package FileCopyThread; //自建的包，根据个人调整 import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; public class FileCopy { public static void main(String[] args) { int start = (int)System.currentTimeMillis(); try { RandomAccessFile raf = new RandomAccessFile(new File("E:/11.txt"), "r"); int fileLen = (int)raf.length(); int nums = 20; int distance = (int)(fileLen/nums); new ThreadFileCopy(0, distance - 1).start();; for(int i = 1; i <= nums - 2; i++){ new ThreadFileCopy(distance*i, distance*(i+1) - 1).start(); } new ThreadFileCopy(distance*(nums-1), fileLen).start(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } int end = (int)System.currentTimeMillis(); System.out.println("耗时：" + (end - start)); } }
package FileCopyThread; //自建的包根据个人调整 import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; public class ThreadFileCopy extends Thread{ final String oldPath = "E:/11.txt"; final String newPath = "F:/22.txt"; RandomAccessFile oraf = null; RandomAccessFile nraf = null; private int startPos = 0; private int endPos = 0; final int bufSize = 10240 * 5; public ThreadFileCopy(){ } public ThreadFileCopy(int startPos, int endPos){ this.startPos = startPos; this.endPos = endPos; } @Override public void run() { try { oraf = new RandomAccessFile(new File(oldPath), "r"); nraf = new RandomAccessFile(new File(newPath), "rw"); oraf.seek(startPos); nraf.seek(startPos); byte[] bytes = new byte[bufSize]; int len; while(endPos - startPos > 0){ len = (int)((endPos - startPos) > bufSize ? bufSize :(endPos - startPos)); oraf.read(bytes, 0, len); nraf.write(bytes, 0, len); endPos -= len; System.out.println(Thread.currentThread().getName() + "读取了" + len + "个字节"); } oraf.close(); nraf.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { } } }
