JAVA EE: Java Tutorial : Java IO (Java File - How to copy directory

Wednesday 23 November 2016

Java Tutorial : Java IO (Java File - How to copy directory - recursive copy)

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https://www.youtube.com/watch?v=cUxoLssRyAE&list=UUhwKlOVR041tngjerWxVccw

FileDemo.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileDemo
{
    public static void main(String[] args) throws IOException
    {
        File srcDir = new File("D:/Work/java");
        File destDir = new File("D:/work/javanew");

        // Make sure srcDir exists
        if (!srcDir.exists())
        {
            System.out.println("Directory does not exist.");
        }
        else
        {
            FileDemo fileDemo = new FileDemo();
            fileDemo.copydir(srcDir, destDir);
            System.out.println("Copied successfully.");
        }

    }

    public void copydir(File src, File dest) throws IOException
    {

        if (src.isDirectory())
        {

            // if directory not exists, create it
            if (!dest.exists())
            {
                dest.mkdir();
                System.out.println("Directory copied from " + src + "  to "
                        + dest);
            }

            // list all the directory contents
            String files[] = src.list();

            for (String fileName : files)
            {
                // construct the src and dest file structure
                File srcFile = new File(src, fileName);
                File destFile = new File(dest, fileName);
                // recursive copy
                copydir(srcFile, destFile);
            }

        }
        else
        {
            // If file, then copy it
            fileCopy(src, dest);
        }
    }

    private void fileCopy(File src, File dest)
            throws FileNotFoundException, IOException
    {

        InputStream in = null;
        OutputStream out = null;

        try
        {
            // If file, then copy it
            in = new FileInputStream(src);
            out = new FileOutputStream(dest);

            byte[] buffer = new byte[1024];

            int length;
            // Copy the file content in bytes
            while ((length = in.read(buffer)) > 0)
            {
                out.write(buffer, 0, length);
            }

        }
        finally
        {
            if (in != null)
            {
                in.close();
            }
            if (out != null)
            {
                out.close();
            }
        }
        System.out.println("File copied from " + src + " to " + dest);
    }
}

Output

Directory copied from D:\Work\java  to D:\work\javanew
File copied from D:\Work\java\index.html to D:\work\javanew\index.html
----
----
File copied from D:\Work\java\websocket-deprecated\index.html to D:\work\javanew\websocket-deprecated\index.html
File copied from D:\Work\java\websocket-deprecated\snake.html to D:\work\javanew\websocket-deprecated\snake.html
Copied successfully.