rewrote some streams and optionals

Mage.Sets/src/mage/cards/a/Abeyance.java

@@ -41,6 +41,7 @@ import mage.game.Game;
 import mage.game.events.GameEvent;
 import mage.target.TargetPlayer;
 
+import java.util.Optional;
 import java.util.UUID;
 
 /**
@@ -110,8 +111,8 @@ class AbeyanceEffect extends ContinuousRuleModifyingEffectImpl {
                 }
             }
             if (event.getType() == GameEvent.EventType.ACTIVATE_ABILITY) {
-                Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+                Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-                if (ability != null && !(ability instanceof ActivatedManaAbilityImpl)) {
+                if (ability.isPresent() && !(ability.get() instanceof ActivatedManaAbilityImpl)) {
                     return true;
                 }
             }

Mage.Sets/src/mage/cards/d/DampingMatrix.java

@@ -46,6 +46,7 @@ import mage.game.events.GameEvent;
 import mage.game.events.GameEvent.EventType;
 import mage.game.permanent.Permanent;
 
+import java.util.Optional;
 import java.util.UUID;
 
 /**
@@ -108,8 +109,8 @@ class DampingMatrixEffect extends ReplacementEffectImpl {
     public boolean applies(GameEvent event, Ability source, Game game) {
         MageObject object = game.getObject(event.getSourceId());
         if (object instanceof Permanent && filter.match((Permanent)object, game)) {
-            Ability ability = object.getAbilities().get(event.getTargetId());
+            Optional<Ability> ability = object.getAbilities().get(event.getTargetId());
-            if (ability != null && !(ability instanceof ActivatedManaAbilityImpl)) {
+            if (ability.isPresent() && !(ability.get() instanceof ActivatedManaAbilityImpl)) {
                 return true;
             }
         }

Mage.Sets/src/mage/cards/f/FaithsFetters.java

@@ -44,10 +44,10 @@ import mage.game.events.GameEvent;
 import mage.game.permanent.Permanent;
 import mage.target.TargetPermanent;
 
+import java.util.Optional;
 import java.util.UUID;
 
 /**
- *
  * @author LevelX2
  */
 public class FaithsFetters extends CardImpl {
@@ -114,12 +114,11 @@ class FaithsFettersEffect extends ContinuousRuleModifyingEffectImpl {
     public boolean applies(GameEvent event, Ability source, Game game) {
         Permanent enchantment = game.getPermanent(source.getSourceId());
         if (enchantment != null && enchantment.getAttachedTo().equals(event.getSourceId())) {
-            Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+            Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-            if (ability != null) {
+            if (ability.isPresent() && ability.get().getAbilityType() != AbilityType.MANA) {
-                if (ability.getAbilityType() != AbilityType.MANA) {
                 return true;
             }
-            }
+
         }
         return false;
     }

Mage.Sets/src/mage/cards/h/HandToHand.java

@@ -27,7 +27,6 @@
  */
 package mage.cards.h;
 
-import java.util.UUID;
 import mage.MageObject;
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleStaticAbility;
@@ -35,14 +34,13 @@ import mage.abilities.effects.ContinuousRuleModifyingEffectImpl;
 import mage.abilities.mana.ActivatedManaAbilityImpl;
 import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
-import mage.constants.CardType;
+import mage.constants.*;
-import mage.constants.Duration;
-import mage.constants.Outcome;
-import mage.constants.TurnPhase;
-import mage.constants.Zone;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 
+import java.util.Optional;
+import java.util.UUID;
+
 /**
  *
  * @author fireshoes
@@ -106,8 +104,8 @@ class HandToHandEffect extends ContinuousRuleModifyingEffectImpl {
                 }
             }
             if (event.getType() == GameEvent.EventType.ACTIVATE_ABILITY) {
-                Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+                Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-                if (ability != null && !(ability instanceof ActivatedManaAbilityImpl)) {
+                if (ability.isPresent() && !(ability.get() instanceof ActivatedManaAbilityImpl)) {
                     return true;
                 }
             }

Mage.Sets/src/mage/cards/m/MoltenDisaster.java

@@ -27,7 +27,6 @@
  */
 package mage.cards.m;
 
-import java.util.UUID;
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleStaticAbility;
 import mage.abilities.condition.common.KickedCondition;
@@ -50,6 +49,9 @@ import mage.game.events.GameEvent;
 import mage.game.permanent.Permanent;
 import mage.players.Player;
 
