diff --git a/README.md b/README.md
index d2be8ea..aab022e 100644
--- a/README.md
+++ b/README.md
@@ -16,9 +16,12 @@ Current we already have three RatingBars :
 ![](images/screenshot.png)  
 Icon made by [Freepik](http://www.freepik.com/) from www.flaticon.com 
 
-## What's New (v1.3.4)
-- Fix AnimationRatingBar out of sync bug.
+## What's New (v1.3.5)
+- Rename the attributes for more easily know all this library's attributes.  
+    (`app:rating="2"` change to `app:srb_rating="2"`)
 - Implement IsIndicator, Scrollable and Clickable settings.
+- Fix Handler null pointer bug.
+- Fix AnimationRatingBar out of sync bug.
 
 ## Feature
 - Allow half star through click event. (contributed by [ANPez](https://github.com/ANPez))
@@ -48,7 +51,7 @@ allprojects {
 }
 
 dependencies {
-    compile 'com.github.ome450901:SimpleRatingBar:1.3.4'
+    compile 'com.github.ome450901:SimpleRatingBar:1.3.5'
 }
 ```
 
@@ -56,22 +59,22 @@ dependencies {
 ### In Xml
 ```xml
 <com.willy.ratingbar.ScaleRatingBar
-        xmlns:rb="http://schemas.android.com/apk/res-auto"
+        xmlns:app="http://schemas.android.com/apk/res-auto"
         android:id="@+id/simpleRatingBar"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        rb:numStars="3"
-        rb:rating="2"
-        rb:starWidth="30dp"
-        rb:starHeight="30dp"
-        rb:starPadding="15dp"
-        rb:stepSize="0.5"
-        rb:isIndicator="false"
-        rb:clickable="true"
-        rb:scrollable="true"
-        rb:clearRatingEnabled="true"
-        rb:drawableEmpty="@drawable/start_empty"
-        rb:drawableFilled="@drawable/star_filled">
+        app:srb_numStars="3"
+        app:srb_rating="2"
+        app:srb_starWidth="30dp"
+        app:srb_starHeight="30dp"
+        app:srb_starPadding="15dp"
+        app:srb_stepSize="0.5"
+        app:srb_isIndicator="false"
+        app:srb_clickable="true"
+        app:srb_scrollable="true"
+        app:srb_clearRatingEnabled="true"
+        app:srb_drawableEmpty="@drawable/start_empty"
+        app:srb_drawableFilled="@drawable/star_filled">
 </com.willy.ratingbar.ScaleRatingBar>
 ```
 
diff --git a/example/src/main/res/layout/fragment_demo.xml b/example/src/main/res/layout/fragment_demo.xml
index e827739..e80669d 100644
--- a/example/src/main/res/layout/fragment_demo.xml
+++ b/example/src/main/res/layout/fragment_demo.xml
@@ -1,12 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:rb="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/layout"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    tools:context="com.willy.example.MainActivity">
+    android:layout_height="match_parent">
 
     <TextView
         android:id="@+id/textview_main_baseratingbar_title"
@@ -32,9 +29,9 @@
         app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintRight_toRightOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/textview_main_baseratingbar_title"
-        rb:numStars="7"
-        rb:rating="2.5"
-        rb:starPadding="5dp" />
+        app:srb_numStars="7"
+        app:srb_rating="2.5"
+        app:srb_starPadding="5dp" />
 
     <TextView
         android:id="@+id/textview_main_scaleratingbar_title"
@@ -60,8 +57,9 @@
         app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintRight_toRightOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/textview_main_scaleratingbar_title"
-        rb:starPadding="10dp"
-        rb:stepSize="0.5" />
+        app:srb_starPadding="10dp"
+        app:srb_rating="4"
+        app:srb_stepSize="0.5" />
 
     <TextView
         android:id="@+id/textview_main_rotationratingbar_title"
diff --git a/library/src/main/java/com/willy/ratingbar/AnimationRatingBar.java b/library/src/main/java/com/willy/ratingbar/AnimationRatingBar.java
index 2d6dd55..d3acb0d 100644
--- a/library/src/main/java/com/willy/ratingbar/AnimationRatingBar.java
+++ b/library/src/main/java/com/willy/ratingbar/AnimationRatingBar.java
@@ -2,9 +2,12 @@
 
 import android.content.Context;
 import android.os.Handler;
+import android.os.SystemClock;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 
+import java.util.UUID;
+
 /**
  * Created by willy on 2017/5/5.
