RandomAccessFile将文件内容逆序输出

package com.lwf.io;

import java.awt.Container;
import java.io.IOException;
import java.io.RandomAccessFile;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class TestRandomAccessFile {

	public static void main(String[] args) {

		 RandomAccessFile in = null;
		  try {
		   in = new RandomAccessFile("d:/ui.txt", "rw");
		   long length = in.length(); //获取文件的长度
		   long i=length-1;
		   char ch;
		   String s="";
		   while(i>=0){
		    in.seek(i);//设置文件指针
		    ch = (char) in.read();
		    s += ch;
		    i--;
		   }
		  
		   System.out.println(s);
		   showText(s);
		  } catch (IOException e) {
		  }

}
	 public static void showText(String s){
		  JFrame f=new JFrame("SetText");//frame
		  f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//close
		  f.setBounds(200, 200, 400, 200);//location,sise
		  Container content=f.getContentPane();//panel
		  JPanel p=new JPanel();
		  JTextArea t=new JTextArea();//area
		  JScrollPane scrollPane=new JScrollPane(t);//scroll
		  t.setRows(1);//row
		  t.setColumns(10);//col
		  t.setText(s);//set text
		  p.add(scrollPane);
		  content.add(p);
		  f.setVisible(true);
		 }
}

 

本示例将文件里面的内容逆序输出在文本框中，并可通过滚动条滚动查看。