Java 文件复制到非空目标文件夹

Question

I'm having real difficulties figuring out how this needs to be coded without using FileUtils import. I have found thousands of tutorials on how to move files to empty folders, that's easy. The difficulty is finding out how Java can move files to directories that already have files in the folder. As I understand it the REPLACE_EXISTING parameter means it will overwrite identical file names if detected in the destination directory, but the directory doesn't have a file with a matching name of the file I'm attempting to copy/move. What am I missing? How can I make this happen?

java.nio.file.DirectoryNotEmptyException occuring.

enter code here

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;



public class Move {
 static File source = new File("sourcefolderhere");
static File destination = new File("destfolderhere");


public static void move(File src, File dest) throws IOException {
    Files.move(src.toPath().toAbsolutePath(), dest.toPath().toAbsolutePath(),
            StandardCopyOption.REPLACE_EXISTING);         
}

public static void main(String[] args) throws IOException { 

try {       
    if(source.isDirectory() && destination.isDirectory()) {         
        File[] content = source.listFiles();           
        for(int i = 0; i < content.length; i++) {
            System.out.println(content[i]);  
            move(source, destination);                
        }            
    }
    else if (!destination.isDirectory()){ 
        System.out.println("create folder here");
        destination.mkdir();
        File[] content = source.listFiles();           
        for(int i = 0; i < content.length; i++) {
            move(source, destination);              
        }
    }
 }
 catch(Exception ex) {   System.out.println(ex);    
 }
 finally {
    
 }
 }
 }

Answer 1

I tried the code in IDE File.move method with parameter StandardCopyOption.REPLACE_EXISTING works only if you have file in the destination folder. otherwise use File.move the normal way. I have also modified your code a little just to avoid code duplication.

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.Arrays;

public class Move {
    static File source = new File("sourcefolderhere");
    static File destination = new File("destfolderhere");

    public static void move(File src, File dest) throws IOException {
        System.out.println(src.getName());
        if(isExist(src.getName()))
            Files.move(src.toPath().toAbsolutePath(), Paths.get(destination.getAbsolutePath()+File.separator+src.getName()) , StandardCopyOption.REPLACE_EXISTING);
        else
            Files.move(src.toPath().toAbsolutePath(), Paths.get(destination.getAbsolutePath()+File.separator+src.getName()));
    }
    
    public static boolean isExist(String souceFileName){
        //If you are not using java 8 code
        /*String[] destFiles = destination.list();
        for(String fileName : destFiles){
            if(souceFileName.equals(fileName))
                return true;
        }
        return false;*/
        return Arrays.stream(destination.list())
                .anyMatch(fileName -> fileName.equals(souceFileName));
    }

    public static void main(String[] args) throws IOException {

        try {
            if(!source.isDirectory())
                throw new IllegalArgumentException("Source Folder doesn't Exist");
            if(!destination.exists())
                destination.mkdir();
            if (source.isDirectory() && destination.isDirectory()) {
                File[] content = source.listFiles();
                for (int i = 0; i < content.length; i++) {
                    System.out.println(content[i]);
                    move(content[i], destination);
                }
            }
        } catch (Exception ex) {
            System.out.println(ex);
        } finally {

        }
    }
}```