[英]JAVA - Removing non iterator element from iterating list
我在遍歷這個迭代器循環時遇到了問題,我遍歷 this.env 的每個元素,但在這個列表中,想要刪除所述列表的不同元素。 當我嘗試刪除所述迭代列表的任何項目時,我收到此錯誤: java.util.ConcurrentModificationException ,據我所知,這是由於在不使用 iterator.remove() 的情況下修改迭代列表造成的。
代碼:
public void envActions(IOHandler ioHandler, PlayerClass player){
Iterator<WorldElement> worldElementIterator = this.env.iterator();
while(worldElementIterator.hasNext()){
WorldElement worldElement = worldElementIterator.next();
//for(WorldElement worldElement:this.env){
if(worldElement instanceof EntityClass){
EntityClass entity=(EntityClass) worldElement;
if(entity.nature.contains("hostile")){
MonsterClass mEntity=(MonsterClass) entity;
if(!(mEntity.attacks.size()*(Math.random()+0.25)>=mEntity.attacks.size())){
Double followerNum = (Math.random()*player.followers.size());
Integer followerNumInt=followerNum.intValue();
if(followerNumInt<2){
PlayerClass target=player;
Double attacknumD=mEntity.attacks.size()*Math.random();
Integer attacknum= attacknumD.intValue();
Integer playerarmor=player.getArmorValue();
int enemydamage=mEntity.attacks.get(attacknum).getDamage()*(1-(playerarmor/1000));
target.health=target.health-enemydamage;
ioHandler.printToConsole("\nThe "+mEntity.name+" attacked you with "+mEntity.attacks.get(attacknum).getAttack()+" and did "+mEntity.attacks.get(attacknum).getDamage()+" damage! you have "+player.health+" health left!");
} else {
FriendlyCreatureClass target=player.followers.get(followerNumInt);
Double attacknumD=mEntity.attacks.size()*Math.random();
Integer attacknum= attacknumD.intValue();
int enemydamage=mEntity.attacks.get(attacknum).getDamage();
target.health=target.health-enemydamage;
if(!target.isAlive()){
ioHandler.printToConsole("\nThe " + mEntity.name + " attacked " + target.name + " with " + mEntity.attacks.get(attacknum).getAttack() + " and did " + mEntity.attacks.get(attacknum).getDamage() + " damage! " + target.name+" died! Farewell "+target.name+".");
target.died(ioHandler, this, player, true);
//>>>> THIS IS WHERE I WOUlD LIKE TO REMOVE 'target' FROM THE env LIST <<<<
} else {
ioHandler.printToConsole("\nThe "+mEntity.name+" attacked "+target.name+" with "+mEntity.attacks.get(attacknum).getAttack()+" and did "+mEntity.attacks.get(attacknum).getDamage()+" damage! "+target.name+" has "+target.health+" health left!");
}
}
}
請憐憫我的編碼技巧,因為我只是 Java / Android 的初學者,盡管非常感謝任何建議!
提前致謝!
如果出於某種原因不使用 Iterator,則可以在迭代集合時收集要在 Set 中刪除的元素,並在循環之后迭代 Set 並從原始集合中刪除元素。
請注意,這僅適用於小型集合。
HashSet toDelete = new HashSet();
for (...) {
if (...)
toDelete.add(item);
}
// end for
foreach (item in toDelete) {
// delete from original collection
}
否則,您只需在迭代器上調用 remove() 即可。
我認為它現在可以添加 toDelete 列表,檢查迭代項是否已經在列表中,如果是,則跳過它,然后刪除它。
我還沒有徹底檢查錯誤,但現在很好。 工作代碼:
public void envActions(IOHandler ioHandler, PlayerClass player){
List<WorldElement> toDelete=new ArrayList<>();
Iterator<WorldElement> worldElementIterator = this.env.iterator();
while(worldElementIterator.hasNext()){
WorldElement worldElement = worldElementIterator.next();
//for(WorldElement worldElement:this.env){
if(worldElement instanceof EntityClass && !toDelete.contains(worldElement)){
EntityClass entity=(EntityClass) worldElement;
if(entity.nature.contains("hostile")){
MonsterClass mEntity=(MonsterClass) entity;
if(!(mEntity.attacks.size()*(Math.random()+0.25)>=mEntity.attacks.size())){
Double followerNum = (Math.random()*player.followers.size());
Integer followerNumInt=followerNum.intValue();
if(followerNumInt<2){
PlayerClass target=player;
Double attacknumD=mEntity.attacks.size()*Math.random();
Integer attacknum= attacknumD.intValue();
Integer playerarmor=player.getArmorValue();
int enemydamage=mEntity.attacks.get(attacknum).getDamage()*(1-(playerarmor/1000));
target.health=target.health-enemydamage;
ioHandler.printToConsole("\nThe "+mEntity.name+" attacked you with "+mEntity.attacks.get(attacknum).getAttack()+" and did "+mEntity.attacks.get(attacknum).getDamage()+" damage! you have "+player.health+" health left!");
} else {
FriendlyCreatureClass target=player.followers.get(followerNumInt);
Double attacknumD=mEntity.attacks.size()*Math.random();
Integer attacknum= attacknumD.intValue();
int enemydamage=mEntity.attacks.get(attacknum).getDamage();
target.health=target.health-enemydamage;
if(!target.isAlive()){
ioHandler.printToConsole("\nThe " + mEntity.name + " attacked " + target.name + " with " + mEntity.attacks.get(attacknum).getAttack() + " and did " + mEntity.attacks.get(attacknum).getDamage() + " damage! " + target.name + " died! Farewell " + target.name + ".");
target.died(ioHandler, this, player, false);
toDelete.add(target);
} else {
ioHandler.printToConsole("\nThe "+mEntity.name+" attacked "+target.name+" with "+mEntity.attacks.get(attacknum).getAttack()+" and did "+mEntity.attacks.get(attacknum).getDamage()+" damage! "+target.name+" has "+target.health+" health left!");
}
}
}
for(WorldElement worldElement:toDelete){
this.env.remove(worldElement);
}
return;
感謝您的快速回復!
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.