Java.io.StreamTokenizer slashStarComments() 方法

描述

java.io.StreamTokenizer.slashStarComments(boolean flag) 方法決定標記器是否識別 C 樣式註釋。如果 flag 引數為 true，則此流標記器識別 C 樣式註釋。/* 和 */ 之間的全部文字將被丟棄。

如果 flag 引數為 false，則 C 樣式註釋不會被特殊處理。

宣告

以下是 java.io.StreamTokenizer.slashStarComments() 方法的宣告。

public void slashStarComments(boolean flag)

引數

flag − true 表示識別並忽略 C 樣式註釋。

返回值

此方法不返回值。

異常

無

示例

以下示例顯示了 java.io.StreamTokenizer.slashStarComments() 方法的使用。

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 slash-star comments as recognizable
         st.slashStarComments(true);

         // 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();
      }
   }
}

讓我們編譯並執行上述程式，這將產生以下結果：

Word: EHello.
Word: This
Word: will
Word: be
Word: split
Word: into
Word: tokens.
Number: 1.0
+ encountered.
Number: 1.0
= encountered.
Number: 2.0
End of File encountered.