diff --git a/webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepo.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepo.java
similarity index 66%
rename from webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepo.java
rename to webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepo.java
index a9e049b..d950115 100644
--- a/webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepo.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepo.java
@@ -1,10 +1,6 @@
-package us.codecraft.webmagic.model;
+package us.codecraft.webmagic.example;
 
-import junit.framework.Assert;
-import org.junit.Test;
-import us.codecraft.webmagic.MockDownloader;
-import us.codecraft.webmagic.Site;
-import us.codecraft.webmagic.Task;
+import us.codecraft.webmagic.model.HasKey;
 import us.codecraft.webmagic.model.annotation.ExtractBy;
 import us.codecraft.webmagic.model.annotation.ExtractByUrl;
 import us.codecraft.webmagic.model.annotation.HelpUrl;
@@ -25,10 +21,10 @@ public class GithubRepo implements HasKey {
     @ExtractByUrl("https://github\\.com/(\\w+)/.*")
     private String author;
 
-    @ExtractBy("//div[@id='readme']")
+    @ExtractBy("//div[@id='readme']/tidyText()")
     private String readme;
 
-    @ExtractBy(value = "//div[@class='repository-lang-stats']//li//span[@class='lang']", multi = true)
+    @ExtractBy(value = "//div[@class='repository-lang-stats']//li//span[@class='lang']/text()", multi = true)
     private List<String> language;
 
     @ExtractBy("//ul[@class='pagehead-actions']/li[2]//a[@class='social-count js-social-count']/text()")
@@ -40,18 +36,6 @@ public class GithubRepo implements HasKey {
     @ExtractByUrl
     private String url;
 
-    @Test
-    public void test() {
-        OOSpider.create(Site.me().addStartUrl("https://github.com/code4craft/webmagic").setSleepTime(0)
-                , new PageModelPipeline<GithubRepo>() {
-            @Override
-            public void process(GithubRepo o, Task task) {
-                Assert.assertEquals(78, o.getStar());
-                Assert.assertEquals(65, o.getFork());
-            }
-        }, GithubRepo.class).setDownloader(new MockDownloader()).test("https://github.com/code4craft/webmagic");
-    }
-
     @Override
     public String key() {
         return author + ":" + name;
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/PageModelExtractor.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/PageModelExtractor.java
index 370b0fb..cd3e72b 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/PageModelExtractor.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/PageModelExtractor.java
@@ -105,15 +105,15 @@ class PageModelExtractor {
         Formatter formatter = field.getAnnotation(Formatter.class);
         if (formatter != null) {
             if (!formatter.formatter().equals(ObjectFormatter.class)) {
-                return initFormatter(formatter);
+                return initFormatter(formatter.formatter());
             }
         }
-        return ObjectFormatters.get(fieldClazz);
+        return initFormatter(ObjectFormatters.get(fieldClazz));
     }
 
-    private ObjectFormatter initFormatter(Formatter formatter) {
+    private ObjectFormatter initFormatter(Class<? extends ObjectFormatter> formatterClazz) {
         try {
-            return formatter.formatter().newInstance();
+            return formatterClazz.newInstance();
         } catch (InstantiationException e) {
             logger.error("init ObjectFormatter fail", e);
         } catch (IllegalAccessException e) {
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/BasicTypeFormatter.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/BasicTypeFormatter.java
index 2669582..f9d76a8 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/BasicTypeFormatter.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/BasicTypeFormatter.java
@@ -25,9 +25,9 @@ public abstract class BasicTypeFormatter<T> implements ObjectFormatter<T> {
 
     protected abstract T formatTrimmed(String raw) throws Exception;
 
-    public static final List<ObjectFormatter> basicTypeFormatters = Arrays.<ObjectFormatter>asList(new IntegerFormatter(),
-            new LongFormatter(), new DoubleFormatter(), new FloatFormatter(), new ShortFormatter(),
-            new CharactorFormatter(), new ByteFormatter(), new BooleanFormatter());
+    public static final List<Class<? extends ObjectFormatter>> basicTypeFormatters = Arrays.<Class<? extends ObjectFormatter>>asList(IntegerFormatter.class,
+            LongFormatter.class, DoubleFormatter.class, FloatFormatter.class, ShortFormatter.class,
+            CharactorFormatter.class, ByteFormatter.class, BooleanFormatter.class);
 
     public static Class<?> detectBasicClass(Class<?> type) {
         if (type.equals(Integer.TYPE) || type.equals(Integer.class)) {
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/ObjectFormatters.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/ObjectFormatters.java
index 6dedc3c..7534e5e 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/ObjectFormatters.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/formatter/ObjectFormatters.java
@@ -9,19 +9,26 @@ import java.util.concurrent.ConcurrentHashMap;
  */
 public class ObjectFormatters {
 
