())
+            .header("Authorization", this.getBasic(config.getClientId(), config.getClientSecret()));
+    }
+
+    private String getRequestId() {
+        return UuidUtils.getUUID() + "|" + System.currentTimeMillis();
+    }
+
+    private void checkResponse(JSONObject object) {
+        if (object.containsKey("error")) {
+            throw new AuthException(object.getString("error_description"));
+        }
+    }
+
+}

src/main/java/me/zhyd/oauth/request/AuthMeituanRequest.java

@@ -74,11 +74,11 @@ public class AuthMeituanRequest extends AuthDefaultRequest {
 
     @Override
     public AuthResponse refresh(AuthToken oldToken) {
-        HttpResponse response = HttpRequest.post(source.accessToken())
+        HttpResponse response = HttpRequest.post(source.refresh())
             .form("app_id", config.getClientId())
             .form("secret", config.getClientSecret())
             .form("refresh_token", oldToken.getRefreshToken())
-            .form("grant_type", "authorization_code")
+            .form("grant_type", "refresh_token")
             .execute();
         JSONObject object = JSONObject.parseObject(response.body());
 

src/main/java/me/zhyd/oauth/utils/GlobalAuthUtil.java

@@ -4,6 +4,7 @@ import cn.hutool.core.codec.Base64;
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.util.ObjectUtil;
 import cn.hutool.http.HttpUtil;
+import com.alibaba.fastjson.JSON;
 import me.zhyd.oauth.exception.AuthException;
 
 import javax.crypto.Mac;
@@ -14,6 +15,7 @@ import java.net.URLEncoder;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.security.InvalidKeyException;
+import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.*;
 
@@ -27,11 +29,25 @@ public class GlobalAuthUtil {
     private static final Charset DEFAULT_ENCODING = StandardCharsets.UTF_8;
     private static final String ALGORITHM = "HmacSHA256";
 
+    /**
+     * 生成钉钉请求的Signature
+     *
+     * @param secretKey 平台应用的授权密钥
+     * @param timestamp 时间戳
+     * @return Signature
+     */
     public static String generateDingTalkSignature(String secretKey, String timestamp) {
         byte[] signData = sign(secretKey.getBytes(DEFAULT_ENCODING), timestamp.getBytes(DEFAULT_ENCODING));
         return urlEncode(new String(Base64.encode(signData, false)));
     }
 
+    /**
+     * 签名
+     *
+     * @param key  key
+     * @param data data
+     * @return byte[]
+     */
     private static byte[] sign(byte[] key, byte[] data) {
         try {
             Mac mac = Mac.getInstance(ALGORITHM);
@@ -44,11 +60,16 @@ public class GlobalAuthUtil {
         }
     }
 
+    /**
+     * 编码
+     *
+     * @param value str
+     * @return encode str
+     */
     public static String urlEncode(String value) {
         if (value == null) {
             return "";
         }
-
         try {
             String encoded = URLEncoder.encode(value, GlobalAuthUtil.DEFAULT_ENCODING.displayName());
             return encoded.replace("+", "%20").replace("*", "%2A").replace("~", "%7E").replace("/", "%2F");
@@ -57,6 +78,13 @@ public class GlobalAuthUtil {
         }
     }
 
+
+    /**
+     * 解码
+     *
+     * @param value str
+     * @return decode str
+     */
     public static String urlDecode(String value) {
         if (value == null) {
             return "";
@@ -68,6 +96,12 @@ public class GlobalAuthUtil {
         }
     }
 
+    /**
+     * string字符串转map，str格式为 {@code xxx=xxx&xxx=xxx}
+     *
+     * @param accessTokenStr 待转换的字符串
+     * @return map
+     */
     public static Map<String, String> parseStringToMap(String accessTokenStr) {
         Map<String, String> res = new HashMap<>();
         if (accessTokenStr.contains("&")) {
@@ -82,7 +116,13 @@ public class GlobalAuthUtil {
         return res;
     }
 
