Java - StreamTokenizer whitespaceChars(int low, int hi) method

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Description

The Java StreamTokenizer whitespaceChars(int low, int hi) method specifies that all characters c in the range low <= c <= high are white space characters. White space characters serve only to separate tokens in the input stream. Any other attribute settings for the characters in the specified range are cleared.

Declaration

Following is the declaration for java.io.StreamTokenizer.whitespaceChars(int low, int hi) method.

 public void whitespaceChars(int low, int hi) 

Parameters

• low − The low end of the range.

• high − The high end of the range.

Return Value

This method does not return a value.

Exception

NA

Example - Usage of StreamTokenizer whitespaceChars(int low, int hi) method

The following example shows the usage of StreamTokenizer whitespaceChars(int low, int hi) method.

StreamTokenizerDemo.java

 package com.tutorialspoint; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStreamReader; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Reader; import java.io.StreamTokenizer; public class StreamTokenizerDemo { public static void main(String[] args) { String text = "Hello. This is a text \n that will be split " + "into tokens. 1 + 1 = 2"; try { // create a new file with an ObjectOutputStream FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // write something in the file oout.writeUTF(text); oout.flush(); // create an ObjectInputStream for the file we created before ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // create a new tokenizer Reader r = new BufferedReader(new InputStreamReader(ois)); StreamTokenizer st = new StreamTokenizer(r); // set letters o- t as white space chars st.whitespaceChars('o', 't'); // print the stream tokens boolean eof = false; do { int token = st.nextToken(); switch (token) { case StreamTokenizer.TT_EOF: System.out.println("End of File encountered."); eof = true; break; case StreamTokenizer.TT_EOL: System.out.println("End of Line encountered."); break; case StreamTokenizer.TT_WORD: System.out.println("Word: " + st.sval); break; case StreamTokenizer.TT_NUMBER: System.out.println("Number: " + st.nval); break; default: System.out.println((char) token + " encountered."); if (token == '!') { eof = true; } } } while (!eof); } catch (Exception ex) { ex.printStackTrace(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 Word: AHell Number: 0.0 Word: Thi Word: i Word: a Word: ex Word: ha Word: will Word: be Word: li Word: in Word: ken Number: 0.0 Number: 1.0 + encountered. Number: 1.0 = encountered. Number: 2.0 End of File encountered. 

Example - Treat comma (,) and space as whitespace

The following example shows the usage of StreamTokenizer whitespaceChars(int low, int hi) method.

StreamTokenizerDemo.java

 package com.tutorialspoint; import java.io.IOException; import java.io.Reader; import java.io.StreamTokenizer; import java.io.StringReader; public class StreamTokenizerDemo { public static void main(String[] args) throws IOException { String input = "Java,Python C++"; Reader reader = new StringReader(input); StreamTokenizer tokenizer = new StreamTokenizer(reader); // Treat space and comma as whitespace tokenizer.whitespaceChars(32, 32); // space tokenizer.whitespaceChars(',', ','); // comma tokenizer.wordChars('a', 'z'); tokenizer.wordChars('A', 'Z'); tokenizer.wordChars('+', '+'); // to include '+' in C++ System.out.println("Tokens:"); while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) { if (tokenizer.ttype == StreamTokenizer.TT_WORD) { System.out.println("Word: " + tokenizer.sval); } } } } 

Output

Let us compile and run the above program, this will produce the following result−

 Tokens: Word: Java Word: Python Word: C++ 

Explanation

• Both comma and space are whitespace, so tokens are split by them.

• They don't appear in the output.

Example - Treat digits 0-9 as whitespace (stripping them out)

The following example shows the usage of StreamTokenizer whitespaceChars(int low, int hi) method.

StreamTokenizerDemo.java

 package com.tutorialspoint; import java.io.IOException; import java.io.Reader; import java.io.StreamTokenizer; import java.io.StringReader; public class StreamTokenizerDemo { public static void main(String[] args) throws IOException { String input = "a1b2c3"; Reader reader = new StringReader(input); StreamTokenizer tokenizer = new StreamTokenizer(reader); tokenizer.whitespaceChars('0', '9'); // treat all digits as whitespace tokenizer.wordChars('a', 'z'); tokenizer.wordChars('A', 'Z'); System.out.println("Tokens:"); while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) { if (tokenizer.ttype == StreamTokenizer.TT_WORD) { System.out.println("Word: " + tokenizer.sval); } } } } 

Output

Let us compile and run the above program, this will produce the following result−

 Tokens: Word: a Word: b Word: c 

Explanation

• The digits 1, 2, and 3 are treated as whitespace.

• They are used to split the words but do not appear as tokens.