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Java.io.StreamTokenizer.nextToken()方法實例

java.io.StreamTokenizer.nextToken() 方法分析從標記生成器的輸入流中的下一個標記。下一個標記的類型在ttype字段中返回。關於令牌的附加信息可能是在nval字段或標記生成器的sval 字段。這一類的典型客戶端首次設置語法表,然後坐在一個循環調用nextToken的解析連續的標記,直到TT_EOF返回。

聲明

以下是java.io.StreamTokenizer.nextToken()方法聲明

public int nextToken()

參數

  • NA

返回值

此方法返回ttype字段的值。

異常

  • IOException -- 如果發生I/O錯誤。

例子

下麵的示例演示java.io.StreamTokenizer.nextToken()方法的用法。

package com.yiibai;

import java.io.*;

public class StreamTokenizerDemo {

   public static void main(String[] args) {

      String text = "Hello. This is a text 
 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);

         // 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();
      }
   }
}

讓我們編譯和運行上麵的程序,這將產生以下結果:

Word: Hello.
Word: This
Word: is
Word: a
Word: text
Word: that
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.