-    private static Map<Class, ObjectFormatter> formatterMap = new ConcurrentHashMap<Class, ObjectFormatter>();
+    private static Map<Class, Class<? extends ObjectFormatter>> formatterMap = new ConcurrentHashMap<Class, Class<? extends ObjectFormatter>>();
 
     static {
-        for (ObjectFormatter basicTypeFormatter : BasicTypeFormatter.basicTypeFormatters) {
+        for (Class<? extends ObjectFormatter> basicTypeFormatter : BasicTypeFormatter.basicTypeFormatters) {
             put(basicTypeFormatter);
         }
+        put(DateFormatter.class);
+    }
+
+    public static void put(Class<? extends ObjectFormatter> objectFormatter) {
+        try {
+            formatterMap.put(objectFormatter.newInstance().clazz(), objectFormatter);
+        } catch (InstantiationException e) {
+            e.printStackTrace();
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
     }
 
-    public static void put(ObjectFormatter objectFormatter) {
-        formatterMap.put(objectFormatter.clazz(), objectFormatter);
-    }
-
-    public static <T> ObjectFormatter<T> get(Class<T> clazz){
+    public static Class<? extends ObjectFormatter> get(Class<?> clazz){
         return formatterMap.get(clazz);
     }
 }
diff --git a/webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepoTest.java b/webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepoTest.java
new file mode 100644
index 0000000..9755550
--- /dev/null
+++ b/webmagic-extension/src/test/java/us/codecraft/webmagic/model/GithubRepoTest.java
@@ -0,0 +1,26 @@
+package us.codecraft.webmagic.model;
+
+import junit.framework.Assert;
+import org.junit.Test;
+import us.codecraft.webmagic.MockDownloader;
+import us.codecraft.webmagic.Site;
+import us.codecraft.webmagic.Task;
+import us.codecraft.webmagic.example.GithubRepo;
+
+/**
+ * @author code4crafter@gmail.com <br>
+ */
+public class GithubRepoTest {
+
+    @Test
+    public void test() {
+        OOSpider.create(Site.me().addStartUrl("https://github.com/code4craft/webmagic").setSleepTime(0)
+                , new PageModelPipeline<GithubRepo>() {
+            @Override
+            public void process(GithubRepo o, Task task) {
+                Assert.assertEquals(78, o.getStar());
+                Assert.assertEquals(65, o.getFork());
+            }
+        }, GithubRepo.class).setDownloader(new MockDownloader()).test("https://github.com/code4craft/webmagic");
+    }
+}
diff --git a/webmagic-samples/src/main/java/us/codecraft/webmagic/model/samples/OschinaBlog.java b/webmagic-samples/src/main/java/us/codecraft/webmagic/model/samples/OschinaBlog.java
index 7819b44..8e6602c 100644
--- a/webmagic-samples/src/main/java/us/codecraft/webmagic/model/samples/OschinaBlog.java
+++ b/webmagic-samples/src/main/java/us/codecraft/webmagic/model/samples/OschinaBlog.java
@@ -1,19 +1,19 @@
 package us.codecraft.webmagic.model.samples;
 
 import us.codecraft.webmagic.Site;
-import us.codecraft.webmagic.model.HasKey;
 import us.codecraft.webmagic.model.OOSpider;
 import us.codecraft.webmagic.model.annotation.ExtractBy;
 import us.codecraft.webmagic.model.annotation.TargetUrl;
 import us.codecraft.webmagic.pipeline.JsonFilePageModelPipeline;
 
+import java.util.Date;
 import java.util.List;
 
 /**
  * @author code4crafter@gmail.com <br>
  */
 @TargetUrl("http://my.oschina.net/flashsword/blog/\\d+")
-public class OschinaBlog implements HasKey{
+public class OschinaBlog{
 
     @ExtractBy("//title")
     private String title;
@@ -24,16 +24,14 @@ public class OschinaBlog implements HasKey{
     @ExtractBy(value = "//div[@class='BlogTags']/a/text()", multi = true)
     private List<String> tags;
 
+    @ExtractBy("//div[class='BlogStat']/regex('\\d{4}-\\d{1,2}-\\d{1,2} \\d{1,2}:\\d{1,2}')")
+    private Date date;
+
     public static void main(String[] args) {
         OOSpider.create(Site.me().addStartUrl("http://my.oschina.net/flashsword/blog")
                 ,new JsonFilePageModelPipeline(), OschinaBlog.class).run();
     }
 
-    @Override
-    public String key() {
-        return title;
-    }
-
     public String getTitle() {
         return title;
     }