File.deleteRecursively() - how to delete the folder's content and not the folder itself-CodePudding

I have a folder that contains picture files. I use File.deleteRecursively() to delete the files, and it works perfectly, but I must delete the content, not the 'Pictures' folder itself. How can that be done?

CodePudding user response：

This should work

private static void deleteDirContent(String path){
    File f = new File(path);
    File[] allFiles = f.listFiles();
    if(allFiles == null)
        return;
    for (File f2 :
            allFiles) {
        if(f2.isFile()) {
            if (f2.delete()) {
                // this means file is deleted, everything is good
            } else {
                // was unable to delete the file, handle accordingly.
            }
        }
        else{
            f2.deleteRecursively();
        }
    }
}

Make sure you have the right permissions of course. For some reason I don't have deleteRecursively function, if it's Kotlin implementation then for Java you can add this function:

private static void deleteDirContentWithDir(String path){
    File f = new File(path);
    File[] allFiles = f.listFiles();
    if(allFiles == null)
        return;
    for (File f2 :
            allFiles) {
        if(f2.isFile()) {
            if (f2.delete()) {
                // this means file is deleted, everything is good
            } else {
                // was unable to delete the file, handle accordingly.
            }
        }
        else{
            deleteDirContentWithDir(f2.getAbsolutePath());
        }
    }
    f.delete();
}

This will delete the dir content. In general, you can combine them to a single function:

private static void deleteDirContent(String path, boolean delWithDir){
    File f = new File(path);
    File[] allFiles = f.listFiles();
    if(allFiles == null)
        return;
    for (File f2 :
            allFiles) {
        if(f2.isFile()) {
            if (f2.delete()) {
                // this means file is deleted, everything is good
            } else {
                // was unable to delete the file, handle accordingly.
            }
        }
        else{
            deleteDirContent(f2.getAbsolutePath(), true);
        }
    }
    if(delWithDir)
        f.delete();
}

This basically says, delete a directory content, including directories that might have content and lets you decide if you want to delete the directory it self using the boolean parameter

CodePudding user response：

If you can use Kotlin version 1.8 or later, there is a new extension function on java.nio.files.Path which is preferable to File.deleteRecursively because it gives you more information (through exceptions) when a file cannot be deleted. It is currently "experimental":

import kotlin.io.path.*

@OptIn(ExperimentalPathApi::class)
fun deleteDirectoryContents(dir: String) {
    Path(dir).forEachDirectoryEntry { it.deleteRecursively() }
}