+import java.util.Optional;
+import java.util.UUID;
+
 /**
  *
  * @author LevelX2
@@ -109,8 +111,8 @@ class MoltenDisasterSplitSecondEffect extends ContinuousRuleModifyingEffectImpl
             }
         }
         if (event.getType() == GameEvent.EventType.ACTIVATE_ABILITY) {
-            Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+            Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-            if (ability != null && !(ability instanceof ActivatedManaAbilityImpl)) {
+            if (ability.isPresent() && !(ability.get() instanceof ActivatedManaAbilityImpl)) {
                 if (KickedCondition.instance.apply(game, source)) {
                     return true;
                 }

Mage.Sets/src/mage/cards/p/PithingNeedle.java

@@ -27,7 +27,6 @@
  */
 package mage.cards.p;
 
-import java.util.UUID;
 import mage.MageObject;
 import mage.abilities.Ability;
 import mage.abilities.common.AsEntersBattlefieldAbility;
@@ -36,14 +35,13 @@ import mage.abilities.effects.ContinuousRuleModifyingEffectImpl;
 import mage.abilities.effects.common.NameACardEffect;
 import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
-import mage.constants.AbilityType;
+import mage.constants.*;
-import mage.constants.CardType;
-import mage.constants.Duration;
-import mage.constants.Outcome;
-import mage.constants.Zone;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 
+import java.util.Optional;
+import java.util.UUID;
+
 /**
  *
  * @author jeffwadsworth, nox
@@ -99,9 +97,9 @@ class PithingNeedleEffect extends ContinuousRuleModifyingEffectImpl {
     @Override
     public boolean applies(GameEvent event, Ability source, Game game) {
         MageObject object = game.getObject(event.getSourceId());
-        Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+        Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-        if (ability != null && object != null) {
+        if (ability.isPresent() && object != null) {
-            if (ability.getAbilityType() != AbilityType.MANA
+            if (ability.get().getAbilityType() != AbilityType.MANA
                     && object.getName().equals(game.getState().getValue(source.getSourceId().toString() + NameACardEffect.INFO_KEY))) {
                 return true;
             }

Mage.Tests/src/test/java/org/mage/test/cards/watchers/KiraGreatGlassSpinnerTest.java

@@ -0,0 +1,37 @@
+package org.mage.test.cards.watchers;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import mage.game.permanent.Permanent;
+import org.junit.Assert;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * Created by IGOUDT on 30-3-2017.
+ */
+public class KiraGreatGlassSpinnerTest extends CardTestPlayerBase {
+    private final String kira = "Kira, Great Glass-Spinner";
+    private final String shock = "Shock";
+
+    @Test
+    public void counterFirst(){
+        addCard(Zone.BATTLEFIELD, playerA, "Mountain", 4);
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 4);
+        addCard(Zone.BATTLEFIELD, playerA, "Ugin, the Spirit Dragon"); // starts with 7 Loyality counters
+
+        addCard(Zone.BATTLEFIELD, playerA, kira);
+        addCard(Zone.HAND, playerA, shock);
+        addCard(Zone.HAND, playerA, shock);
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "+2: {source} deals 3 damage to target creature or player.", kira);
+
+        setStopAt(1, PhaseStep.BEGIN_COMBAT);
+
+        execute();
+
+        Permanent _kira = getPermanent(kira, playerA.getId());
+        Assert.assertNotNull(_kira);
+
+
+    }
+}

Mage/src/main/java/mage/abilities/Abilities.java

@@ -29,6 +29,7 @@ package mage.abilities;
 
 import java.io.Serializable;
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 import mage.abilities.keyword.ProtectionAbility;
 import mage.abilities.mana.ActivatedManaAbilityImpl;
@@ -245,7 +246,7 @@ public interface Abilities<T extends Ability> extends List<T>, Serializable {
      * @param abilityId
      * @return
      */
-    T get(UUID abilityId);
+    Optional<T> get(UUID abilityId);
 
     /**
      * TODO The usage of this method seems redundant to that of

Mage/src/main/java/mage/abilities/AbilitiesImpl.java

@@ -27,13 +27,6 @@
  */
 package mage.abilities;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
-import java.util.UUID;
-
 import mage.abilities.common.ZoneChangeTriggeredAbility;
 import mage.abilities.costs.Cost;
 import mage.abilities.keyword.ProtectionAbility;
@@ -44,6 +37,8 @@ import mage.game.Game;
 import mage.util.ThreadLocalStringBuilder;
 import org.apache.log4j.Logger;
 
+import java.util.*;
+
 /**
  * @param <T>
  * @author BetaSteward_at_googlemail.com
@@ -277,12 +272,7 @@ public class AbilitiesImpl<T extends Ability> extends ArrayList<T> implements Ab
 
     @Override
     public boolean containsRule(T ability) {
-        for (T test : this) {
+        return stream().anyMatch(rule -> rule.getRule().equals(ability.getRule()));
-            if (ability.getRule().equals(test.getRule())) {
-                return true;
-            }
-        }
-        return false;
     }
 
     @Override
@@ -301,32 +291,16 @@ public class AbilitiesImpl<T extends Ability> extends ArrayList<T> implements Ab
 
     @Override
     public boolean containsKey(UUID abilityId) {
-        for (T ability : this) {
+        return stream().anyMatch(ability -> ability.getId().equals(abilityId));
-            if (ability.getId().equals(abilityId)) {
-                return true;
-            }
-        }
-        return false;
     }
 
     @Override
     public boolean containsClass(Class classObject) {
-        for (T ability : this) {
+        return stream().anyMatch(ability -> ability.getClass().equals(classObject));
-            if (ability.getClass().equals(classObject)) {
-                return true;
-            }
-        }
-        return false;
     }
 
-    @Override
+    public Optional<T> get(UUID abilityId) {
-    public T get(UUID abilityId) {
+        return stream().filter(ability -> ability.getId().equals(abilityId)).findFirst();
-        for (T ability : this) {
-            if (ability.getId().equals(abilityId)) {
-                return ability;
-            }
-        }
-        return null;
     }
 
     @Override

Mage/src/main/java/mage/abilities/Ability.java

@@ -27,9 +27,6 @@
  */
 package mage.abilities;
 
-import java.io.Serializable;
-import java.util.List;
-import java.util.UUID;
 import mage.MageObject;
 import mage.abilities.costs.Cost;
 import mage.abilities.costs.Costs;
@@ -49,6 +46,11 @@ import mage.target.Target;
 import mage.target.Targets;
 import mage.watchers.Watcher;
 
+import java.io.Serializable;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
 /**
  * Practically everything in the game is started from an Ability. This interface
  * describes what an Ability is composed of at the highest level.

Mage/src/main/java/mage/abilities/DelayedTriggeredAbilities.java

@@ -28,18 +28,19 @@
 
 package mage.abilities;
 
-import java.util.Iterator;
 import mage.constants.Duration;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 
+import java.util.Iterator;
+
 /**
- *
  * @author BetaSteward_at_googlemail.com
  */
 public class DelayedTriggeredAbilities extends AbilitiesImpl<DelayedTriggeredAbility> {
 
-     public DelayedTriggeredAbilities() {}
+    public DelayedTriggeredAbilities() {
+    }
 
     public DelayedTriggeredAbilities(final DelayedTriggeredAbilities abilities) {
         super(abilities);

Mage/src/main/java/mage/abilities/keyword/SplitSecondAbility.java

@@ -10,6 +10,8 @@ import mage.constants.Zone;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 
+import java.util.Optional;
+
 /**
  * Split Second
  *
@@ -66,8 +68,8 @@ class SplitSecondEffect extends ContinuousRuleModifyingEffectImpl {
             return true;
         }
         if (event.getType() == GameEvent.EventType.ACTIVATE_ABILITY) {
-            Ability ability = game.getAbility(event.getTargetId(), event.getSourceId());
+            Optional<Ability> ability = game.getAbility(event.getTargetId(), event.getSourceId());
-            if (ability != null && !(ability instanceof ActivatedManaAbilityImpl)) {
+            if (ability != null && !(ability.get() instanceof ActivatedManaAbilityImpl)) {
                 return true;
             }
         }

Mage/src/main/java/mage/cards/CardsImpl.java

@@ -34,6 +34,7 @@ import mage.util.ThreadLocalStringBuilder;
 
 import java.io.Serializable;
 import java.util.*;
+import java.util.stream.Collectors;
 
 /**
  * @author BetaSteward_at_googlemail.com
@@ -109,13 +110,7 @@ public class CardsImpl extends LinkedHashSet<UUID> implements Cards, Serializabl
 
     @Override
     public int count(FilterCard filter, Game game) {
-        int result = 0;
+        return (int) stream().filter(cardId -> filter.match(game.getCard(cardId), game)).count();
-        for (UUID cardId : this) {
-            if (filter.match(game.getCard(cardId), game)) {
-                result++;
-            }
-        }
-        return result;
     }
 
     @Override
@@ -150,14 +145,7 @@ public class CardsImpl extends LinkedHashSet<UUID> implements Cards, Serializabl
 
