问题
I want to create and delete a directory using Java, but it isn't working.
File index = new File("/home/Work/Indexer1");
if (!index.exists()) {
index.mkdir();
} else {
index.delete();
if (!index.exists()) {
index.mkdir();
}
}
回答1:
Java isn't able to delete folders with data in it. You have to delete all files before deleting the folder.
Use something like:
String[]entries = index.list();
for(String s: entries){
File currentFile = new File(index.getPath(),s);
currentFile.delete();
}
Then you should be able to delete the folder by using index.delete()
Untested!
回答2:
Just a one-liner.
import org.apache.commons.io.FileUtils;
FileUtils.deleteDirectory(new File(destination));
Documentation here
回答3:
This works, and while it looks inefficient to skip the directory test, it's not: the test happens right away in listFiles().
void deleteDir(File file) {
File[] contents = file.listFiles();
if (contents != null) {
for (File f : contents) {
deleteDir(f);
}
}
file.delete();
}
Update, to avoid following symbolic links:
void deleteDir(File file) {
File[] contents = file.listFiles();
if (contents != null) {
for (File f : contents) {
if (! Files.isSymbolicLink(f.toPath())) {
deleteDir(f);
}
}
}
file.delete();
}
回答4:
In JDK 7 you could use Files.walkFileTree() and Files.deleteIfExists() to delete a tree of files.
In JDK 6 one possible way is to use FileUtils.deleteQuietly from Apache Commons which will remove a file, a directory, or a directory with files and sub-directories.
回答5:
I prefer this solution on java 8:
Files.walk(pathToBeDeleted)
.sorted(Comparator.reverseOrder())
.map(Path::toFile)
.forEach(File::delete);
From this site: http://www.baeldung.com/java-delete-directory
回答6:
Using Apache Commons-IO, it is following one-liner:
import org.apache.commons.io.FileUtils;
FileUtils.forceDelete(new File(destination));
This is (slightly) more performant than FileUtils.deleteDirectory.
回答7:
My basic recursive version, working with older versions of JDK:
public static void deleteFile(File element) {
if (element.isDirectory()) {
for (File sub : element.listFiles()) {
deleteFile(sub);
}
}
element.delete();
}
回答8:
This is the best solution for Java 7+:
public static void deleteDirectory(String directoryFilePath) throws IOException
{
Path directory = Paths.get(directoryFilePath);
if (Files.exists(directory))
{
Files.walkFileTree(directory, new SimpleFileVisitor<Path>()
{
@Override
public FileVisitResult visitFile(Path path, BasicFileAttributes basicFileAttributes) throws IOException
{
Files.delete(path);
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult postVisitDirectory(Path directory, IOException ioException) throws IOException
{
Files.delete(directory);
return FileVisitResult.CONTINUE;
}
});
}
}
回答9:
As mentioned, Java isn't able to delete a folder that contains files, so first delete the files and then the folder.
Here's a simple example to do this:
import org.apache.commons.io.FileUtils;
// First, remove files from into the folder
FileUtils.cleanDirectory(folder/path);
// Then, remove the folder
FileUtils.deleteDirectory(folder/path);
Or:
FileUtils.forceDelete(new File(destination));
回答10:
Guava 21+ to the rescue. Use only if there are no symlinks pointing out of the directory to delete.
com.google.common.io.MoreFiles.deleteRecursively(
file.toPath(),
RecursiveDeleteOption.ALLOW_INSECURE
) ;
(This question is well-indexed by Google, so other people usig Guava might be happy to find this answer, even if it is redundant with other answers elsewhere.)
回答11:
I like this solution the most. It does not use 3rd party library, instead it uses NIO2 of Java 7.
/**
* Deletes Folder with all of its content
*
* @param folder path to folder which should be deleted
*/
public static void deleteFolderAndItsContent(final Path folder) throws IOException {
Files.walkFileTree(folder, new SimpleFileVisitor<Path>() {
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
Files.delete(file);
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
if (exc != null) {
throw exc;
}
Files.delete(dir);
return FileVisitResult.CONTINUE;
}
});
}
回答12:
In this
index.delete();
if (!index.exists())
{
index.mkdir();
}
you are calling
if (!index.exists())
{
index.mkdir();
}
after
index.delete();
This means that you are creating the file again after deleting
File.delete() returns a boolean value.So if you want to check then do System.out.println(index.delete()); if you get true then this means that file is deleted
File index = new File("/home/Work/Indexer1");
if (!index.exists())
{
index.mkdir();
}
else{
System.out.println(index.delete());//If you get true then file is deleted
if (!index.exists())
{
index.mkdir();// here you are creating again after deleting the file
}
}
from the comments given below,the updated answer is like this
File f=new File("full_path");//full path like c:/home/ri
if(f.exists())
{
f.delete();
}
else
{
try {
//f.createNewFile();//this will create a file
f.mkdir();//this create a folder
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
回答13:
If you have subfolders, you will find troubles with the Cemron answers. so you should create a method that works like this:
private void deleteTempFile(File tempFile) {
try
{
if(tempFile.isDirectory()){
File[] entries = tempFile.listFiles();
for(File currentFile: entries){
deleteTempFile(currentFile);
}
tempFile.delete();
}else{
tempFile.delete();
}
getLogger().info("DELETED Temporal File: " + tempFile.getPath());
}
catch(Throwable t)
{
getLogger().error("Could not DELETE file: " + tempFile.getPath(), t);
}
}
回答14:
You can use FileUtils.deleteDirectory. JAVA can't delete the non-empty foldres with File.delete().
