Java多线程复制文件
不忘初心珂 人气:0/**
* 实现文件复制功能
* 多线程实现文件从一个目录复制到另一个目录
* @param sourceFile:给定源文件路径名
* @param desPath:复制点文件路径
* @return
*/
代码实现如下:
package com.tulun.thread; import java.io.File; import java.io.FileNotFoundException; import java.io.RandomAccessFile; /** * 多线程复制文件 */ public class ThreadCopyFile { public static void main(String[] args) throws Exception { File file = new File("D:\\demo\\erke\\test.txt"); startThread(5, file.length(), "D:\\demo\\erke\\test.txt", "D:\\demo\\erke\\test1.txt"); } /** * 开启多线程复制 * * @param threadnum 线程数 * * @param fileLength 文件大小(用于确认每个线程下载多少东西) * * @param sourseFilePath 源文件目录 * * @param desFilePath 目标文件目录 * */ public static void startThread(int threadnum, long fileLength, String sourseFilePath, String desFilePath) { System.out.println(fileLength); long modLength = fileLength % threadnum; System.out.println("modLength:" + modLength); long desLength = fileLength / threadnum; System.out.println("desLength:" + desLength); for (int i = 0; i < threadnum; i++) { System.out.println((desLength * i) + "-----" + (desLength * (i + 1))); new FileWriteThread((desLength * i), (desLength * (i + 1)), sourseFilePath, desFilePath).start(); } if (modLength != 0) { System.out.println("最后的文件写入"); System.out.println((desLength * threadnum) + "-----" + (desLength * threadnum + modLength)); new FileWriteThread((desLength * threadnum), desLength * threadnum + modLength + 1, sourseFilePath, desFilePath).start(); } } /** * 写线程:指定文件开始位置、目标位置、源文件、目标文件, */ static class FileWriteThread extends Thread { private long begin; private long end; private RandomAccessFile sourseFile; private RandomAccessFile desFile; public FileWriteThread(long begin, long end, String sourseFilePath, String desFilePath) { this.begin = begin; this.end = end; try { this.sourseFile = new RandomAccessFile(sourseFilePath, "rw"); this.desFile = new RandomAccessFile(desFilePath, "rw"); } catch (FileNotFoundException e) { } } public void run() { try { sourseFile.seek(begin); desFile.seek(begin); int hasRead = 0; byte[] buffer = new byte[1]; while (begin < end && -1 != (hasRead = sourseFile.read(buffer))) { begin += hasRead; desFile.write(buffer, 0, hasRead); } } catch (Exception e) { e.printStackTrace(); } finally { try { sourseFile.close(); desFile.close(); } catch (Exception e) { } } } } }
运行结果:
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