     @Override
     public Set<Card> getCards(FilterCard filter, Game game) {
-        Set<Card> cards = new LinkedHashSet<>();
+        return stream().map(game::getCard).filter(card -> filter.match(card, game)).collect(Collectors.toSet());
-        for (UUID card : this) {
-            boolean match = filter.match(game.getCard(card), game);
-            if (match) {
-                cards.add(game.getCard(card));
-            }
-        }
-        return cards;
     }
 
     @Override

Mage/src/main/java/mage/cards/ExpansionSet.java

@@ -36,6 +36,7 @@ import mage.util.RandomUtil;
 
 import java.io.Serializable;
 import java.util.*;
+import java.util.stream.Collectors;
 
 /**
  * @author BetaSteward_at_googlemail.com
@@ -160,13 +161,7 @@ public abstract class ExpansionSet implements Serializable {
     }
 
     public List<SetCardInfo> findCardInfoByClass(Class<?> clazz) {
-        ArrayList<SetCardInfo> result = new ArrayList<>();
+        return cards.stream().filter(info -> info.getCardClass().equals(clazz)).collect(Collectors.toList());
-        for (SetCardInfo info : cards) {
-            if (info.getCardClass().equals(clazz)) {
-                result.add(info);
-            }
-        }
-        return result;
     }
 
     public List<Card> create15CardBooster() {

Mage/src/main/java/mage/counters/Counters.java

@@ -28,10 +28,10 @@
 package mage.counters;
 
 import java.io.Serializable;
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 /**
  * @author BetaSteward_at_googlemail.com
@@ -122,12 +122,9 @@ public class Counters extends HashMap<String, Counter> implements Serializable {
     }
 
     public List<BoostCounter> getBoostCounters() {
-        List<BoostCounter> boosters = new ArrayList<>();
+        return values().stream().
-        for (Counter counter : this.values()) {
+                filter(counter -> counter instanceof BoostCounter).
-            if (counter instanceof BoostCounter) {
+                map(counter -> (BoostCounter) counter).
-                boosters.add((BoostCounter) counter);
+                collect(Collectors.toList());
-            }
-        }
-        return boosters;
     }
 }

Mage/src/main/java/mage/game/Game.java

@@ -27,14 +27,6 @@
  */
 package mage.game;
 
-import java.io.Serializable;
-import java.util.Collection;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
 import mage.MageItem;
 import mage.MageObject;
 import mage.abilities.Ability;
@@ -50,11 +42,7 @@ import mage.cards.Cards;
 import mage.cards.MeldCard;
 import mage.cards.decks.Deck;
 import mage.choices.Choice;
-import mage.constants.Duration;
+import mage.constants.*;
-import mage.constants.MultiplayerAttackOption;
-import mage.constants.PlayerAction;
-import mage.constants.RangeOfInfluence;
-import mage.constants.Zone;
 import mage.counters.Counters;
 import mage.game.combat.Combat;
 import mage.game.command.Commander;
@@ -77,6 +65,9 @@ import mage.players.Players;
 import mage.util.MessageToClient;
 import mage.util.functions.ApplyToPermanent;
 
+import java.io.Serializable;
+import java.util.*;
+
 public interface Game extends MageItem, Serializable {
 
     MatchType getGameType();
@@ -128,7 +119,7 @@ public interface Game extends MageItem, Serializable {
 
     Card getCard(UUID cardId);
 
-    Ability getAbility(UUID abilityId, UUID sourceId);
+    Optional<Ability> getAbility(UUID abilityId, UUID sourceId);
 
     void setZone(UUID objectId, Zone zone);
 

Mage/src/main/java/mage/game/GameImpl.java

@@ -503,12 +503,12 @@ public abstract class GameImpl implements Game, Serializable {
     }
 
     @Override
-    public Ability getAbility(UUID abilityId, UUID sourceId) {
+    public Optional<Ability> getAbility(UUID abilityId, UUID sourceId) {
         MageObject object = getObject(sourceId);
         if (object != null) {
             return object.getAbilities().get(abilityId);
         }
-        return null;
+        return Optional.empty();
     }
 
 //    @Override
@@ -2336,10 +2336,10 @@ public abstract class GameImpl implements Game, Serializable {
             }
         }
 
-        Iterator it = gameCards.entrySet().iterator();
+        Iterator<Entry<UUID, Card>> it = gameCards.entrySet().iterator();
 
         while (it.hasNext()) {
-            Entry<UUID, Card> entry = (Entry<UUID, Card>) it.next();
+            Entry<UUID, Card> entry = it.next();
             Card card = entry.getValue();
             if (card.getOwnerId().equals(playerId)) {
                 it.remove();

