diff --git a/ddal-datasource/src/main/java/org/hellojavaer/ddal/datasource/DefaultDDALDataSource.java b/ddal-datasource/src/main/java/org/hellojavaer/ddal/datasource/DefaultDDALDataSource.java
index 88db627..29c8cb4 100644
--- a/ddal-datasource/src/main/java/org/hellojavaer/ddal/datasource/DefaultDDALDataSource.java
+++ b/ddal-datasource/src/main/java/org/hellojavaer/ddal/datasource/DefaultDDALDataSource.java
@@ -64,7 +64,7 @@ public DefaultDDALDataSource(String url) {
      * jdbc:ddal:thin:
      * 
      */
-    public DefaultDDALDataSource(String url, String username, String password) {
+    public DefaultDDALDataSource(String url, String user, String password) {
         if (url != null) {
             url = url.trim();
         }
@@ -82,10 +82,9 @@ public DefaultDDALDataSource(String url, String username, String password) {
                 context = new ClassPathXmlApplicationContext(url2);
             } else if (url2.startsWith("file:")) {
                 context = new FileSystemXmlApplicationContext(url2);
-            } else if (url2.startsWith("//")) {
-                url2 = "http:" + url2;
+            } else if (url2.startsWith("http:") || url2.startsWith("https:")) {
                 Map<String, String> param = new LinkedHashMap<>();
-                param.put("username", username);
+                param.put("user", user);
                 param.put("password", password);
                 String content = HttpUtils.sendPost(url2, param);
                 Resource resource = new ByteArrayResource(content.getBytes());
diff --git a/ddal-example/pom.xml b/ddal-example/pom.xml
index b4be2c9..d793145 100644
--- a/ddal-example/pom.xml
+++ b/ddal-example/pom.xml
@@ -19,7 +19,6 @@
 
     <properties>
         <maven.test.skip>true</maven.test.skip>
-        <ddal.version>1.0.0-SNAPSHOT</ddal.version>
         <spring.version>4.2.6.RELEASE</spring.version>
         <jdk.version>1.7</jdk.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -98,7 +97,7 @@
             <dependency>
                 <groupId>org.hellojavaer.ddal</groupId>
                 <artifactId>ddal-bom</artifactId>
-                <version>${ddal.version}</version>
+                <version>${project.version}</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
diff --git a/ddal-sequence/src/main/java/org/hellojavaer/ddal/sequence/HttpSequenceRangeGetter.java b/ddal-sequence/src/main/java/org/hellojavaer/ddal/sequence/HttpSequenceRangeGetter.java
index c0d193c..e4043d3 100644
--- a/ddal-sequence/src/main/java/org/hellojavaer/ddal/sequence/HttpSequenceRangeGetter.java
+++ b/ddal-sequence/src/main/java/org/hellojavaer/ddal/sequence/HttpSequenceRangeGetter.java
@@ -22,6 +22,7 @@
 import java.net.URL;
 import java.net.URLDecoder;
 import java.net.URLEncoder;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -45,90 +46,111 @@ public HttpSequenceRangeGetter(String authorizeUrl, String clientId, String auth
     }
 
     /**
-     * param: client_id=1&access_token=12
-     * return: begin_value=1&end_value=2
+     * param: clientId= &accessToken= &schemaName= &tableName= &step=
+     * return: beginValue= &endValue= &errorCode= &errorMessage=
      */
     @Override
     public SequenceRange get(String schemaName, String tableName, int step) throws Exception {
         Map<String, String> param = new HashMap<>();
-        param.put("client_id", clientId);
-        param.put("access_token", accessToken);
-        param.put("schema_name", schemaName);
-        param.put("table_name", tableName);
+        param.put("clientId", clientId);
+        param.put("accessToken", accessToken);
+        param.put("schemaName", schemaName);
+        param.put("tableName", tableName);
         param.put("step", String.valueOf(step));
         String result = HttpUtils.sendPost(accessUrl, param);
-        String[] kvs = result.split("&");
-        Long beginValue = null;
-        Long endValue = null;
-        boolean hasErrorCode = false;
-        for (String item : kvs) {
-            String[] kv = item.split("=");
-            if ("error_code".equals(kv[0])) {
-                hasErrorCode = true;
-                break;
-            } else if ("begin_value".equals(kv[0])) {
-                beginValue = Long.valueOf(kv[1].trim());
-            } else if ("end_value".equals(kv[0])) {
-                endValue = Long.valueOf(kv[1].trim());
-            }
-        }
-        if (hasErrorCode) {
-            authorize();
-            result = HttpUtils.sendPost(accessUrl, param);
-            kvs = result.split("&");
-            for (String item : kvs) {
-                String[] kv = item.split("=");
-                if ("error_code".equals(kv[0])) {
+        Map<String, String> resultMap = parseHttpKvString(result);
+        if (resultMap.isEmpty()) {
+            return null;
+        } else {
+            if (resultMap.get("errorCode") != null) {
+                authorize();
+                result = HttpUtils.sendPost(accessUrl, param);
+                resultMap = parseHttpKvString(result);
+                if (resultMap.get("errorCode") != null) {
                     throw new GetSequenceFailedException("clientId:" + clientId
                                                          + " access data failed, return message is:" + result);
-                } else if ("begin_value".equals(kv[0])) {
-                    beginValue = Long.valueOf(kv[1].trim());
-                } else if ("end_value".equals(kv[0])) {
-                    endValue = Long.valueOf(kv[1].trim());
                 }
             }
+            SequenceRange sequenceRange = new SequenceRange();
+            sequenceRange.setBeginValue(parseLong(resultMap.get("beginValue")));
+            sequenceRange.setEndValue(parseLong(resultMap.get("endValue")));
+            return sequenceRange;
         }
-        SequenceRange sequenceRange = new SequenceRange();
-        sequenceRange.setBeginValue(beginValue);
-        sequenceRange.setEndValue(endValue);
-        return sequenceRange;
     }
 
