Scanner is never closed

Question

I m working on a game and I came across a little problem with my scanner  I m getting a resource leak scanner never closed   But I thought my scanner was working before without closing it  But now it ain t  Anyone can help me out here   import java util Scanner   public class Main        public static final boolean CHEAT   true       public static void main String   args             Scanner scanner   new Scanner System in           int amountOfPlayers          do               System out print  Select the amount of players  1 2                   while   scanner hasNextInt                      System out println  That s not a number                     scanner next       this is important                     amountOfPlayers   scanner nextInt            while   amountOfPlayers  lt   0      amountOfPlayers  gt  2            System out println  You ve selected     amountOfPlayers   player s

User · Answer

According to the Javadoc of Scanner  it closes the stream when you call it s close method  Generally speaking  the code that creates a resource is also responsible for closing it  System in was not instantiated by by your code  but by the VM  So in this case it s safe to not close the Scanner  ignore the warning and add a comment why you ignore it  The VM will take care of closing it if needed    Offtopic  instead of  amount   the word  number  would be more appropriate to use for a number of players  English is not my native language  I m Dutch  and I used to make exactly the same mistake

User · Answer

I am assuming you are using java 7  thus you get a compiler warning  when you don t close the resource you should close your scanner usually in a finally block   Scanner scanner   null  try       scanner   new Scanner System in         rest of the code   finally       if scanner  null          scanner close        Or even better  use the new Try with resource statement   try Scanner scanner   new Scanner System in          rest of your code

User · Answer

Try this  Scanner scanner   new Scanner System in   int amountOfPlayers  do       System out print  Select the amount of players  1 2           while   scanner hasNextInt              System out println  That s not a number             scanner next       this is important             amountOfPlayers   scanner nextInt      while   amountOfPlayers  lt   0      amountOfPlayers  gt  2    if scanner    null        scanner close      System out println  You ve selected     amountOfPlayers   player s

User · Answer

Here is some better usage of java for scanner  try Scanner sc   new Scanner System in            Use sc as you need    catch  Exception e                 handle exception

[java] Scanner is never closed

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