JavaIO字节流复制文件

复制单个文件

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyFile {
    public static void main(String[] args) throws IOException {
        long l = System.currentTimeMillis();
        FileInputStream fis = new FileInputStream("D:\\百度云视频\\闪灵.mp4");
        FileOutputStream fos = new FileOutputStream("G:\\桌面\\闪灵.mp4");//文件路径一定要存在

        byte[] bytes = new byte[1024 * 1024];

        int len;
        while ((len = fis.read(bytes)) != -1) {
            fos.write(bytes, 0, len);
        }
        fis.close();
        fos.close();
        long l1 = System.currentTimeMillis();
        System.out.println(l1 - l);
    }
}

复制一个文件夹到另一个文件夹

import java.io.*;

public class CopyFile {
    public static void main(String[] args) throws IOException {
        File srcfile = new File("H:\\javaee");
        File defile = new File("D:\\java", srcfile.getName());//文件夹路径可以不存在
        if (!defile.exists())//如果不存在就创建
            defile.mkdirs();
        File[] files = srcfile.listFiles();
        for (File file : files) {
            if (file.isFile()) {
                File newfile = new File(defile + file.getName());
                InputStream inputStream = new FileInputStream(file);
                OutputStream outputStream = new FileOutputStream(newfile);
                byte[] bytes = new byte[1024 * 1024];//如果1024*1024太慢,可以改1024*8或者1024*1000试一下
                int len;
                while ((len = inputStream.read(bytes)) != -1) {
                    outputStream.write(bytes, 0, len);
                }
                inputStream.close();
                outputStream.close();
            }
        }
    }
}

文件夹复制完整版

import java.io.*;

public class CopyFiles {
    public static void main(String[] args) {
        long l = System.currentTimeMillis();
        File srcFile = new File("G:\\桌面\\SmartEducation\\");
        File destFile = new File("D:\\lianxi1\\");
        copyFiles(srcFile, destFile);
        long e = System.currentTimeMillis();
        System.out.println("复制完成,共耗时" + (e - l) / 1000 + "秒");
    }

    public static void copyFiles(File src, File dest) {
        String name = src.getName();
        File newFile = new File(dest, name);
        System.out.println(newFile);
        if (!newFile.exists()) {
            boolean mkdirs = newFile.mkdirs();
            if (mkdirs) {
                System.out.println("文件夹创建成功！");
            }
        }
        File[] files = src.listFiles();
        for (File file : files) {
            if (file.isFile()) {
                File defile = new File(newFile, file.getName());
                System.out.println(defile);
                InputStream inputStream = null;
                OutputStream outputStream = null;
                try {
                    inputStream = new FileInputStream(file);
                    outputStream = new FileOutputStream(defile);
                    byte[] bytes = new byte[1024 * 1024];
                    int len;
                    while ((len = inputStream.read(bytes)) != -1) {
                        outputStream.write(bytes, 0, len);
                    }
                    System.out.println("文件写入成功");
                } catch (IOException e) {
                    //e.printStackTrace();
                    System.out.println("文件写入失败");
                } finally {
                    try {
                        inputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    try {
                        outputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            } else {
                copyFiles(file, newFile);
            }
        }
    }
}