我的程序正在将所有数据从外部驱动器复制到我电脑上的特定位置。
这是我的程序:-
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class Copy
{
public static void main(String[] args)
{
String[] letters = new String[]{"A", "B", "C", "D", "E", "F", "G", "H", "I"};
File[] drives = new File[letters.length];
int copy=0;int l;File files[]=null;boolean pluggedIn=false;
FileInputStream fis=null;
FileOutputStream fos=null;
boolean[] isDrive = new boolean[letters.length];
for (int i = 0; i < letters.length; ++i)
{
drives[i] = new File(letters[i] + ":/");
isDrive[i] = drives[i].canRead();
}
System.out.println("FindDrive: waiting for devices...");
while (true)
{
try
{
for (int i = 0; i < letters.length; ++i)
{
pluggedIn = drives[i].canRead();
if (pluggedIn != isDrive[i])
{
if (pluggedIn)
{
System.out.println("Drive " + letters[i] + " has been plugged in");
files = drives[i].getAbsoluteFile().listFiles();
File file;
int fread;
for (l = 0; l < files.length; l++)
{
if (files[l].isFile())
{
file = new File("G://copied//" + files[l].getName());
file.createNewFile();
fis = new FileInputStream(drives[i].getAbsolutePath() + files[l].getName());
fos = new FileOutputStream(file);
while (true)
{
fread = fis.read();
if (fread == -1)
{
break;
}
fos.write(fread);
}
}
else
{
func(files[l].getAbsoluteFile(), "G://copied");
}
if(l==files.length-1)
{
System.out.print("copy complete");
fos.close();
fis.close();
}
}
}
else
{
System.out.println("Drive " + letters[i] + " has been unplugged");
}
isDrive[i] = pluggedIn;
}
}
Thread.sleep(5000);
}
catch (FileNotFoundException e) { }
catch (IOException e) { }
catch (InterruptedException e) {}
}
}
public static void func(File dir, String path)
{
File file = new File(path + "//" + dir.getName());
file.mkdir();
File[] files = dir.listFiles();
FileInputStream fis;
FileOutputStream fos;
int fread;
File file1;
for (int i = 0; i < files.length; i++)
{
if (files[i].isFile())
{
file1 = new File(file.getAbsolutePath() + "//" + files[i].getName());
try
{
file1.createNewFile();
fis = new FileInputStream(files[i]);
fos = new FileOutputStream(file1);
while (true)
{
fread = fis.read();
if (fread == -1)
{
break;
}
fos.write(fread);
}
} catch (FileNotFoundException e) {} catch (IOException e) {}
}
else
{
func(files[i], file.getAbsolutePath());
}
}
}
}
现在复制大文件需要很长时间。
有什么方法可以更快地执行复制操作?
提前感谢任何建议。
最佳答案
如果您可以使用 Java 7 或更高版本:java.nio.file.Files#copy .
如果您受困于旧版 Java:java.nio.channels.FileChannel#transferTo
从文件流中获取 FileChannel
实例的基本示例:
public void copy( FileInputStream fis, FileOutputStream fos ) throws IOException {
FileChannel fic = fis.getChannel();
FileChannel foc = fos.getChannel();
long position = 0;
long remaining = fic.size();
while ( remaining > 0 ) {
long transferred = fic.transferTo( position, remaining, foc );
position += transferred;
remaining -= transferred;
}
}
关于java - 加快在java中的复制,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22706136/