diff --git a/webmagic-extension/pom.xml b/webmagic-extension/pom.xml
index a234a4f..8d2c070 100644
--- a/webmagic-extension/pom.xml
+++ b/webmagic-extension/pom.xml
@@ -10,6 +10,12 @@
     <artifactId>webmagic-extension</artifactId>
 
     <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.32</version>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>redis.clients</groupId>
             <artifactId>jedis</artifactId>
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/Extractor.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/Extractor.java
index f1d2f84..d64adff 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/Extractor.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/Extractor.java
@@ -1,5 +1,7 @@
 package us.codecraft.webmagic.model;
 
+import lombok.Getter;
+import lombok.Setter;
 import us.codecraft.webmagic.selector.Selector;
 
 /**
@@ -7,17 +9,19 @@ import us.codecraft.webmagic.selector.Selector;
  * @author code4crafter@gmail.com <br>
  * @since 0.2.0
  */
-class Extractor {
+public class Extractor {
 
+    @Getter @Setter
     protected Selector selector;
 
+    @Getter
     protected final Source source;
 
     protected final boolean notNull;
 
     protected final boolean multi;
 
-    static enum Source {Html, Url, RawHtml, RawText}
+    public static enum Source {Html, Url, RawHtml, RawText}
 
     public Extractor(Selector selector, Source source, boolean notNull, boolean multi) {
         this.selector = selector;
@@ -26,23 +30,11 @@ class Extractor {
         this.multi = multi;
     }
 
-    Selector getSelector() {
-        return selector;
-    }
-
-    Source getSource() {
-        return source;
-    }
-
-    boolean isNotNull() {
+    public boolean isNotNull() {
         return notNull;
     }
 
-    boolean isMulti() {
+    public boolean isMulti() {
         return multi;
     }
-
-    void setSelector(Selector selector) {
-        this.selector = selector;
-    }
 }
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/FieldExtractor.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/FieldExtractor.java
index a2cba13..a49ea77 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/FieldExtractor.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/FieldExtractor.java
@@ -6,53 +6,27 @@ import us.codecraft.webmagic.selector.Selector;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 
+import lombok.Getter;
+import lombok.Setter;
+
 /**
  * Wrapper of field and extractor.
  * @author code4crafter@gmail.com <br>
  * @since 0.2.0
  */
-class FieldExtractor extends Extractor {
+public class FieldExtractor extends Extractor {
 
+    @Getter
     private final Field field;
 
+    @Getter @Setter
     private Method setterMethod;
 
+    @Getter @Setter
     private ObjectFormatter objectFormatter;
 
     public FieldExtractor(Field field, Selector selector, Source source, boolean notNull, boolean multi) {
         super(selector, source, notNull, multi);
         this.field = field;
     }
-
-    Field getField() {
-        return field;
-    }
-
-    Selector getSelector() {
-        return selector;
-    }
-
-    Source getSource() {
-        return source;
-    }
-
-    void setSetterMethod(Method setterMethod) {
-        this.setterMethod = setterMethod;
-    }
-
-    Method getSetterMethod() {
-        return setterMethod;
-    }
-
-    boolean isNotNull() {
-        return notNull;
-    }
-
-    ObjectFormatter getObjectFormatter() {
-        return objectFormatter;
-    }
-
-    void setObjectFormatter(ObjectFormatter objectFormatter) {
-        this.objectFormatter = objectFormatter;
-    }
 }
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 d8947de..de71717 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
@@ -3,17 +3,21 @@ package us.codecraft.webmagic.model;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
+import lombok.Getter;
 import us.codecraft.webmagic.Page;
 import us.codecraft.webmagic.model.annotation.*;
-import us.codecraft.webmagic.model.formatter.ObjectFormatter;
+import us.codecraft.webmagic.model.fields.PageField;
 import us.codecraft.webmagic.model.formatter.ObjectFormatterBuilder;
+import us.codecraft.webmagic.model.selections.MultipleSelection;
+import us.codecraft.webmagic.model.selections.Selection;
+import us.codecraft.webmagic.model.selections.SingleSelection;
 import us.codecraft.webmagic.selector.*;
 import us.codecraft.webmagic.utils.ClassUtils;
 import us.codecraft.webmagic.utils.ExtractorUtils;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
@@ -29,14 +33,19 @@ import static us.codecraft.webmagic.model.annotation.ExtractBy.Source.RawText;
  */
 class PageModelExtractor {
 
+    @Getter
     private List<Pattern> targetUrlPatterns = new ArrayList<Pattern>();
 