  */
@@ -13,7 +16,7 @@ public class AnimationRatingBar extends BaseRatingBar {
 
     protected Handler mHandler;
     protected Runnable mRunnable;
-    protected String mRunnableToken = "AnimationRatingBar";
+    protected String mRunnableToken = UUID.randomUUID().toString();
 
     protected AnimationRatingBar(Context context) {
         super(context);
@@ -34,5 +37,14 @@ private void init() {
         mHandler = new Handler();
     }
 
+    protected void postRunnable(Runnable runnable, long ANIMATION_DELAY) {
+        if (mHandler == null) {
+            mHandler = new Handler();
+        }
+
+        long timeMillis = SystemClock.uptimeMillis() + ANIMATION_DELAY;
+        mHandler.postAtTime(runnable, mRunnableToken, timeMillis);
+    }
+
 }
 
diff --git a/library/src/main/java/com/willy/ratingbar/BaseRatingBar.java b/library/src/main/java/com/willy/ratingbar/BaseRatingBar.java
index 0893b05..fbf377d 100644
--- a/library/src/main/java/com/willy/ratingbar/BaseRatingBar.java
+++ b/library/src/main/java/com/willy/ratingbar/BaseRatingBar.java
@@ -34,7 +34,7 @@ public interface OnRatingChangeListener {
     private static final int MAX_CLICK_DISTANCE = 5;
     private static final int MAX_CLICK_DURATION = 200;
 
-    private final DecimalFormat mDecimalFormat;
+    private DecimalFormat mDecimalFormat;
 
     private int mNumStars;
     private int mPadding = 0;
@@ -76,31 +76,30 @@ public BaseRatingBar(Context context, @Nullable AttributeSet attrs) {
     public BaseRatingBar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
 
-        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RatingBarAttributes);
-        float rating = typedArray.getFloat(R.styleable.RatingBarAttributes_rating, mRating);
-        mNumStars = typedArray.getInt(R.styleable.RatingBarAttributes_numStars, mNumStars);
-        mPadding = typedArray.getDimensionPixelSize(R.styleable.RatingBarAttributes_starPadding, mPadding);
-        mStarWidth = typedArray.getDimensionPixelSize(R.styleable.RatingBarAttributes_starWidth, 0);
-        mStarHeight = typedArray.getDimensionPixelSize(R.styleable.RatingBarAttributes_starHeight, 0);
-        mStepSize = typedArray.getFloat(R.styleable.RatingBarAttributes_stepSize, mStepSize);
-        mEmptyDrawable = typedArray.hasValue(R.styleable.RatingBarAttributes_drawableEmpty) ? ContextCompat.getDrawable(context, typedArray.getResourceId(R.styleable.RatingBarAttributes_drawableEmpty, View.NO_ID)) : null;
-        mFilledDrawable = typedArray.hasValue(R.styleable.RatingBarAttributes_drawableFilled) ? ContextCompat.getDrawable(context, typedArray.getResourceId(R.styleable.RatingBarAttributes_drawableFilled, View.NO_ID)) : null;
-        mIsIndicator = typedArray.getBoolean(R.styleable.RatingBarAttributes_isIndicator, mIsIndicator);
-        mIsScrollable = typedArray.getBoolean(R.styleable.RatingBarAttributes_scrollable, mIsScrollable);
-        mIsClickable = typedArray.getBoolean(R.styleable.RatingBarAttributes_clickable, mIsClickable);
-        mClearRatingEnabled = typedArray.getBoolean(R.styleable.RatingBarAttributes_clearRatingEnabled, mClearRatingEnabled);
-        typedArray.recycle();
-
-        DecimalFormatSymbols symbols = new DecimalFormatSymbols();
-        symbols.setDecimalSeparator('.');
-        mDecimalFormat = new DecimalFormat("#.##", symbols);
+        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.BaseRatingBar);
+        final float rating = typedArray.getFloat(R.styleable.BaseRatingBar_srb_rating, 0);
 
+        initParamsValue(typedArray, context);
