diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/example/AppStore.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/AppStore.java
index 504e6d2..fcc937b 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/example/AppStore.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/AppStore.java
@@ -3,11 +3,15 @@ package us.codecraft.webmagic.example;
 import us.codecraft.webmagic.Site;
 import us.codecraft.webmagic.model.OOSpider;
 import us.codecraft.webmagic.model.annotation.ExtractBy;
+import us.codecraft.webmagic.utils.Experimental;
+
+import java.util.List;
 
 /**
  * @author code4crafter@gmail.com
  * @since 0.4.1
  */
+@Experimental
 public class AppStore {
 
     @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$..trackName")
@@ -16,9 +20,17 @@ public class AppStore {
     @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$..description")
     private String description;
 
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$..userRatingCount")
+    private int userRatingCount;
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$..screenshotUrls",multi = true)
+    private List<String> screenshotUrls;
+
     public static void main(String[] args) {
         AppStore appStore = OOSpider.create(Site.me(), AppStore.class).<AppStore>get("http://itunes.apple.com/lookup?id=653350791&country=cn&entity=software");
         System.out.println(appStore.trackName);
         System.out.println(appStore.description);
+        System.out.println(appStore.userRatingCount);
+        System.out.println(appStore.screenshotUrls);
     }
 }
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepoApi.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepoApi.java
new file mode 100644
index 0000000..deacde7
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/GithubRepoApi.java
@@ -0,0 +1,70 @@
+package us.codecraft.webmagic.example;
+
+import us.codecraft.webmagic.Site;
+import us.codecraft.webmagic.model.ConsolePageModelPipeline;
+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.ExtractByUrl;
+
+import java.util.List;
+
+/**
+ * @author code4crafter@gmail.com <br>
+ * @since 0.4.1
+ */
+public class GithubRepoApi implements HasKey {
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$.name")
+    private String name;
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$..owner.login")
+    private String author;
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$.language",multi = true)
+    private List<String> language;
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$.stargazers_count")
+    private int star;
+
+    @ExtractBy(type = ExtractBy.Type.JsonPath, value = "$.forks_count")
+    private int fork;
+
+    @ExtractByUrl
+    private String url;
+
+    public static void main(String[] args) {
+        OOSpider.create(Site.me().setSleepTime(100)
+                , new ConsolePageModelPipeline(), GithubRepoApi.class)
+                .addUrl("https://api.github.com/repos/code4craft/webmagic").run();
+    }
+
+    @Override
+    public String key() {
+        return author + ":" + name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public List<String> getLanguage() {
+        return language;
+    }
+
+    public String getUrl() {
+        return url;
+    }
+
+    public int getStar() {
+        return star;
+    }
+
+    public int getFork() {
+        return fork;
+    }
+}
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/selector/JsonPathSelector.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/selector/JsonPathSelector.java
index 2270384..781669f 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/selector/JsonPathSelector.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/selector/JsonPathSelector.java
@@ -1,6 +1,7 @@
 package us.codecraft.webmagic.selector;
 
 import com.jayway.jsonpath.JsonPath;
+import us.codecraft.webmagic.utils.Experimental;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -12,6 +13,7 @@ import java.util.List;
  * @author code4crafter@gmail.com <br>
  * @since 0.2.1
  */
+@Experimental
 public class JsonPathSelector implements Selector {
 
     private String jsonPathStr;