+    @Getter
     private Selector targetUrlRegionSelector;
 
+    @Getter
     private List<Pattern> helpUrlPatterns = new ArrayList<Pattern>();
 
+    @Getter
     private Selector helpUrlRegionSelector;
 
+    @Getter
     private Class clazz;
 
     private List<FieldExtractor> fieldExtractors;
@@ -233,145 +242,16 @@ class PageModelExtractor {
         try {
             o = clazz.newInstance();
             for (FieldExtractor fieldExtractor : fieldExtractors) {
-                if (fieldExtractor.isMulti()) {
-                    List<String> value=getMultiValueFromSource(page, fieldExtractor, html, isRaw);
-                    if ((value == null || value.size() == 0) && fieldExtractor.isNotNull()) {
-                        return null;
-                    }
-                    if (fieldExtractor.getObjectFormatter() != null) {
-                        List<Object> converted = convertMultiValue(value, fieldExtractor.getObjectFormatter());
-                        setField(o, fieldExtractor, converted);
-                    } else {
-                        setField(o, fieldExtractor, value);
-                    }
-                } else {
-                    String value=getSingleValueFromSource(page, fieldExtractor, html, isRaw);
-                    if (value == null && fieldExtractor.isNotNull()) {
-                        return null;
-                    }
-                    if (fieldExtractor.getObjectFormatter() != null) {
-                        Object converted = convertSingleValue(value, fieldExtractor.getObjectFormatter());
-                        if (converted == null && fieldExtractor.isNotNull()) {
-                            return null;
-                        }
-                        setField(o, fieldExtractor, converted);
-                    } else {
-                        setField(o, fieldExtractor, value);
-                    }
-                }
+                Selection selection = fieldExtractor.isMulti() ? new MultipleSelection() : new SingleSelection();
+                PageField field = selection.extractField(page, html, isRaw, fieldExtractor);
+                if (!field.operation(o, fieldExtractor, logger))
+                    return null;
             }
-            if (AfterExtractor.class.isAssignableFrom(clazz)) {
+            if (AfterExtractor.class.isAssignableFrom(clazz))
                 ((AfterExtractor) o).afterProcess(page);
-            }
-        } catch (InstantiationException e) {
-            logger.error("extract fail", e);
-        } catch (IllegalAccessException e) {
-            logger.error("extract fail", e);
-        } catch (InvocationTargetException e) {
+        } catch (Exception e) {
             logger.error("extract fail", e);
         }
         return o;
     }
-
-    private List<String> getMultiValueFromSource(Page page, FieldExtractor fieldExtractor, String html, boolean isRaw) {
-        List<String> value;
-        switch (fieldExtractor.getSource()) {
-            case RawHtml:
-                value = page.getHtml().selectDocumentForList(fieldExtractor.getSelector());
-                break;
-            case Html:
-                if (isRaw) {
-                    value = page.getHtml().selectDocumentForList(fieldExtractor.getSelector());
-                } else {
-                    value = fieldExtractor.getSelector().selectList(html);
-                }
-                break;
-            case Url:
-                value = fieldExtractor.getSelector().selectList(page.getUrl().toString());
-                break;
-            case RawText:
-                value = fieldExtractor.getSelector().selectList(page.getRawText());
-                break;
-            default:
-                value = fieldExtractor.getSelector().selectList(html);
-        }
-        return value;
-    }
-
-    private String getSingleValueFromSource(Page page, FieldExtractor fieldExtractor, String html, boolean isRaw) {
-        String value;
-        switch (fieldExtractor.getSource()) {
-            case RawHtml:
-                value = page.getHtml().selectDocument(fieldExtractor.getSelector());
-                break;
-            case Html:
-                if (isRaw) {
-                    value = page.getHtml().selectDocument(fieldExtractor.getSelector());
-                } else {
-                    value = fieldExtractor.getSelector().select(html);
-                }
-                break;
-            case Url:
-                value = fieldExtractor.getSelector().select(page.getUrl().toString());
-                break;
-            case RawText:
-                value = fieldExtractor.getSelector().select(page.getRawText());
-                break;
-            default:
-                value = fieldExtractor.getSelector().select(html);
-        }
-        return value;
-    }
-
-    private Object convertSingleValue(String value, ObjectFormatter objectFormatter) {
-        try {
-            Object format = objectFormatter.format(value);
-            logger.debug("String {} is converted to {}", value, format);