-
+    /**
+     * map转字符串，转换后的字符串格式为 {@code xxx=xxx&xxx=xxx}
+     *
+     * @param params 待转换的map
+     * @param encode 是否转码
+     * @return str
+     */
     public static String parseMapToString(Map<String, Object> params, boolean encode) {
         List<String> paramList = new ArrayList<>();
         params.forEach((k, v) -> {
@@ -95,13 +135,25 @@ public class GlobalAuthUtil {
         });
         return CollUtil.join(paramList, "&");
     }
-  
+
+    /**
+     * 将url的参数列表转换成map
+     *
+     * @param url 待转换的url
+     * @return map
+     */
     public static Map<String, Object> parseQueryToMap(String url) {
         Map<String, Object> paramMap = new HashMap<>();
         HttpUtil.decodeParamMap(url, "UTF-8").forEach(paramMap::put);
         return paramMap;
     }
 
+    /**
+     * 是否为http协议
+     *
+     * @param url 待验证的url
+     * @return true: http协议, false: 非http协议
+     */
     public static boolean isHttpProtocol(String url) {
         if (StringUtils.isEmpty(url)) {
             return false;
@@ -109,6 +161,12 @@ public class GlobalAuthUtil {
         return url.startsWith("http://");
     }
 
+    /**
+     * 是否为https协议
+     *
+     * @param url 待验证的url
+     * @return true: https协议, false: 非https协议
+     */
     public static boolean isHttpsProtocol(String url) {
         if (StringUtils.isEmpty(url)) {
             return false;
@@ -116,8 +174,68 @@ public class GlobalAuthUtil {
         return url.startsWith("https://");
     }
 
+    /**
+     * 是否为本地主机（域名）
+     *
+     * @param url 待验证的url
+     * @return true: 本地主机（域名）, false: 非本地主机（域名）
+     */
     public static boolean isLocalHost(String url) {
         return StringUtils.isEmpty(url) || url.contains("127.0.0.1") || url.contains("localhost");
     }
 
+    /**
+     * 生成饿了么请求的Signature
+     * <p>
+     * 代码copy并修改自：https://coding.net/u/napos_openapi/p/eleme-openapi-java-sdk/git/blob/master/src/main/java/eleme/openapi/sdk/utils/SignatureUtil.java
+     *
+     * @param appKey     平台应用的授权key
+     * @param secret     平台应用的授权密钥
+     * @param timestamp  时间戳，单位秒。API服务端允许客户端请求最大时间误差为正负5分钟。
+     * @param action     饿了么请求的api方法
+     * @param token      用户授权的token
+     * @param parameters 加密参数
+     * @return Signature
+     */
+    public static String generateElemeSignature(String appKey, String secret, long timestamp, String action, String token, Map<String, Object> parameters) {
+        final Map<String, Object> sorted = new TreeMap<>();
+        for (Map.Entry<String, Object> entry : parameters.entrySet()) {
+            sorted.put(entry.getKey(), entry.getValue());
+        }
+        sorted.put("app_key", appKey);
+        sorted.put("timestamp", timestamp);
+        StringBuffer string = new StringBuffer();
+        for (Map.Entry<String, Object> entry : sorted.entrySet()) {
+            string.append(entry.getKey()).append("=").append(JSON.toJSONString(entry.getValue()));
+        }
+        String splice = String.format("%s%s%s%s", action, token, string, secret);
+        String calculatedSignature = md5(splice);
+        return calculatedSignature.toUpperCase();
+    }
+
+    /**
+     * MD5加密饿了么请求的Signature
+     * <p>
+     * 代码copy并修改自：https://coding.net/u/napos_openapi/p/eleme-openapi-java-sdk/git/blob/master/src/main/java/eleme/openapi/sdk/utils/SignatureUtil.java
+     *
+     * @param str 饿了么请求的Signature
+     * @return md5 str
+     */
+    private static String md5(String str) {
+        MessageDigest md = null;
+        StringBuilder buffer = null;
+        try {
+            md = MessageDigest.getInstance("MD5");
+            md.update(str.getBytes(StandardCharsets.UTF_8));
+            byte[] byteData = md.digest();
+            buffer = new StringBuilder();
+            for (byte byteDatum : byteData) {
+                buffer.append(Integer.toString((byteDatum & 0xff) + 0x100, 16).substring(1));
+            }
+        } catch (Exception ignored) {
+        }
+
+        return null == buffer ? "" : buffer.toString();
+    }
+
 }