Java.io.StreamTokenizer Class in Java | Set 2

StringTokenizer Class in Java | Set 1

Methods:

1. parseNumbers() : java.io.StreamTokenizer.parseNumbers() specifies that the number in StreamTokenizer is parsed, so that each character – ” 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ” has a numeric attribute.
   When the parser encounters a word token that has the format of a double precision floating-point number, it treats the token as a number rather than a word, by setting the ttype field to the value TT_NUMBER and putting the numeric value of the token into the nval field.
   Syntax :

   public void parseNumbers()
   Parameters :
   -----------
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program  illustrating use of parseNumbers() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,     FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);            // Use of parseNumbers() method         // specifies that the number in StreamTokenizer is parsed          token.parseNumbers();            int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_NUMBER:                 System.out.println("Number : " + token.nval);                 break;             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;                }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   Hello Geeks 1
   This 2
   3is
   about 4
   parseNumbers()

   Output :

   Word : Hello
   Word : Geeks
   Number : 1.0
   Word : This
   Number : 2.0
   Number : 3.0
   Word : is
   Word : about
   Number : 4.0
   Word : parseNumbers

2. quoteChar() : java.io.StreamTokenizer.quoteChar(int arg) specifies that it delimits the matching character as string constant in StreamTokenizer.
   When the nextToken method encounters a string constant, the ttype field is set to the string delimiter and the sval field is set to the body of the string.
   Syntax :

   public void quoteChar(int arg)
   Parameters :
   arg : the character to be dilimit 
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program  illustrating use of quoteChar() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,                                              FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);            // specify o as a quote char         token.quoteChar('o');            int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;             case StreamTokenizer.TT_NUMBER:                 System.out.println("Number : " + token.nval);                 break;             default:                 System.out.println((char) t + " encountered.");                }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   Hello
   Geeks
   This
   is
   about
   quoteChar()

   Output :

   Word : Hell
   o encountered.
   Word : Geeks
   Word : This
   Word : is
   Word : ab
   o encountered.
   Word : qu
   o encountered.

3. resetSyntax() : java.io.StreamTokenizer.resetSynatx() resets Syntax when a number is met, so that all characters are set as ‘Ordinary’ in StreamTokenizer.
   Syntax :

   public void resetSyntax()
   Parameters :
   ---------
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program  illustrating use of resetSyntax() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,                                              FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);                      int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;             case StreamTokenizer.TT_NUMBER:                                     // Use of resetSyntax()                   token.resetSyntax();                    System.out.println("Number : " + token.nval);                 break;             default:                 System.out.println((char) t + " encountered.");                }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   Hello
   This
   is
   resetSyntax()
   1 xmpl
   2 🙂
   3
   Output :

   Word : Hello
   Word : This
   Word : is
   Word : resetSyntax
   ( encountered.
   ) encountered.
   Number : 1.0
     encountered.
   x encountered.
   m encountered.
   p encountered.
   l encountered.
    encountered.
   
    encountered.
   2 encountered.
     encountered.
   : encountered.
   ) encountered.
    encountered.
   
    encountered.
   3 encountered.

4. slashSlashComments() : java.io.StreamTokenizer.slashSlashComments(boolean arg) specifies whether to consider C++ – style comments by tokenizer or not. If ‘arg’ is set true, then the StreamTokenizer recognises and ignores C++ – style comments. ‘//’ is considered as starting of a comment.
   If the flag argument is false, then C++- style comments are not treated specially.
   Syntax :

   public void slashSlashComments(boolean arg)
   Parameters :
   arg : tells whether to recognise and ignore C++ - style comments or not.
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program  illustrating use of slashSlashComments() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,                                                FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);            // Use of slashSlashComments()         // Here 'arg' is set to true i.e. to recognise and ignore C++style Comments         boolean arg = true;         token.slashSlashComments(arg);            int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;             case StreamTokenizer.TT_NUMBER:                 System.out.println("Number : " + token.nval);                 break;             }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   This program is about slashSlashComments // method

   This method considers ‘method’ in ABC.txt file as an comment and thus ignores it.
   Output :

   Word : This
   Word : program
   Word : is
   Word : about
   Word : slashSlashComments

5. slashStarComments() : java.io.StreamTokenizer.slashStarComments(boolean arg) specifies whether to consider C – style comments by tokenizer or not. If ‘arg’ is set true, then the StreamTokenizer recognises and ignores C – style comments. ‘/*……*/’ is considered as a comment.
   Syntax :

   public void slashStarComments(boolean arg)
   Parameters :
   arg : tells whether to recognise and ignore C - style comments or not.
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program illustrating use of slashStarComments() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,                                               FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);            // Use of slashStarComments()         // Here 'arg' is set to true i.e. to recognise and ignore Cstyle Comments         boolean arg = true;         token.slashStarComments(true);            int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;             case StreamTokenizer.TT_NUMBER:                 System.out.println("Number : " + token.nval);                 break;             }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   This program is about slashStarComments /* method */ 123

   This method considers ‘method’ in ABC.txt file as an comment and thus ignores it.
   Output :

   Word : This
   Word : program
   Word : is
   Word : about
   Word : slashStarComments
   Number : 123.0

6. whitespaceChars() : java.io.StreamTokenizer.whitespaceChars(int low, int high) specifies all the characters in the range of low to high as white space, which serves only to separate tokens in the InputStream.
   Syntax :

   public void whitespaceChars(int low, int high)
   Parameters :
   low : lower range of character to be white spaced.
   high : higher range of character to be white spaced 
   Return :
   void

   Implementation :

   
   

   
   
   

   // Java Program illustrating use of whitespaceChars() method    import java.io.*; public class NewClass {     public static void main(String[] args) throws InterruptedException,                                          FileNotFoundException, IOException     {         FileReader reader = new FileReader("ABC.txt");         BufferedReader bufferread = new BufferedReader(reader);         StreamTokenizer token = new StreamTokenizer(bufferread);                     // Use of whitespaceChars() method         // Here range is low = 'a' to high = 'c'         token.whitespaceChars('a','d');            int t;         while ((t = token.nextToken()) != StreamTokenizer.TT_EOF)         {             switch (t)             {             case StreamTokenizer.TT_WORD:                 System.out.println("Word : " + token.sval);                 break;             case StreamTokenizer.TT_NUMBER:                 System.out.println("Number : " + token.nval);                 break;             }         }     } }

   Note :
   This program won’t run here as no ‘ABC’ file exists. You can check this code on Java compiler on your system.
   To check this code, create a file ‘ABC’ on your system.
   ‘ABC’ file contains :

   This program is about whitespaceChars()

   Output :

   Word : This
   Word : progr
   Word : m
   Word : is
   Word : out
   Word : whitesp
   Word : eCh
   Word : rs

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