-            return format;
-        } catch (Exception e) {
-            logger.error("convert " + value + " to " + objectFormatter.clazz() + " error!", e);
-        }
-        return null;
-    }
-
-    private List<Object> convertMultiValue(List<String> values, ObjectFormatter objectFormatter) {
-        List<Object> objects = new ArrayList<Object>();
-        for (String value : values) {
-            Object converted = convertSingleValue(value, objectFormatter);
-            if (converted != null) {
-                objects.add(converted);
-            }
-        }
-        return objects;
-    }
-
-    private void setField(Object o, FieldExtractor fieldExtractor, Object value) throws IllegalAccessException, InvocationTargetException {
-        if (value == null) {
-            return;
-        }
-        if (fieldExtractor.getSetterMethod() != null) {
-            fieldExtractor.getSetterMethod().invoke(o, value);
-        }
-        fieldExtractor.getField().set(o, value);
-    }
-
-    Class getClazz() {
-        return clazz;
-    }
-
-    List<Pattern> getTargetUrlPatterns() {
-        return targetUrlPatterns;
-    }
-
-    List<Pattern> getHelpUrlPatterns() {
-        return helpUrlPatterns;
-    }
-
-    Selector getTargetUrlRegionSelector() {
-        return targetUrlRegionSelector;
-    }
-
-    Selector getHelpUrlRegionSelector() {
-        return helpUrlRegionSelector;
-    }
 }
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/MultipleField.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/MultipleField.java
new file mode 100644
index 0000000..4a4bf38
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/MultipleField.java
@@ -0,0 +1,42 @@
+package us.codecraft.webmagic.model.fields;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.slf4j.Logger;
+
+import lombok.Getter;
+import us.codecraft.webmagic.model.FieldExtractor;
+import us.codecraft.webmagic.model.formatter.ObjectFormatter;
+
+public class MultipleField extends PageField {
+   @Getter
+   private List<String> fieldNames; 
+
+   public MultipleField(List<String> fieldNames) {
+      this.fieldNames = fieldNames;
+   }
+   
+   public boolean operation(Object o, FieldExtractor fieldExtractor, Logger logger) throws IllegalAccessException, InvocationTargetException {
+      if ((this.fieldNames == null || this.fieldNames.size() == 0) && fieldExtractor.isNotNull())
+         return false;
+      if (fieldExtractor.getObjectFormatter() != null) {
+         List<Object> converted = this.convert(this.fieldNames, fieldExtractor.getObjectFormatter(), logger);
+         setField(o, fieldExtractor, converted);
+      }
+      else
+         setField(o, fieldExtractor, this.fieldNames);
+      return true;
+   }
+
+   private List<Object> convert(List<String> values, ObjectFormatter objectFormatter, Logger logger) {
+      List<Object> objects = new ArrayList<>();
+      for (String value : values) {
+          Object converted = this.convert(value, objectFormatter, logger);
+          if (converted != null)
+              objects.add(converted);
+      }
+      return objects;
+  }
+}
\ No newline at end of file
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/PageField.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/PageField.java
new file mode 100644
index 0000000..ad44283
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/PageField.java
@@ -0,0 +1,31 @@
+package us.codecraft.webmagic.model.fields;
+
+import java.lang.reflect.InvocationTargetException;
+
+import org.slf4j.Logger;
+
+import us.codecraft.webmagic.model.FieldExtractor;
+import us.codecraft.webmagic.model.formatter.ObjectFormatter;
+
+public abstract class PageField {
+   public abstract boolean operation(Object o, FieldExtractor fieldExtractor, Logger logger) throws IllegalAccessException, InvocationTargetException;
+
+   protected Object convert(String value, ObjectFormatter objectFormatter, Logger logger) {
+      try {
+         Object format = objectFormatter.format(value);
+         logger.debug("String {} is converted to {}", value, format);
+         return format;
+      } catch (Exception e) {
+            logger.error("convert " + value + " to " + objectFormatter.clazz() + " error!", e);
+      }
+      return null;
+   }
+
+   protected void setField(Object o, FieldExtractor fieldExtractor, Object value) throws IllegalAccessException, InvocationTargetException {
+      if (value != null) {
+         if (fieldExtractor.getSetterMethod() != null)
+            fieldExtractor.getSetterMethod().invoke(o, value);
+         fieldExtractor.getField().set(o, value);
+      }
+   }
+}
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/SingleField.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/SingleField.java
new file mode 100644
index 0000000..136a1c5
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/fields/SingleField.java
@@ -0,0 +1,28 @@
+package us.codecraft.webmagic.model.fields;
+
+import java.lang.reflect.InvocationTargetException;
+
+import org.slf4j.Logger;
+
+import lombok.Getter;
