testrafile.java

java课件及例程有一些PPT及一些例程

import java.io.*;
public class TestRAFile{
    public static void main(String[] args){
        File f = new File("file.txt");
        int i,j=0;
        try{
            RandomAccessFile raf = new RandomAccessFile(f,"rw");
            System.out.println("文件的长度为"+raf.length());
            i = raf.readByte();
            System.out.println((char) i); 
            System.out.println("当前指针的位置为："+raf.getFilePointer());
            raf.seek(10);
            while(j<6){
                System.out.print((char)raf.readByte()); 
                j++;
            }
            System.out.println();
            j=0; 
            raf.skipBytes(6);
            System.out.println((char)raf.readByte()); 
            System.out.println("当前指针的位置为："+raf.getFilePointer());
            raf.seek(0);
            while((i = raf.read())!=-1)
                System.out.print((char)i);
            System.out.println();
            raf.setLength(10);
            System.out.println("运行setLength方法后，文件的长度为："+raf.length());
            raf.seek(0);
            while((i = raf.read())!=-1)
                System.out.print((char)i);           
        }
        catch(EOFException e){
            System.out.println("已经读到文件末尾");
        }
        catch(IOException e){System.out.println(e.getMessage());}
    }
}