     /**
-     * param: client_id=&client_token=
-     * return: access_url=http&access_token=1&error_code=1
+     * param: clientId= &clientToken=
+     * return: accessUrl= &accessToken= &errorCode= &errorMessage=
      */
     private void authorize() {
         Map<String, String> param = new HashMap<>();
-        param.put("client_id", clientId);
-        param.put("authorize_token", authorizeToken);
+        param.put("clientId", clientId);
+        param.put("authorizeToken", authorizeToken);
         String result = HttpUtils.sendPost(authorizeUrl, param);
-        String[] kvs = result.split("&");
-        for (String item : kvs) {
-            String[] kv = item.split("=");
-            if ("error_code".equals(kv[0]) && kv.length >= 2 && kv[1] != null && kv[1].trim().length() > 0) {
+        Map<String, String> resultMap = parseHttpKvString(result);
+        if (resultMap.isEmpty()) {
+            throw new GetSequenceFailedException("clientId:" + clientId + " authorize failed, return message is empty");
+        } else {
+            if (resultMap.get("errorCode") != null) {
                 throw new GetSequenceFailedException("clientId:" + clientId + " authorize failed, return message is: "
                                                      + result);
-            } else if ("access_url".equals(kv[0])) {
-                this.accessUrl = kv[1];
-            } else if ("access_token".equals(kv[0])) {
-                this.accessToken = kv[1];
             }
-        }
-        if (accessUrl != null) {
+            String accessUrl = resultMap.get("accessUrl");
+            String accessToken = resultMap.get("accessToken");
+            if (accessUrl == null || accessToken == null) {
+                throw new GetSequenceFailedException(
+                                                     "clientId:"
+                                                             + clientId
+                                                             + " authorize failed, accessUrl or accessToken is null, detail message is "
+                                                             + result);
+            }
             try {
                 accessUrl = URLDecoder.decode(accessUrl.trim(), "UTF-8");
             } catch (UnsupportedEncodingException e) {
-                throw new RuntimeException(e);
+                throw new GetSequenceFailedException(e);
+            }
+            this.accessUrl = accessUrl;
+            this.accessToken = accessToken;
+        }
+    }
+
+    private Map<String, String> parseHttpKvString(String string) {
+        if (string == null) {
+            return Collections.emptyMap();
+        }
+        string = string.trim();
+        if (string.length() == 0) {
+            return Collections.emptyMap();
+        }
+        Map<String, String> map = new HashMap<>();
+        String[] kvs = string.split("&");
+        for (String kvString : kvs) {
+            String[] kv = kvString.split("=");
+            if (kv.length == 2) {
+                String val = kv[1];
+                val = val.trim();
+                if (val.length() == 0) {
+                    val = null;
+                }
+                map.put(kv[0], val);
+            } else if (kv.length == 1) {
+                map.put(kv[0], null);
+            } else {
+                throw new RuntimeException("Illegaled http kv string:" + kvString);
             }
         }
-        if (accessToken != null) {
-            accessToken = accessToken.trim();
+        return map;
+    }
+
+    private Long parseLong(String str) {
+        if (str == null) {
+            return null;
         }
-        if (accessUrl == null || accessUrl.length() == 0 || accessToken == null || accessToken.length() == 0) {
-            throw new GetSequenceFailedException("clientId:" + clientId + " authorize failed, return message is: "
-                                                 + result);
+        str = str.trim();
+        if (str.length() == 0) {
+            return null;
         }
+        return Long.parseLong(str);
     }
 
     static class HttpUtils {