Mage/src/main/java/mage/game/command/Commander.java

@@ -27,10 +27,6 @@
  */
 package mage.game.command;
 
-import java.util.EnumSet;
-import java.util.List;
-import java.util.Set;
-import java.util.UUID;
 import mage.MageInt;
 import mage.ObjectColor;
 import mage.abilities.Abilities;
@@ -48,18 +44,22 @@ import mage.game.Game;
 import mage.game.events.ZoneChangeEvent;
 import mage.util.GameLog;
 
+import java.util.EnumSet;
+import java.util.List;
+import java.util.UUID;
+
 public class Commander implements CommandObject {
 
     private final Card sourceObject;
-    private final Abilities<Ability> abilites = new AbilitiesImpl<>();
+    private final Abilities<Ability> abilities = new AbilitiesImpl<>();
 
     public Commander(Card card) {
         this.sourceObject = card;
-        abilites.add(new CastCommanderAbility(card));
+        abilities.add(new CastCommanderAbility(card));
         for (Ability ability : card.getAbilities()) {
             if (!(ability instanceof SpellAbility)) {
                 Ability newAbility = ability.copy();
-                abilites.add(newAbility);
+                abilities.add(newAbility);
             }
         }
     }
@@ -134,7 +134,7 @@ public class Commander implements CommandObject {
 
     @Override
     public Abilities<Ability> getAbilities() {
-        return abilites;
+        return abilities;
     }
 
     @Override

Mage/src/main/java/mage/game/command/Emblem.java

@@ -27,8 +27,6 @@
  */
 package mage.game.command;
 
-import java.util.*;
-
 import mage.MageInt;
 import mage.MageObject;
 import mage.ObjectColor;
@@ -46,6 +44,11 @@ import mage.game.Game;
 import mage.game.events.ZoneChangeEvent;
 import mage.util.GameLog;
 
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.UUID;
+
 /**
  * @author nantuko
  */
@@ -92,7 +95,7 @@ public class Emblem implements CommandObject {
         this.sourceObject = sourceObject;
         if (sourceObject instanceof Card) {
             if (name.isEmpty()) {
-                name = ((Card) sourceObject).getSubtype(null).toString();
+                name = sourceObject.getSubtype(null).toString();
             }
             if (expansionSetCodeForImage.isEmpty()) {
                 expansionSetCodeForImage = ((Card) sourceObject).getExpansionSetCode();

Mage/src/main/java/mage/game/permanent/Battlefield.java

@@ -103,22 +103,20 @@ public class Battlefield implements Serializable {
      * @return count
      */
     public int count(FilterPermanent filter, UUID sourceId, UUID sourcePlayerId, Game game) {
-        int count;
         if (game.getRangeOfInfluence() == RangeOfInfluence.ALL) {
-            count = (int) field.values()
+            return (int) field.values()
                     .stream()
                     .filter(permanent -> filter.match(permanent, sourceId, sourcePlayerId, game)
                             && permanent.isPhasedIn())
                     .count();
         } else {
             Set<UUID> range = game.getPlayer(sourcePlayerId).getInRange();
-            count = (int) field.values()
+            return  (int) field.values()
                     .stream()
                     .filter(permanent -> range.contains(permanent.getControllerId())
                             && filter.match(permanent, sourceId, sourcePlayerId, game)
                             && permanent.isPhasedIn()).count();
         }
-        return count;
     }
 
     /**
@@ -319,20 +317,18 @@ public class Battlefield implements Serializable {
      * @see Permanent
      */
     public List<Permanent> getActivePermanents(FilterPermanent filter, UUID sourcePlayerId, UUID sourceId, Game game) {
-        List<Permanent> active = new ArrayList<>();
         if (game.getRangeOfInfluence() == RangeOfInfluence.ALL) {
-            active = field.values()
+            return field.values()
                     .stream()
                     .filter(perm -> perm.isPhasedIn() && filter.match(perm, sourceId, sourcePlayerId, game))
                     .collect(Collectors.toList());
         } else {
             Set<UUID> range = game.getPlayer(sourcePlayerId).getInRange();
-            active = field.values()
+            return  field.values()
                     .stream()
                     .filter(perm -> perm.isPhasedIn() && range.contains(perm.getControllerId())
                             && filter.match(perm, sourceId, sourcePlayerId, game)).collect(Collectors.toList());
         }
-        return active;
     }
 
     /**

Mage/src/main/java/mage/game/stack/Spell.java

@@ -27,8 +27,6 @@
  */
 package mage.game.stack;
 
