中财网雅芳新自然系列组合套:Java多线程文件复制
来源：百度文库 编辑：中财网 时间：2024/05/03 06:21:35
package com.ff;
import java.io.*;
import java.util.RandomAccess;
public class Demo{
public static void main(String[] args) throws Exception{
File srcFile=new File("源文件路径");
File orgFile=new File("目标文件路径");
//orgFile.createNewFile();
Demo demo=new Demo();
demo.analysisFile(srcFile,orgFile,4);//4为线程数，你也可以修改为其他数值
}
public void analysisFile(File srcFile,File orgFile,int threadNum){
int length=(int)srcFile.length();
int splitNum=length%threadNum==0?length/threadNum:length/threadNum+1;
int skipPostion=-1;
int readNum=0;
for(int i=1;i<=threadNum;i++){
if(i!=threadNum){
readNum=i*splitNum;
}
else{
readNum=length-readNum;
}
new SplitFile(srcFile,orgFile,skipPostion+1,readNum).start();
skipPostion=i*splitNum;
}
}
class SplitFile extends Thread{
private int minPosition;
private int maxPosition;
private File srcFile;
private File orgFile;
public SplitFile(File srcFile,File orgFile,int minPosition,int maxPosition){
this.maxPosition=maxPosition;
this.minPosition=minPosition;
this.srcFile=srcFile;
this.orgFile=orgFile;
}
public void run(){
try{
RandomAccessFile raf_r=new RandomAccessFile(srcFile,"rw");
RandomAccessFile raf_w=new RandomAccessFile(orgFile,"rw");
raf_r.skipBytes(minPosition);
raf_w.seek(minPosition);
byte[] buf=new byte[1];
int alreadyRec=0;
for(int size=0;alreadyRec<=maxPosition&&size!=-1;size=raf_r.read(buf)){
alreadyRec+=size;
raf_w.write(buf,0,size);
}
raf_w.close();
raf_r.close();
System.out.println("总共:"+srcFile.length()+" 文件"+srcFile.getName()+"从:"+minPosition+"开始---复制大小:"+maxPosition+"结束!此刻接收文件大小为:"+orgFile.length());
}
catch(Exception ex){
ex.printStackTrace();
}
}
}
}