java读取大数据量文本

[luozhangwen]

package com.lzw;

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

public class ReadBigFile
{
    public static void main(String[] args) throws IOException
    {
        long start = System.currentTimeMillis();
        readFile("test.txt"); 
        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }


    /**
     * 比用BufferedReader块4倍左右
     */
    public static void readFile(String filePath)
    {
        int buffSize = 1024;
        byte[] bytes = new byte[buffSize];
        ByteBuffer byteBuffer = ByteBuffer.allocate(buffSize);

        FileChannel channel = null;
        try
        {
            channel = new RandomAccessFile(filePath, "r").getChannel(); //"r" = O_RDONLY
//            StringBuffer sb = new StringBuffer(500);
            while (channel.read(byteBuffer) != -1)
            {
                int size = byteBuffer.position();
                byteBuffer.rewind();
                byteBuffer.get(bytes);
                
                String tmp  = new String(bytes, 0, size);
//                System.out.print(tmp); 
                //sb.append(tmp);   //使用这个不需要\n,使用StrinbBuffer数据量超大的时候也会内存溢出
                byteBuffer.clear();
            }
            channel.close();  //pls close in finally
        }
        catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }

}

[yinxiaoqi]

[Quote=引用楼主 luozhangwen 的回复:]
Java code

package com.lzw;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel……
[/Quote]

这个 可以读取文档内容吗？