-import java.util.*;
-
 import mage.MageInt;
 import mage.MageObject;
 import mage.Mana;
@@ -60,6 +58,11 @@ import mage.game.permanent.PermanentCard;
 import mage.players.Player;
 import mage.util.GameLog;
 
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.UUID;
+
 /**
  *
  * @author BetaSteward_at_googlemail.com
@@ -331,8 +334,8 @@ public class Spell extends StackObjImpl implements Card {
      * determine whether card was kicked or not. E.g. Desolation Angel
      */
     private void updateOptionalCosts(int index) {
-        Ability abilityOrig = spellCards.get(index).getAbilities().get(spellAbilities.get(index).getId());
+        spellCards.get(index).getAbilities().get(spellAbilities.get(index).getId()).ifPresent(abilityOrig ->
-        if (abilityOrig != null) {
+        {
             for (Object object : spellAbilities.get(index).getOptionalCosts()) {
                 Cost cost = (Cost) object;
                 for (Cost costOrig : abilityOrig.getOptionalCosts()) {
@@ -346,7 +349,7 @@ public class Spell extends StackObjImpl implements Card {
                     }
                 }
             }
-        }
+        });
     }
 
     @Override

Mage/src/main/java/mage/players/Library.java

@@ -27,26 +27,16 @@
  */
 package mage.players;
 
-import java.io.Serializable;
-import java.util.ArrayDeque;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Deque;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
 import mage.cards.Card;
 import mage.constants.Zone;
 import mage.filter.FilterCard;
 import mage.game.Game;
 import mage.util.RandomUtil;
 
+import java.io.Serializable;
+import java.util.*;
+import java.util.stream.Collectors;
+
 /**
  * @author BetaSteward_at_googlemail.com
  */
@@ -182,11 +172,7 @@ public class Library implements Serializable {
     }
 
     public List<Card> getCards(Game game) {
-        List<Card> cards = new ArrayList<>();
+        return library.stream().map(game::getCard).collect(Collectors.toList());
-        for (UUID cardId : library) {
-            cards.add(game.getCard(cardId));
-        }
-        return cards;
     }
 
     public Set<Card> getTopCards(Game game, int amount) {
@@ -214,13 +200,7 @@ public class Library implements Serializable {
     }
 
     public int count(FilterCard filter, Game game) {
-        int result = 0;
+        return (int) library.stream().filter(cardId -> filter.match(game.getCard(cardId), game)).count();
-        for (UUID card : library) {
-            if (filter.match(game.getCard(card), game)) {
-                result++;
-            }
-        }
-        return result;
     }
 
     public boolean isEmptyDraw() {

Mage/src/main/java/mage/target/TargetAmount.java

@@ -34,6 +34,7 @@ import mage.abilities.dynamicvalue.common.StaticValue;
 import mage.constants.Outcome;
 import mage.game.Game;
 import java.util.*;
+import java.util.stream.Collectors;
 
 /**
  *
@@ -142,12 +143,7 @@ public abstract class TargetAmount extends TargetImpl {
                 t.addTarget(targetId, n, source, game, true);
                 if (t.remainingAmount > 0) {
                     if (targets.size() > 1) {
-                        Set<UUID> newTargets = new HashSet<>();
+                        Set<UUID> newTargets = targets.stream().filter(newTarget -> !newTarget.equals(targetId)).collect(Collectors.toSet());
-                        for (UUID newTarget: targets) {
-                            if (!newTarget.equals(targetId)) {
-                                newTargets.add(newTarget);
-                            }
-                        }
                         addTargets(t, newTargets, options, source, game);
                     }
                 }

Mage/src/main/java/mage/target/TargetCard.java

@@ -27,9 +27,7 @@
  */
 package mage.target;
 
-import java.util.HashSet;
+import mage.MageItem;
-import java.util.Set;
-import java.util.UUID;
 import mage.cards.Card;
 import mage.cards.Cards;
 import mage.constants.Zone;
@@ -38,6 +36,11 @@ import mage.game.Game;
 import mage.game.events.GameEvent;
 import mage.players.Player;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
 /**
  *
  * @author BetaSteward_at_googlemail.com
@@ -200,11 +203,7 @@ public class TargetCard extends TargetObject {
     }
 
     public Set<UUID> possibleTargets(UUID sourceControllerId, Cards cards, Game game) {
-        Set<UUID> possibleTargets = new HashSet<>();
+        return cards.getCards(filter,game).stream().map(MageItem::getId).collect(Collectors.toSet());
-        for (Card card : cards.getCards(filter, game)) {
-            possibleTargets.add(card.getId());
-        }
-        return possibleTargets;
     }
 
