diff --git a/Phoenix/src/main/java/com/yalantis/phoenix/PullToRefreshView.java b/Phoenix/src/main/java/com/yalantis/phoenix/PullToRefreshView.java
index 14d5545..4d33313 100644
--- a/Phoenix/src/main/java/com/yalantis/phoenix/PullToRefreshView.java
+++ b/Phoenix/src/main/java/com/yalantis/phoenix/PullToRefreshView.java
@@ -418,7 +418,7 @@ private void setRefreshing(boolean refreshing, final boolean notify) {
         }
     }
 
-    private Animation.AnimationListener mToStartListener = new Animation.AnimationListener() {
+    private final Animation.AnimationListener mToStartListener = new Animation.AnimationListener() {
         @Override
         public void onAnimationStart(Animation animation) {
         }
diff --git a/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/BaseRefreshView.java b/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/BaseRefreshView.java
index 5b0ea29..3469f00 100644
--- a/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/BaseRefreshView.java
+++ b/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/BaseRefreshView.java
@@ -11,7 +11,7 @@
 
 public abstract class BaseRefreshView extends Drawable implements Drawable.Callback, Animatable {
 
-    private PullToRefreshView mRefreshLayout;
+    private final PullToRefreshView mRefreshLayout;
     private boolean mEndOfRefreshing;
 
     public BaseRefreshView(Context context, PullToRefreshView layout) {
diff --git a/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/SunRefreshView.java b/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/SunRefreshView.java
index 74e20c2..e523588 100644
--- a/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/SunRefreshView.java
+++ b/Phoenix/src/main/java/com/yalantis/phoenix/refresh_view/SunRefreshView.java
@@ -38,8 +38,8 @@ public class SunRefreshView extends BaseRefreshView implements Animatable {
 
     private static final Interpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
 
-    private PullToRefreshView mParent;
-    private Matrix mMatrix;
+    private final PullToRefreshView mParent;
+    private final Matrix mMatrix;
     private Animation mAnimation;
 
     private int mTop;
@@ -54,7 +54,7 @@ public class SunRefreshView extends BaseRefreshView implements Animatable {
     private float mTownFinalTopOffset;
     private float mTownMoveOffset;
 
-    private int mSunSize = 100;
+    private final int mSunSize = 100;
     private float mSunLeftOffset;
     private float mSunTopOffset;
 
diff --git a/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/PullToRefreshLayoutTellH/PullToRefreshLayout.java b/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/PullToRefreshLayoutTellH/PullToRefreshLayout.java
index eacfccd..671f5d7 100644
--- a/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/PullToRefreshLayoutTellH/PullToRefreshLayout.java
+++ b/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/PullToRefreshLayoutTellH/PullToRefreshLayout.java
@@ -435,7 +435,7 @@ public void run() {
         }
     }
 
-    private Animation.AnimationListener mToStartListener = new Animation.AnimationListener() {
+    private final Animation.AnimationListener mToStartListener = new Animation.AnimationListener() {
         @Override
         public void onAnimationStart(Animation animation) {
         }
@@ -450,7 +450,7 @@ public void onAnimationEnd(Animation animation) {
         }
     };
 
-    private Animation.AnimationListener mReadyToRefreshListener= new Animation.AnimationListener() {
+    private final Animation.AnimationListener mReadyToRefreshListener= new Animation.AnimationListener() {
         @Override
         public void onAnimationStart(Animation animation) {
 
diff --git a/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/WaterDropListView/WaterDropListView.java b/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/WaterDropListView/WaterDropListView.java
index 87df9da..73d0c9e 100644
--- a/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/WaterDropListView/WaterDropListView.java
+++ b/app/src/main/java/com/tellh/android_pulltorefreshlibrary_collection/WaterDropListView/WaterDropListView.java
@@ -33,7 +33,7 @@ public class WaterDropListView extends ListView implements OnScrollListener,Wate
 	// header view content, use it to calculate the Header's height. And hide it
 	// when disable pull refresh.
 //	private RelativeLayout mHeaderViewContent;
-	private boolean mEnablePullRefresh = true;
+	private final boolean mEnablePullRefresh = true;
 //	private boolean mPullRefreshing = false; // is refreashing.
 
