Java using scanner enter key pressed

Question

I am programming using Java  I am trying write code which can recognize if the user presses the enter key in a console based program   How can I do this using java  I have been told that this can be done using either Scanner or  buffered input reader  I do not understand or know how to use  buffered input reader   I tried to do do this using scanner but after pressing enter twice the program terminates  and it doesn t work      Scanner readinput   new Scanner System in        String enterkey    Hola       System out print enterkey         enterkey   readinput nextLine         System out print enterkey        if enterkey                  System out println  It works       Thanks     -- edit -- the following code works using the equals method for the string instead of         Scanner readinput   new Scanner System in        String enterkey    Hola       System out print enterkey         enterkey   readinput nextLine         System out print enterkey        if enterkey equals                System out println  It works       how can this be done  and what are the pros to doing this using the buffered input reader

User · Answer

Scanner scan   new Scanner System in           int i   scan nextInt            Double d   scan nextDouble              String newStr               Scanner charScanner   new Scanner  System in   useDelimiter      b   B               while  charScanner hasNext                    String  c   charScanner next                 if  c equalsIgnoreCase   r                      break                            else                   newStr    c                                       System out println  String      newStr           System out println  Int      i           System out println  Double      d     This code works fine

User · Answer

This works using java util Scanner and will take multiple  enter  keystrokes       Scanner scanner   new Scanner System in       String readString   scanner nextLine        while readString  null            System out println readString            if  readString isEmpty                  System out println  Read Enter Key                        if  scanner hasNextLine                  readString   scanner nextLine              else               readString   null                    To break it down   Scanner scanner   new Scanner System in   String readString   scanner nextLine      These lines initialize a new Scanner that is reading from the standard input stream  the keyboard  and reads a single line from it       while readString  null            System out println readString     While the scanner is still returning non-null data  print each line to the screen           if  readString isEmpty                  System out println  Read Enter Key                 If the  enter   or return  or whatever  key is supplied by the input  the nextLine   method will return an empty string  by checking to see if the string is empty  we can determine whether that key was pressed   Here the text Read Enter Key is printed  but you could perform whatever action you want here           if  scanner hasNextLine                  readString   scanner nextLine              else               readString   null              Finally  after printing the content and or doing something when the  enter  key is pressed  we check to see if the scanner has another line  for the standard input stream  this method will  block  until either the stream is closed  the execution of the program ends  or further input is supplied

[java] Java using scanner enter key pressed

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