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Java.io.StreamTokenizer.eolIsSignificant()方法实例

java.io.StreamTokenizer.eolIsSignificant(boolean flag) 方法确定行尾是否被视为令牌。如果flag参数为true,此标记生成器把线作为标记的结束; nextToken方法返回TT_EOL并且还设置了ttype字段中这个值时,行尾被读取。 一行是不符合任何一个回车符(' ')或换行符(' ')结尾的字符序列。此外,一个回车符紧跟一个换行符被视为行尾单令牌。如果标志为false,行尾的字符都被视为空白和它的作用只是单独的令牌。

声明

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

public void eolIsSignificant(boolean flag)

参数

  • flag --true表示行尾的字符都是分隔标记; false表示行尾的字符是空白。

返回值

此方法不返回任何值。

异常

  • NA

例子

下面的示例演示java.io.StreamTokenizer.eolIsSignificant()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);

         // 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();
      }
   }
}

让我们来编译和运行上面的程序,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.