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PONullpointer exception when adding to list
primarykey
Id
17002278
data
AcceptedAnswerId
17002373
AnswerCount
6
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2013-06-08T17:57:05.457
FavoriteCount
0
LastActivityDate
2013-07-05T04:20:49.907
LastEditDate
2013-06-08T18:24:03.800
LastEditorUserId
2423419
OwnerUserId
2423419
ParentId
0
PostTypeId
1
Score
0
ViewCount
6399
LastEditorDisplayName
text
Body
I am trying to iterate through a list of objects to figure out which ones are fighting each other. I am using the <code>checkedGladiators</code> list as something to compare against to prevent it from checking gladiators already assigned to a combat, as each <code>s</code> that isn't assigned already will build their entire combat around them. Currently I get a <code>NullPointerException</code>, so I used some test text to figure that it was happening right at <code>listContains(checkedGladiators,s)</code>. I added the part before it. NOW the problem is happening between "Null" and "Null Changed" as well, which makes no sense to me. <pre><code>for (Gladiator s : gladiators){ if (checkedGladiators == null) { System.out.println("Null"); combat1.add(s); checkedGladiators.add(s); System.out.println("Null Changed"); } if (listContains(checkedGladiators,s)) { // if gladiator is already in a combat do nothing } else { // if he isn't } </code></pre> } listContains class: <pre><code>public boolean listContains(List<Gladiator> List, Gladiator search) { for (Gladiator p : List) { if (p.equals(search)) { return true; } } return false; } </code></pre> Does anyone know why this would occur? Thanks Edit1: <pre><code>public class Ai { private List<Gladiator> gladiators; private List<List<Gladiator>> combatsList; private List<Gladiator> checkedGladiators; private List<Gladiator> combat1; private List<Gladiator> combat2; private List<Gladiator> combat3; private List<Gladiator> combat4; private List<Gladiator> combat5; private List<Gladiator> combat6; private List<Gladiator> combat7; private List<Gladiator> combat8; private List<Gladiator> guardList; private List<Gladiator> advanceList; private List<Gladiator> retreatList; int totalCombats = 0; // total combats going on </code></pre> I have initialized the list variable in the class already.
Tags
<java><list><nullpointerexception>
Title
Nullpointer exception when adding to list
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USPeter F
UserOwnerUserId
1. USPeter F
plurals
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1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
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 PTAnswer
3. PO
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VotesPostIdCreationDate
1. This table or related slice is empty.
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