     @Override

Mage/src/main/java/mage/target/TargetPlayer.java

@@ -27,15 +27,16 @@
  */
 package mage.target;
 
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
 import mage.MageObject;
 import mage.abilities.Ability;
 import mage.filter.FilterPlayer;
 import mage.game.Game;
 import mage.players.Player;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
 /**
  *
  * @author BetaSteward_at_googlemail.com
@@ -158,12 +159,7 @@ public class TargetPlayer extends TargetImpl {
         if (getNumberOfTargets() == 0 && targets.isEmpty()) {
             return true; // 0 targets selected is valid
         }
-        for (UUID playerId : targets.keySet()) {
+        return targets.keySet().stream().anyMatch(playerId -> canTarget(playerId, source, game));
-            if (canTarget(playerId, source, game)) {
-                return true;
-            }
-        }
-        return false;
     }
 
     @Override

Mage/src/main/java/mage/target/TargetSpell.java

@@ -27,9 +27,6 @@
  */
 package mage.target;
 
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
 import mage.abilities.Ability;
 import mage.constants.Zone;
 import mage.filter.FilterSpell;
@@ -37,6 +34,11 @@ import mage.game.Game;
 import mage.game.stack.Spell;
 import mage.game.stack.StackObject;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
 /**
  *
  * @author BetaSteward_at_googlemail.com
@@ -112,13 +114,10 @@ public class TargetSpell extends TargetObject {
 
     @Override
     public Set<UUID> possibleTargets(UUID sourceId, UUID sourceControllerId, Game game) {
-        Set<UUID> possibleTargets = new HashSet<>();
+        return game.getStack().stream()
-        for (StackObject stackObject : game.getStack()) {
+                .filter(stackObject -> canBeChosen(stackObject, sourceId, sourceControllerId, game))
-            if (canBeChosen(stackObject, sourceId, sourceControllerId, game)) {
+                .map(StackObject::getId)
-                possibleTargets.add(stackObject.getId());
+                .collect(Collectors.toSet());
-            }
-        }
-        return possibleTargets;
     }
 
     @Override

Mage/src/main/java/mage/target/Targets.java

@@ -27,14 +27,16 @@
  */
 package mage.target;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.UUID;
 import mage.abilities.Ability;
 import mage.constants.Outcome;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
 /**
  *
  * @author BetaSteward_at_googlemail.com
@@ -51,13 +53,7 @@ public class Targets extends ArrayList<Target> {
     }
 
     public List<Target> getUnchosen() {
-        List<Target> unchosen = new ArrayList<>();
+        return stream().filter(target -> !target.isChosen()).collect(Collectors.toList());
-        for (Target target : this) {
-            if (!target.isChosen()) {
-                unchosen.add(target);
-            }
-        }
-        return unchosen;
     }
 
     public void clearChosen() {
@@ -67,12 +63,7 @@ public class Targets extends ArrayList<Target> {
     }
 
     public boolean isChosen() {
-        for (Target target : this) {
+        return stream().allMatch(Target::isChosen);
-            if (!target.isChosen()) {
-                return false;
-            }
-        }
-        return true;
     }
 
     public boolean choose(Outcome outcome, UUID playerId, UUID sourceId, Game game) {
@@ -122,12 +113,8 @@ public class Targets extends ArrayList<Target> {
     public boolean stillLegal(Ability source, Game game) {
         // 608.2
         // The spell or ability is countered if all its targets, for every instance of the word "target," are now illegal
-        int illegalCount = 0;
+        int illegalCount = (int) stream().filter(target -> !target.isLegal(source, game)).count();
-        for (Target target : this) {
+
-            if (!target.isLegal(source, game)) {
-                illegalCount++;
-            }
-        }
         // it is legal when either there is no target or not all targets are illegal
         return this.isEmpty() || this.size() != illegalCount;
     }
@@ -142,12 +129,7 @@ public class Targets extends ArrayList<Target> {
      * @return - true if enough valid targets exist
      */
     public boolean canChoose(UUID sourceId, UUID sourceControllerId, Game game) {
-        for (Target target : this) {
+        return stream().allMatch(target -> target.canChoose(sourceId, sourceControllerId, game));
-            if (!target.canChoose(sourceId, sourceControllerId, game)) {
-                return false;
-            }
-        }
-        return true;
     }
 
