Java.io.StreamTokenizer.whitespaceChars() 方法

描述

java.io.StreamTokenizer.whitespaceChars(int low, int hi) 方法指定范围 low <= c <= high 内的所有字符 c 都是空白字符。空白字符仅用于分隔输入流中的标记。指定范围内的字符的任何其他属性设置都将被清除。

声明

以下是java.io.StreamTokenizer.whitespaceChars() 方法的声明。

public void whitespaceChars(int low, int hi)

参数

• low − 范围的下限。

• high − 范围的上限。

返回值

此方法不返回值。

异常

无

示例

以下示例演示了java.io.StreamTokenizer.whitespaceChars() 方法的用法。

package com.tutorialspoint;

import java.io.*;

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();
      }
   }
}

让我们编译并运行上述程序，这将产生以下结果：

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.