Java.io.StreamTokenizer.eolIsSignificant() 方法

描述

java.io.StreamTokenizer.eolIsSignificant(boolean flag) 方法确定是否线的端部作为标记处理。如果 flag 参数为 true，则此标记生成器将行尾视为标记；nextToken 方法返回 TT_EOL 并在读取行尾时将 ttype 字段设置为此值。一行是以回车符 ('\r') 或换行符 ('\n') 结尾的字符序列。此外，紧跟换行符的回车符被视为单个行尾标记。如果该标志为 false，则行尾字符将被视为空格并仅用于分隔标记。

声明

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

 public void eolIsSignificant(boolean flag)

参数

flag - true表示行尾字符是单独的标记；false表示行尾字符是空格。

返回值

此方法不返回值。

异常

N/a

例子

以下示例显示java.io.StreamTokenizer.eolIsSignificant()方法的用法。

 
package com.jc2182;

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 that end of line is significant
         st.eolIsSignificant(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();
      }
   }
}

让我们编译并运行以上程序，这将产生以下结果-

 
Word: Hello.
Word: This
Word: is
Word: a
Word: text
End of Line encountered.
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.