         verifyParamsValue();
-
         initRatingView();
         setRating(rating);
     }
 
+    private void initParamsValue(TypedArray typedArray, Context context) {
+        mNumStars = typedArray.getInt(R.styleable.BaseRatingBar_srb_numStars, mNumStars);
+        mPadding = typedArray.getDimensionPixelSize(R.styleable.BaseRatingBar_srb_starPadding, mPadding);
+        mStarWidth = typedArray.getDimensionPixelSize(R.styleable.BaseRatingBar_srb_starWidth, 0);
+        mStarHeight = typedArray.getDimensionPixelSize(R.styleable.BaseRatingBar_srb_starHeight, 0);
+        mStepSize = typedArray.getFloat(R.styleable.BaseRatingBar_srb_stepSize, mStepSize);
+        mEmptyDrawable = typedArray.hasValue(R.styleable.BaseRatingBar_srb_drawableEmpty) ? ContextCompat.getDrawable(context, typedArray.getResourceId(R.styleable.BaseRatingBar_srb_drawableEmpty, View.NO_ID)) : null;
+        mFilledDrawable = typedArray.hasValue(R.styleable.BaseRatingBar_srb_drawableFilled) ? ContextCompat.getDrawable(context, typedArray.getResourceId(R.styleable.BaseRatingBar_srb_drawableFilled, View.NO_ID)) : null;
+        mIsIndicator = typedArray.getBoolean(R.styleable.BaseRatingBar_srb_isIndicator, mIsIndicator);
+        mIsScrollable = typedArray.getBoolean(R.styleable.BaseRatingBar_srb_scrollable, mIsScrollable);
+        mIsClickable = typedArray.getBoolean(R.styleable.BaseRatingBar_srb_clickable, mIsClickable);
+        mClearRatingEnabled = typedArray.getBoolean(R.styleable.BaseRatingBar_srb_clearRatingEnabled, mClearRatingEnabled);
+        typedArray.recycle();
+    }
+
     private void verifyParamsValue() {
         if (mNumStars <= 0) {
             mNumStars = 5;
@@ -142,7 +141,6 @@ private void initRatingView() {
 
     private PartialView getPartialView(final int ratingViewId, Drawable filledDrawable, Drawable emptyDrawable) {
         PartialView partialView = new PartialView(getContext());
-//        partialView.setId(ratingViewId);
         partialView.setTag(ratingViewId);
         partialView.setPadding(mPadding, mPadding, mPadding, mPadding);
         partialView.setFilledDrawable(filledDrawable);
@@ -329,9 +327,10 @@ private void handleMoveEvent(float eventX) {
     }
 
     private float calculateRating(float eventX, PartialView partialView) {
-        float ratioOfView = Float.parseFloat(mDecimalFormat.format((eventX - partialView.getLeft()) / partialView.getWidth()));
+        DecimalFormat decimalFormat = getDecimalFormat();
+        float ratioOfView = Float.parseFloat(decimalFormat.format((eventX - partialView.getLeft()) / partialView.getWidth()));
         float steps = Math.round(ratioOfView / mStepSize) * mStepSize;
-        return Float.parseFloat(mDecimalFormat.format((int) partialView.getTag() - (1 - steps)));
+        return Float.parseFloat(decimalFormat.format((int) partialView.getTag() - (1 - steps)));
     }
 
     private void handleClickEvent(float eventX) {
@@ -410,6 +409,15 @@ public void setStepSize(@FloatRange(from = 0.1, to = 1.0) float stepSize) {
         this.mStepSize = stepSize;
     }
 
+    public DecimalFormat getDecimalFormat() {
+        if (mDecimalFormat == null) {
+            DecimalFormatSymbols symbols = new DecimalFormatSymbols();
+            symbols.setDecimalSeparator('.');
+            mDecimalFormat = new DecimalFormat("#.##", symbols);
+        }
+        return mDecimalFormat;
+    }
+
     @Override
     protected Parcelable onSaveInstanceState() {
         Parcelable superState = super.onSaveInstanceState();
diff --git a/library/src/main/java/com/willy/ratingbar/RotationRatingBar.java b/library/src/main/java/com/willy/ratingbar/RotationRatingBar.java
index 8b26fdf..5ba4a7b 100644
--- a/library/src/main/java/com/willy/ratingbar/RotationRatingBar.java
+++ b/library/src/main/java/com/willy/ratingbar/RotationRatingBar.java
@@ -1,7 +1,6 @@
 package com.willy.ratingbar;
 
 import android.content.Context;
-import android.os.SystemClock;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
@@ -64,9 +63,7 @@ protected void fillRatingBar(final float rating) {
             }
 
             mRunnable = getAnimationRunnable(rating, partialView, ratingViewId, maxIntOfRating);
-
-            long timeMillis = SystemClock.uptimeMillis() + ANIMATION_DELAY;
-            mHandler.postAtTime(mRunnable, mRunnableToken, timeMillis);
+            postRunnable(mRunnable, ANIMATION_DELAY);
         }
     }
 
diff --git a/library/src/main/java/com/willy/ratingbar/ScaleRatingBar.java b/library/src/main/java/com/willy/ratingbar/ScaleRatingBar.java
index 2f11a41..f8faafd 100644
--- a/library/src/main/java/com/willy/ratingbar/ScaleRatingBar.java
+++ b/library/src/main/java/com/willy/ratingbar/ScaleRatingBar.java
@@ -1,7 +1,6 @@
 package com.willy.ratingbar;
 
 import android.content.Context;
-import android.os.SystemClock;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
@@ -64,9 +63,7 @@ protected void fillRatingBar(final float rating) {
             }
 
             mRunnable = getAnimationRunnable(rating, partialView, ratingViewId, maxIntOfRating);
-
-            long timeMillis = SystemClock.uptimeMillis() + ANIMATION_DELAY;
-            mHandler.postAtTime(mRunnable, mRunnableToken, timeMillis);
+            postRunnable(mRunnable, ANIMATION_DELAY);
         }
     }
 
diff --git a/library/src/main/res/values/attrs.xml b/library/src/main/res/values/attrs.xml
index 70b2d0b..d723454 100644
--- a/library/src/main/res/values/attrs.xml
+++ b/library/src/main/res/values/attrs.xml
@@ -1,18 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
-    <declare-styleable name="RatingBarAttributes">
-        <attr name="numStars" format="integer" />
-        <attr name="rating" format="float" />
-        <attr name="starPadding" format="dimension" />
-        <attr name="drawableEmpty" format="reference" />
-        <attr name="drawableFilled" format="reference" />
-        <attr name="isIndicator" format="boolean" />
-        <attr name="scrollable" format="boolean" />
-        <attr name="clickable" format="boolean" />
-        <attr name="clearRatingEnabled" format="boolean" />
-        <attr name="starWidth" format="dimension" />
-        <attr name="starHeight" format="dimension" />
-        <attr name="stepSize" format="float" />
+    <declare-styleable name="BaseRatingBar">
+        <attr name="srb_numStars" format="integer" />
+        <attr name="srb_rating" format="float" />
+        <attr name="srb_starPadding" format="dimension" />
+        <attr name="srb_drawableEmpty" format="reference" />
+        <attr name="srb_drawableFilled" format="reference" />
+        <attr name="srb_isIndicator" format="boolean" />
+        <attr name="srb_scrollable" format="boolean" />
+        <attr name="srb_clickable" format="boolean" />
+        <attr name="srb_clearRatingEnabled" format="boolean" />
+        <attr name="srb_starWidth" format="dimension" />
+        <attr name="srb_starHeight" format="dimension" />
+        <attr name="srb_stepSize" format="float" />
     </declare-styleable>
 </resources>
\ No newline at end of file