回答15:
directry cannot simply delete if it has the files so you may need to delete the files inside first and then directory
public class DeleteFileFolder {
public DeleteFileFolder(String path) {
File file = new File(path);
if(file.exists())
{
do{
delete(file);
}while(file.exists());
}else
{
System.out.println("File or Folder not found : "+path);
}
}
private void delete(File file)
{
if(file.isDirectory())
{
String fileList[] = file.list();
if(fileList.length == 0)
{
System.out.println("Deleting Directory : "+file.getPath());
file.delete();
}else
{
int size = fileList.length;
for(int i = 0 ; i < size ; i++)
{
String fileName = fileList[i];
System.out.println("File path : "+file.getPath()+" and name :"+fileName);
String fullPath = file.getPath()+"/"+fileName;
File fileOrFolder = new File(fullPath);
System.out.println("Full Path :"+fileOrFolder.getPath());
delete(fileOrFolder);
}
}
}else
{
System.out.println("Deleting file : "+file.getPath());
file.delete();
}
}
回答16:
You can make recursive call if sub directories exists
import java.io.File;
class DeleteDir {
public static void main(String args[]) {
deleteDirectory(new File(args[0]));
}
static public boolean deleteDirectory(File path) {
if( path.exists() ) {
File[] files = path.listFiles();
for(int i=0; i<files.length; i++) {
if(files[i].isDirectory()) {
deleteDirectory(files[i]);
}
else {
files[i].delete();
}
}
}
return( path.delete() );
}
}
回答17:
we can use the spring-core dependency;
boolean result = FileSystemUtils.deleteRecursively(file);
回答18:
Most of answers (even recent) referencing JDK classes rely on File.delete() but that is a flawed API as the operation may fail silently.
The java.io.File.delete() method documentation states :
Note that the
java.nio.file.Filesclass defines thedeletemethod to throw anIOExceptionwhen a file cannot be deleted. This is useful for error reporting and to diagnose why a file cannot be deleted.
As replacement, you should favor Files.delete(Path p) that throws an IOException with a error message.
The actual code could be written such as :
Path index = Paths.get("/home/Work/Indexer1");
if (!Files.exists(index)) {
index = Files.createDirectories(index);
} else {
Files.walk(index)
.sorted(Comparator.reverseOrder()) // as the file tree is traversed depth-first and that deleted dirs have to be empty
.forEach(t -> {
try {
Files.delete(t);
} catch (IOException e) {
// LOG the exception and potentially stop the processing
}
});
if (!Files.exists(index)) {
index = Files.createDirectories(index);
}
}
回答19:
you can try as follows
File dir = new File("path");
if (dir.isDirectory())
{
dir.delete();
}
If there are sub folders inside your folder you may need to recursively delete them.
回答20:
private void deleteFileOrFolder(File file){
try {
for (File f : file.listFiles()) {
f.delete();
deleteFileOrFolder(f);
}
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
回答21:
import org.apache.commons.io.FileUtils;
List<String> directory = new ArrayList();
directory.add("test-output");
directory.add("Reports/executions");
directory.add("Reports/index.html");
directory.add("Reports/report.properties");
for(int count = 0 ; count < directory.size() ; count ++)
{
String destination = directory.get(count);
deleteDirectory(destination);
}
public void deleteDirectory(String path) {
File file = new File(path);
if(file.isDirectory()){
System.out.println("Deleting Directory :" + path);
try {
FileUtils.deleteDirectory(new File(path)); //deletes the whole folder
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else {
System.out.println("Deleting File :" + path);
//it is a simple file. Proceed for deletion
file.delete();
}
}
Works like a Charm . For both folder and files . Salam :)
回答22:
One more choice is to use Spring's org.springframework.util.FileSystemUtils relevant method which will recursively delete all content of the directory.
File directoryToDelete = new File(<your_directory_path_to_delete>);
FileSystemUtils.deleteRecursively(directoryToDelete);
That will do the job!
回答23:
Remove it from else part
File index = new File("/home/Work/Indexer1");
if (!index.exists())
{
index.mkdir();
System.out.println("Dir Not present. Creating new one!");
}
index.delete();
System.out.println("File deleted successfully");
回答24:
Some of these answers seem unnecessarily long:
if (directory.exists()) {
for (File file : directory.listFiles()) {
file.delete();
}
directory.delete();
}
Works for sub directories too.
回答25:
import java.io.File;
public class Main{
public static void main(String[] args) throws Exception {
deleteDir(new File("c:\\temp"));
}
public static boolean deleteDir(File dir) {
if (dir.isDirectory()) {
String[] children = dir.list();
for (int i = 0; i < children.length; i++) {
boolean success = deleteDir (new File(dir, children[i]));
if (!success) {
return false;
}
}
}
return dir.delete();
System.out.println("The directory is deleted.");
}
}
回答26:
You can use this function
public void delete()
{
File f = new File("E://implementation1/");
File[] files = f.listFiles();
for (File file : files) {
file.delete();
}
}
来源：https://stackoverflow.com/questions/20281835/how-to-delete-a-folder-with-files-using-java