Miscellaneous code analysis warning fixes

app/src/LightningPlus/java/acr/browser/lightning/utils/ProxyUtils.java

@@ -3,7 +3,6 @@ package acr.browser.lightning.utils;
 import android.app.Activity;
 import android.content.Context;
 import android.content.DialogInterface;
-import android.os.Build;
 import android.support.annotation.NonNull;
 import android.support.v7.app.AlertDialog;
 import android.util.Log;

app/src/main/java/acr/browser/lightning/activity/ThemableSettingsActivity.java

@@ -1,6 +1,5 @@
 package acr.browser.lightning.activity;
 
-import android.content.Intent;
 import android.graphics.drawable.ColorDrawable;
 import android.os.Bundle;
 

app/src/main/java/acr/browser/lightning/download/WebAddress.java

@@ -97,7 +97,7 @@ public class WebAddress {
         /*
          * Get port from scheme or scheme from port, if necessary and possible
          */
-        if (mPort == 443 && "".equals(mScheme)) {
+        if (mPort == 443 && mScheme != null && mScheme.isEmpty()) {
             mScheme = "https";
         } else if (mPort == -1) {
             if ("https".equals(mScheme)) {
@@ -106,7 +106,7 @@ public class WebAddress {
                 mPort = 80; // default
             }
         }
-        if ("".equals(mScheme)) {
+        if (mScheme != null && mScheme.isEmpty()) {
             mScheme = "http";
         }
     }

app/src/main/java/acr/browser/lightning/fragment/AdvancedSettingsFragment.java

@@ -11,7 +11,6 @@ import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.support.v7.app.AlertDialog;
 
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 

app/src/main/java/acr/browser/lightning/fragment/DisplaySettingsFragment.java

@@ -12,7 +12,6 @@ import android.preference.PreferenceFragment;
 import android.support.v7.app.AlertDialog;
 import android.view.Gravity;
 import android.view.LayoutInflater;
-import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowManager;
 import android.widget.LinearLayout;

app/src/main/java/acr/browser/lightning/reading/ArticleTextExtractor.java

@@ -238,7 +238,7 @@ public class ArticleTextExtractor {
             content = content.substring(1, content.length() - 1);
 
         String[] split = content.split("\\s*,\\s*");
-        if (split.length > 1 || (split.length > 0 && !"".equals(split[0])))
+        if (split.length > 1 || (split.length > 0 && split[0] != null && !split[0].isEmpty()))
             return Arrays.asList(split);
         return Collections.emptyList();
     }

app/src/main/java/acr/browser/lightning/reading/MapEntry.java

@@ -53,7 +53,7 @@ public class MapEntry<K, V> implements Map.Entry<K, V>, Serializable {
 
     @Override
     public String toString() {
-        return getKey() + ", " + getValue();
+        return key + ", " + value;
     }
 
     @Override

app/src/main/java/acr/browser/lightning/utils/ThemeUtils.java

@@ -1,7 +1,6 @@
 package acr.browser.lightning.utils;
 
 import android.content.Context;
-import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
@@ -10,7 +9,6 @@ import android.graphics.ColorFilter;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffColorFilter;
-import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.support.annotation.AttrRes;