Java RandomAccessFile getFilePointer()用法及代码示例

RandomAccessFile类getFilePointer()方法

• getFilePointer() 方法可在java.io包。
• getFilePointer() 方法用于获取 RandomAccessFile 流中的当前指针。
• getFilePointer() 方法是一个非静态方法，它只能通过类对象访问，如果我们尝试使用类名访问方法，那么我们将得到一个错误。
• getFilePointer() 方法在返回文件指针时不抛出异常。

用法:

    public long getFilePointer();

参数：

• 它不接受任何参数。

返回值：

这个方法的返回类型是long，它返回下一次读取或写入发生的文件开头的指针。

例：

// Java program to demonstrate the example 
// of long getFilePointer() method of
// RandomAccessFile

import java.io.*;

class RAFGetFilePointer {
 public static void main(String[] args) throws Exception {
  // Instantiate a random access file
  // object with file name and permissions
  RandomAccessFile ra_f = new RandomAccessFile("e:/includehelp.txt", "rw");

  // By using writeUTF() method is to 
  // write data in the file
  ra_f.writeUTF("Welcome, in Java World!!!");

  // Initially set the file pointer
  // is at 0 for reading the file
  ra_f.seek(0);

  // To read file content by using
  // readUTF()
  System.out.println("ra_f .readUTF():" + ra_f.readUTF());

  // By using getFilePointer() method is to
  // return the file pointer in bytes at which
  // the next read/write occurs
  System.out.println("ra_f.getFilePointer():" + ra_f.getFilePointer());

  // By using close() method isto
  // close this stream ran_f
  ra_f.close();
 }
}

输出

ra_f .readUTF():Welcome, in Java World!!!
ra_f.getFilePointer():27