writerandomaccessfile.java

精通java核心技术》随书源代码

import java.io.*;

   public class WriteRandomAccessFile
  {
       public static void main(String[] args)
      {
	        try {
	            long dataPosition = 0; 
	            int data = 123;
               RandomAccessFile raf = new RandomAccessFile("datafile", "rw");
			   raf.writeLong(0); 
	            raf.writeChars("hello world");
	            dataPosition = raf.getFilePointer();
	            raf.writeInt(data);
	            raf.writeUTF("hello java");
               raf.seek(0);  //重写第一个字节
               raf.writeLong(dataPosition);
               System.out.println("WRITE FILE SUCCESS");
	            raf.close();
           } 
           catch (FileNotFoundException e) 
           {
               System.err.println("This shouldn't happen: " + e);
           }
	         catch (IOException e) 
 		    {
	            System.err.println("Writing error: " + e);
            }
        }
    }