     /**
@@ -160,12 +142,7 @@ public class Targets extends ArrayList<Target> {
      * @return - true if enough valid objects exist
      */
     public boolean canChoose(UUID sourceControllerId, Game game) {
-        for (Target target : this) {
+        return stream().allMatch(target -> target.canChoose(sourceControllerId, game));
-            if (!target.canChoose(sourceControllerId, game)) {
-                return false;
-            }
-        }
-        return true;
     }
 
     public UUID getFirstTarget() {
@@ -174,7 +151,6 @@ public class Targets extends ArrayList<Target> {
         }
         return null;
     }
-
     public Targets copy() {
         return new Targets(this);
     }

Mage/src/main/java/mage/target/common/TargetActivatedOrTriggeredAbility.java

@@ -28,20 +28,20 @@
 
 package mage.target.common;
 
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
-import mage.constants.Zone;
 import mage.abilities.Ability;
 import mage.constants.AbilityType;
+import mage.constants.Zone;
 import mage.filter.Filter;
 import mage.filter.FilterAbility;
 import mage.game.Game;
 import mage.game.stack.StackObject;
 import mage.target.TargetObject;
 
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
 /**
- *
  * @author LevelX2
  */
 
@@ -78,12 +78,9 @@ public class TargetActivatedOrTriggeredAbility extends TargetObject {
 
     @Override
     public boolean canChoose(UUID sourceControllerId, Game game) {
-        for (StackObject stackObject : game.getStack()) {
+        return game.getStack()
-            if (isActivatedOrTriggeredAbility(stackObject)) {
+                .stream()
-                return true;
+                .anyMatch(TargetActivatedOrTriggeredAbility::isActivatedOrTriggeredAbility);
-            }
-        }
-        return false;
     }
 
     @Override
@@ -93,13 +90,10 @@ public class TargetActivatedOrTriggeredAbility extends TargetObject {
 
     @Override
     public Set<UUID> possibleTargets(UUID sourceControllerId, Game game) {
-        Set<UUID> possibleTargets = new HashSet<>();
+        return game.getStack().stream()
-        for (StackObject stackObject :  game.getStack()) {
+                .filter(TargetActivatedOrTriggeredAbility::isActivatedOrTriggeredAbility)
-            if (isActivatedOrTriggeredAbility(stackObject)) {
+                .map(stackObject -> stackObject.getStackAbility().getId())
-                possibleTargets.add(stackObject.getStackAbility().getId());
+                .collect(Collectors.toSet());
-            }
-        }
-        return possibleTargets;
     }
 
     @Override

Mage/src/main/java/mage/target/common/TargetCardInGraveyardOrBattlefield.java

@@ -27,8 +27,6 @@
  */
 package mage.target.common;
 
-import java.util.Set;
-import java.util.UUID;
 import mage.MageObject;
 import mage.abilities.Ability;
 import mage.cards.Card;
@@ -39,8 +37,10 @@ import mage.game.Game;
 import mage.game.permanent.Permanent;
 import mage.target.TargetCard;
 
+import java.util.Set;
+import java.util.UUID;
+
 /**
- *
  * @author LevelX2
  */
 public class TargetCardInGraveyardOrBattlefield extends TargetCard {
@@ -82,8 +82,7 @@ public class TargetCardInGraveyardOrBattlefield extends TargetCard {
     }
 
     @Override
-    public boolean canTarget(UUID id, Ability source, Game game
+    public boolean canTarget(UUID id, Ability source, Game game) {
-    ) {
         Permanent permanent = game.getPermanent(id);
         if (permanent != null) {
             return filter.match(permanent, game);
@@ -93,8 +92,7 @@ public class TargetCardInGraveyardOrBattlefield extends TargetCard {
     }
 
     @Override
-    public Set<UUID> possibleTargets(UUID sourceControllerId, Game game
+    public Set<UUID> possibleTargets(UUID sourceControllerId, Game game) {
-    ) {
         //return super.possibleTargets(sourceControllerId, game); //To change body of generated methods, choose Tools | Templates.
         Set<UUID> possibleTargets = super.possibleTargets(sourceControllerId, game);
         for (Permanent permanent : game.getBattlefield().getActivePermanents(new FilterPermanent(), sourceControllerId, game)) {
@@ -106,8 +104,7 @@ public class TargetCardInGraveyardOrBattlefield extends TargetCard {
     }
 
     @Override
-    public Set<UUID> possibleTargets(UUID sourceId, UUID sourceControllerId, Game game
+    public Set<UUID> possibleTargets(UUID sourceId, UUID sourceControllerId, Game game) {
-    ) {
         Set<UUID> possibleTargets = super.possibleTargets(sourceId, sourceControllerId, game);
         MageObject targetSource = game.getObject(sourceId);
         for (Permanent permanent : game.getBattlefield().getActivePermanents(new FilterPermanent(), sourceControllerId, game)) {