Java学习日记1——多线程拷贝文件

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一、摘要

前面学习了IO流，写了拷贝文件的功能；接着学习了多线程，现在将两个知识结合起来，来实现多线程拷贝文件。

二、代码

package com.softeem.work;import java.io.File;import java.io.FileNotFoundException;import java.io.IOException;import java.io.RandomAccessFile;import java.util.Date;public class ThreadCopyFile extends Thread{private File file;//被拷贝的文件private File dir;//将要拷贝的目录private long start;//当前进程拷贝文件的起始位置private long end;//当前进程拷贝文件的末位置public ThreadCopyFile(File file, File dir, long start,long end) {super();this.file = file;this.dir = dir;this.start = start;this.end = end;}@Overridepublic void run() {RandomAccessFile raf_read = null;RandomAccessFile raf_write = null;int len = 0;int position = 0;long s1 = 0;long s2 = 0;try {raf_read = new RandomAccessFile(file,"r");File targetFile = new File(dir,file.getName());raf_write  = new RandomAccessFile(targetFile,"rw");byte[] b = new byte[1024*1024*10];System.out.println("线程"+this.getName()+"准备开始拷贝");System.out.println("线程"+this.getName()+"正在拷贝");raf_read.seek(start);//从start位置读raf_write.seek(start);//从start位置写while((len = raf_read.read(b)) != -1 && position <(end - start)){raf_write.write(b,0,len);position += len;}System.out.println("线程" + this.getName()+ "拷贝完成!");} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}finally{try {if(raf_read != null)raf_read.close();if(raf_write != null)raf_write.close();} catch (IOException e) {e.printStackTrace();}}}public static void main(String[] args) {File file = new File("E:\\原目录\\测试文件.zip");File dir = new File("E:\\测试目录");long size = file.length();int j = 2;//设置线程数for (int i = 0; i < j; i++) {new ThreadCopyFile(file, dir, size*i/j, size*(i+1)/j).start();//根据线程数分割文件}}}

三、结果截图

四、总结

以后继续学习，希望追加进度监控和计时的功能

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