 	// -- footer view
diff --git a/circlerefreshlayout/src/main/java/com/tuesda/walker/circlerefresh/CircleRefreshLayout.java b/circlerefreshlayout/src/main/java/com/tuesda/walker/circlerefresh/CircleRefreshLayout.java
index 17c7964..862af6a 100644
--- a/circlerefreshlayout/src/main/java/com/tuesda/walker/circlerefresh/CircleRefreshLayout.java
+++ b/circlerefreshlayout/src/main/java/com/tuesda/walker/circlerefresh/CircleRefreshLayout.java
@@ -63,7 +63,7 @@ public class CircleRefreshLayout extends FrameLayout {
     private ValueAnimator mUpBackAnimator;
     private ValueAnimator mUpTopAnimator;
 
-    private DecelerateInterpolator decelerateInterpolator = new DecelerateInterpolator(10);
+    private final DecelerateInterpolator decelerateInterpolator = new DecelerateInterpolator(10);
 
     public CircleRefreshLayout(Context context) {
         this(context, null, 0);
diff --git a/swipetorefreshlayoutgoogle/src/main/java/com/tellh/swipetorefreshlayoutgoogle/CircleImageView.java b/swipetorefreshlayoutgoogle/src/main/java/com/tellh/swipetorefreshlayoutgoogle/CircleImageView.java
index 9512385..f4c2612 100644
--- a/swipetorefreshlayoutgoogle/src/main/java/com/tellh/swipetorefreshlayoutgoogle/CircleImageView.java
+++ b/swipetorefreshlayoutgoogle/src/main/java/com/tellh/swipetorefreshlayoutgoogle/CircleImageView.java
@@ -125,9 +125,9 @@ public void setBackgroundColor(int color) {
     }
 
     private class OvalShadow extends OvalShape {
-        private RadialGradient mRadialGradient;
-        private Paint mShadowPaint;
-        private int mCircleDiameter;
+        private final RadialGradient mRadialGradient;
+        private final Paint mShadowPaint;
+        private final int mCircleDiameter;
 
         public OvalShadow(int shadowRadius, int circleDiameter) {
             super();
diff --git a/taurus_flyplane/src/main/java/com/yalantis/taurus/RefreshView.java b/taurus_flyplane/src/main/java/com/yalantis/taurus/RefreshView.java
index fd18f35..9edff22 100644
--- a/taurus_flyplane/src/main/java/com/yalantis/taurus/RefreshView.java
+++ b/taurus_flyplane/src/main/java/com/yalantis/taurus/RefreshView.java
@@ -51,10 +51,10 @@ public class RefreshView extends Drawable implements Drawable.Callback, Animatab
     private static final int MAX_WIND_X_OFFSET = 2000;
     private static final int RANDOM_Y_COEFFICIENT = 5;
 
-    private Context mContext;
-    private PullToRefreshView mParent;
-    private Matrix mMatrix;
-    private Matrix mAdditionalMatrix;
+    private final Context mContext;
+    private final PullToRefreshView mParent;
+    private final Matrix mMatrix;
+    private final Matrix mAdditionalMatrix;
     private Animation mAnimation;
 
     private int mTop;
@@ -62,8 +62,8 @@ public class RefreshView extends Drawable implements Drawable.Callback, Animatab
     private boolean mInverseDirection;
 
     //KEY: Y position, Value: X offset of wind
-    private Map<Float, Float> mWinds;
-    private Paint mWindPaint;
+    private final Map<Float, Float> mWinds;
+    private final Paint mWindPaint;
     private float mWindLineWidth;
     private boolean mNewWindSet;
 
@@ -88,7 +88,7 @@ public class RefreshView extends Drawable implements Drawable.Callback, Animatab
     private float mLoadingAnimationTime;
     private float mLastAnimationTime;
 
-    private Random mRandom;
+    private final Random mRandom;
     private boolean mEndOfRefreshing;
 
     private enum AnimationPart {