diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/Version.java b/dubbo-common/src/main/java/org/apache/dubbo/common/Version.java
index 099b2bb536e..6872e241f82 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/Version.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/Version.java
@@ -21,6 +21,7 @@
 import org.apache.dubbo.common.utils.ClassHelper;
 import org.apache.dubbo.common.utils.StringUtils;
 
+import java.io.IOException;
 import java.net.URL;
 import java.security.CodeSource;
 import java.util.Enumeration;
@@ -28,12 +29,16 @@
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * Version
  */
 public final class Version {
     private static final Logger logger = LoggerFactory.getLogger(Version.class);
+    
+    private static final Pattern PREFIX_DIGITS_PATTERN = Pattern.compile("^([0-9]*).*");
 
     // Dubbo RPC protocol version, for compatibility, it must not be between 2.0.10 ~ 2.6.2
     public static final String DEFAULT_DUBBO_PROTOCOL_VERSION = "2.0.2";
@@ -120,73 +125,47 @@ private static int parseInt(String version) {
         String[] vArr = version.split("\\.");
         int len = vArr.length;
         for (int i = 0; i < len; i++) {
-            v += Integer.parseInt(getDigital(vArr[i])) * Math.pow(10, (len - i - 1) * 2);
+            v += Integer.parseInt(getPrefixDigits(vArr[i])) * Math.pow(10, (len - i - 1) * 2);
         }
         return v;
     }
 
-    private static String getDigital(String v) {
-        int index = 0;
-        for (int i = 0; i < v.length(); i++) {
-            char c = v.charAt(i);
-            if (Character.isDigit(c)) {
-                if (i == v.length() - 1) {
-                    index = i + 1;
-                } else {
-                    index = i;
-                }
-            } else {
-                index = i;
-                break;
-            }
-        }
-        return v.substring(0, index);
-    }
-
-    private static boolean hasResource(String path) {
-        try {
-            return Version.class.getClassLoader().getResource(path) != null;
-        } catch (Throwable t) {
-            return false;
+    /**
+     * get prefix digits from given version string
+     */
+    private static String getPrefixDigits(String v) {
+        Matcher matcher = PREFIX_DIGITS_PATTERN.matcher(v);
+        if (matcher.find()) {
+            return matcher.group(1);
         }
+        return "";
     }
 
     public static String getVersion(Class<?> cls, String defaultVersion) {
         try {
             // find version info from MANIFEST.MF first
             String version = cls.getPackage().getImplementationVersion();
-            if (StringUtils.isEmpty(version)) {
-                version = cls.getPackage().getSpecificationVersion();
+            if (!StringUtils.isEmpty(version)) {
+                return version;
             }
-            if (StringUtils.isEmpty(version)) {
-                // guess version fro jar file name if nothing's found from MANIFEST.MF
-                CodeSource codeSource = cls.getProtectionDomain().getCodeSource();
-                if (codeSource == null) {
-                    logger.info("No codeSource for class " + cls.getName() + " when getVersion, use default version " + defaultVersion);
-                } else {
-                    String file = codeSource.getLocation().getFile();
-                    if (file != null && file.length() > 0 && file.endsWith(".jar")) {
-                        file = file.substring(0, file.length() - 4);
-                        int i = file.lastIndexOf('/');
-                        if (i >= 0) {
-                            file = file.substring(i + 1);
-                        }
-                        i = file.indexOf("-");
-                        if (i >= 0) {
-                            file = file.substring(i + 1);
-                        }
-                        while (file.length() > 0 && !Character.isDigit(file.charAt(0))) {
-                            i = file.indexOf("-");
-                            if (i >= 0) {
-                                file = file.substring(i + 1);
-                            } else {
-                                break;
-                            }
-                        }
-                        version = file;
-                    }
-                }
+            
+            version = cls.getPackage().getSpecificationVersion();
+            if (!StringUtils.isEmpty(version)) {
+                return version;
+            }
+            
+            // guess version fro jar file name if nothing's found from MANIFEST.MF
+            CodeSource codeSource = cls.getProtectionDomain().getCodeSource();
+            if (codeSource == null) {
+                logger.info("No codeSource for class " + cls.getName() + " when getVersion, use default version " + defaultVersion);
+                return defaultVersion;
+            } 
+            
+            String file = codeSource.getLocation().getFile();
+            if (!StringUtils.isEmpty(file) && file.endsWith(".jar")) {
+                version = getFromFile(file);
             }
+            
             // return default version if no version info is found
             return StringUtils.isEmpty(version) ? defaultVersion : version;
         } catch (Throwable e) {
@@ -196,6 +175,37 @@ public static String getVersion(Class<?> cls, String defaultVersion) {
         }
     }
 
+    /**
+     * get version from file: path/to/group-module-x.y.z.jar, returns x.y.z
+     */
+    private static String getFromFile(String file) {
+        // remove suffix ".jar": "path/to/group-module-x.y.z"
+        file = file.substring(0, file.length() - 4);
+        
+        // remove path: "group-module-x.y.z"
+        int i = file.lastIndexOf('/');
+        if (i >= 0) {
+            file = file.substring(i + 1);
+        }
+        
+        // remove group: "module-x.y.z"
+        i = file.indexOf("-");
+        if (i >= 0) {
+            file = file.substring(i + 1);
+        }
+        
+        // remove module: "x.y.z"
+        while (file.length() > 0 && !Character.isDigit(file.charAt(0))) {
+            i = file.indexOf("-");
+            if (i >= 0) {
+                file = file.substring(i + 1);
+            } else {
+                break;
+            }
+        }
+        return file;
+    }
+
     public static void checkDuplicate(Class<?> cls, boolean failOnError) {
         checkDuplicate(cls.getName().replace('.', '/') + ".class", failOnError);
     }
@@ -207,17 +217,7 @@ public static void checkDuplicate(Class<?> cls) {
     public static void checkDuplicate(String path, boolean failOnError) {
         try {
             // search in caller's classloader
-            Enumeration<URL> urls = ClassHelper.getCallerClassLoader(Version.class).getResources(path);
-            Set<String> files = new HashSet<String>();
-            while (urls.hasMoreElements()) {
-                URL url = urls.nextElement();
-                if (url != null) {
-                    String file = url.getFile();
-                    if (file != null && file.length() > 0) {
-                        files.add(file);
-                    }
-                }
-            }
+            Set<String> files = getResources(path);
             // duplicated jar is found
             if (files.size() > 1) {
                 String error = "Duplicate class " + path + " in " + files.size() + " jar " + files;
@@ -232,4 +232,22 @@ public static void checkDuplicate(String path, boolean failOnError) {
         }
     }
 
+    /**
+     * search resources in caller's classloader
+     */
+    private static Set<String> getResources(String path) throws IOException {
+        Enumeration<URL> urls = ClassHelper.getCallerClassLoader(Version.class).getResources(path);
+        Set<String> files = new HashSet<String>();
+        while (urls.hasMoreElements()) {
+            URL url = urls.nextElement();
+            if (url != null) {
+                String file = url.getFile();
+                if (file != null && file.length() > 0) {
+                    files.add(file);
+                }
+            }
+        }
+        return files;
+    }
+
 }