+import us.codecraft.webmagic.model.FieldExtractor;
+
+public class SingleField extends PageField {
+   @Getter
+   private String fieldName; 
+
+   public SingleField(String fieldName) {
+      this.fieldName = fieldName;
+   }
+
+   public boolean operation(Object o, FieldExtractor fieldExtractor, Logger logger) throws IllegalAccessException, InvocationTargetException {
+      if (fieldExtractor.getObjectFormatter() != null) {
+         Object converted = this.convert(this.fieldName, fieldExtractor.getObjectFormatter(), logger);
+         if (converted == null && fieldExtractor.isNotNull())
+            return false;
+         setField(o, fieldExtractor, converted);
+      } else
+         setField(o, fieldExtractor, this.fieldName);
+      return true;
+   }
+}
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/MultipleSelection.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/MultipleSelection.java
new file mode 100644
index 0000000..d49f9c5
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/MultipleSelection.java
@@ -0,0 +1,36 @@
+package us.codecraft.webmagic.model.selections;
+
+import java.util.List;
+
+import us.codecraft.webmagic.Page;
+import us.codecraft.webmagic.model.FieldExtractor;
+import us.codecraft.webmagic.model.fields.MultipleField;
+
+public class MultipleSelection implements Selection {
+   public MultipleField extractField(Page page, String html, boolean isRaw, FieldExtractor fieldExtractor) {
+      List<String> fieldsName;
+      switch (fieldExtractor.getSource()) {
+         case RawHtml:
+            fieldsName = page.getHtml().selectDocumentForList(fieldExtractor.getSelector());
+            break;
+         case Html:
+            if (isRaw)
+               fieldsName = page.getHtml().selectDocumentForList(fieldExtractor.getSelector());
+            else
+               fieldsName = fieldExtractor.getSelector().selectList(html);
+            break;
+         case Url:
+            fieldsName = fieldExtractor.getSelector().selectList(page.getUrl().toString());
+            break;
+         case RawText:
+            fieldsName = fieldExtractor.getSelector().selectList(page.getRawText());
+            break;
+         default:
+            fieldsName = fieldExtractor.getSelector().selectList(html);
+      }
+      if ((fieldsName == null || fieldsName.size() == 0) && fieldExtractor.isNotNull()) {
+         return null;
+      }
+      return new MultipleField(fieldsName);
+   }
+}
\ No newline at end of file
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/Selection.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/Selection.java
new file mode 100644
index 0000000..e70ab9d
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/Selection.java
@@ -0,0 +1,9 @@
+package us.codecraft.webmagic.model.selections;
+
+import us.codecraft.webmagic.Page;
+import us.codecraft.webmagic.model.FieldExtractor;
+import us.codecraft.webmagic.model.fields.PageField;
+
+public interface Selection {
+   public PageField extractField(Page page, String html, boolean isRaw, FieldExtractor fieldExtractor);
+}
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/SingleSelection.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/SingleSelection.java
new file mode 100644
index 0000000..a4c1fe4
--- /dev/null
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/model/selections/SingleSelection.java
@@ -0,0 +1,33 @@
+package us.codecraft.webmagic.model.selections;
+
+import us.codecraft.webmagic.Page;
+import us.codecraft.webmagic.model.FieldExtractor;
+import us.codecraft.webmagic.model.fields.SingleField;
+
+public class SingleSelection implements Selection {
+    public SingleField extractField(Page page, String html, boolean isRaw, FieldExtractor fieldExtractor) {
+        String field;
+        switch (fieldExtractor.getSource()) {
+            case RawHtml:
+                field = page.getHtml().selectDocument(fieldExtractor.getSelector());
+                break;
+            case Html:
+                if (isRaw)
+                    field = page.getHtml().selectDocument(fieldExtractor.getSelector());
+                else
+                    field = fieldExtractor.getSelector().select(html);
+                break;
+            case Url:
+                field = fieldExtractor.getSelector().select(page.getUrl().toString());
+                break;
+            case RawText:
+                field = fieldExtractor.getSelector().select(page.getRawText());
+                break;
+            default:
+                field = fieldExtractor.getSelector().select(html);
+        }
+        if (field == null && fieldExtractor.isNotNull())
+            return null;
+        return new SingleField(field);
+    }
+}
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/utils/DoubleKeyMap.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/utils/DoubleKeyMap.java
old mode 100755
new mode 100644
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/utils/MultiKeyMapBase.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/utils/MultiKeyMapBase.java
old mode 100755
new mode 100644