niodemo.java

社区文章采用的是平板、树形自由选择的两种展示方式

/*
 * Created on 2005-8-30
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package com.yeqiangwei.club.ip;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

/**
 * @author wang
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class NIODemo
{

    String ipFile="E:\\QQWry.dat";
    RandomAccessFile file=null;
    FileChannel fc=null;
    MappedByteBuffer mbb=null;
    /**
     * 
     */
    public NIODemo()
    {
        super();
        // TODO Auto-generated constructor stub
    }
    public void init()
    {
        try
        {
            file=new RandomAccessFile(ipFile, "r");
            fc=file.getChannel();
            System.out.println(file.length());
            //mbb=fc.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
        
        } catch (FileNotFoundException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
         
    }
    public String getString()
    {
        byte[] rs=new byte [1024];
        String result="";
        ByteBuffer bb=mbb.get(rs,0,1024);
        char [] c=new char[bb.capacity()];
        for(int i=0;i<1024/4;i++)
        {
            c[i]=bb.getChar(i);
        }
        result = new String(c);
        String s = IPUtils.getString(result,"gb2312","utf-8");
        return s;
    }
    public void destory()
    {
        try
        {
            mbb.clear();
            fc.close();
            file.close();
        } catch (IOException e1)
        {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
    }
    public static void main(String[] args)
    {
        NIODemo nio=new NIODemo();
        nio.init();
        System.out.println(nio.getString());
        nio.destory(); 
    }
}