Java.io.StreamTokenizer.lineno() 方法

  • 描述

    java.io.StreamTokenizer.lineno() 方法返回的当前行号。
  • 声明

    以下是java.io.StreamTokenizer.lineno()方法的声明。
     public void lineno()
  • 参数

    N/A
  • 返回值

    此方法返回此流标记器的当前行号。
  • 异常

    N/a
  • 例子

    以下示例显示java.io.StreamTokenizer.lineno()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 line change as significant
             st.eolIsSignificant(true);
    
             // print the current line number
             System.out.println("Line Number:" + st.lineno());
    
             // 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.");
                      System.out.println("Line Number:" + st.lineno());
                      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-
     
    Line Number:1
    Word: Hello.
    Word: This
    Word: is
    Word: a
    Word: text
    End of Line encountered.
    Line Number:2
    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.