在Java中是否有一种方法可以递归地删除整个目录?
在正常情况下,可以删除空目录。 然而,当涉及到删除包含内容的整个目录时,就不再那么简单了。
如何在Java中删除包含内容的整个目录?
在Java中是否有一种方法可以递归地删除整个目录?
在正常情况下,可以删除空目录。 然而,当涉及到删除包含内容的整个目录时,就不再那么简单了。
如何在Java中删除包含内容的整个目录?
当前回答
一行程序解决方案(Java8),递归删除所有文件和目录,包括起始目录:
try (var dirStream = Files.walk(Paths.get("c:/dir_to_delete/"))) {
dirStream
.map(Path::toFile)
.sorted(Comparator.reverseOrder())
.forEach(File::delete);
}
我们使用一个颠倒顺序的比较器,否则File::delete将不能删除可能非空的目录。所以,如果你想保留目录,只删除文件,只需在sorted()中删除比较器或完全删除排序,并添加文件过滤器:
try (var dirStream = Files.walk(Paths.get("c:/dir_to_delete/"))) {
dirStream
.filter(Files::isRegularFile)
.map(Path::toFile)
.forEach(File::delete);
}
其他回答
在遗留项目中,我需要创建本地Java代码。我创建了类似于Paulitex代码的代码。看到:
public class FileHelper {
public static boolean delete(File fileOrFolder) {
boolean result = true;
if(fileOrFolder.isDirectory()) {
for (File file : fileOrFolder.listFiles()) {
result = result && delete(file);
}
}
result = result && fileOrFolder.delete();
return result;
}
}
单元测试:
public class FileHelperTest {
@Before
public void setup() throws IOException {
new File("FOLDER_TO_DELETE/SUBFOLDER").mkdirs();
new File("FOLDER_TO_DELETE/SUBFOLDER_TWO").mkdirs();
new File("FOLDER_TO_DELETE/SUBFOLDER_TWO/TEST_FILE.txt").createNewFile();
}
@Test
public void deleteFolderWithFiles() {
File folderToDelete = new File("FOLDER_TO_DELETE");
Assert.assertTrue(FileHelper.delete(folderToDelete));
Assert.assertFalse(new File("FOLDER_TO_DELETE").exists());
}
}
这是一个接受命令行参数的基本main方法,您可能需要附加自己的错误检查或将其塑造为您认为合适的方式。
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
public class DeleteFiles {
/**
* @param intitial arguments take in a source to read from and a
* destination to read to
*/
public static void main(String[] args)
throws FileNotFoundException,IOException {
File src = new File(args[0]);
if (!src.exists() ) {
System.out.println("FAILURE!");
}else{
// Gathers files in directory
File[] a = src.listFiles();
for (int i = 0; i < a.length; i++) {
//Sends files to recursive deletion method
fileDelete(a[i]);
}
// Deletes original source folder
src.delete();
System.out.println("Success!");
}
}
/**
* @param srcFile Source file to examine
* @throws FileNotFoundException if File not found
* @throws IOException if File not found
*/
private static void fileDelete(File srcFile)
throws FileNotFoundException, IOException {
// Checks if file is a directory
if (srcFile.isDirectory()) {
//Gathers files in directory
File[] b = srcFile.listFiles();
for (int i = 0; i < b.length; i++) {
//Recursively deletes all files and sub-directories
fileDelete(b[i]);
}
// Deletes original sub-directory file
srcFile.delete();
} else {
srcFile.delete();
}
}
}
我希望这对你有所帮助!
一个有堆栈且没有递归方法的解决方案:
File dir = new File("/path/to/dir");
File[] currList;
Stack<File> stack = new Stack<File>();
stack.push(dir);
while (! stack.isEmpty()) {
if (stack.lastElement().isDirectory()) {
currList = stack.lastElement().listFiles();
if (currList.length > 0) {
for (File curr: currList) {
stack.push(curr);
}
} else {
stack.pop().delete();
}
} else {
stack.pop().delete();
}
}
虽然可以使用file.delete()轻松删除文件,但要删除的目录必须为空。使用递归可以很容易地做到这一点。例如:
public static void clearFolders(String[] args) {
for(String st : args){
File folder = new File(st);
if (folder.isDirectory()) {
File[] files = folder.listFiles();
if(files!=null) {
for(File f: files) {
if (f.isDirectory()){
clearFolders(new String[]{f.getAbsolutePath()});
f.delete();
} else {
f.delete();
}
}
}
}
}
}
为了更安全的使用,我编写了有3个安全标准的程序。
package ch.ethz.idsc.queuey.util;
import java.io.File;
import java.io.IOException;
/** recursive file/directory deletion
*
* safety from erroneous use is enhanced by three criteria
* 1) checking the depth of the directory tree T to be deleted
* against a permitted upper bound "max_depth"
* 2) checking the number of files to be deleted #F
* against a permitted upper bound "max_count"
* 3) if deletion of a file or directory fails, the process aborts */
public final class FileDelete {
/** Example: The command
* FileDelete.of(new File("/user/name/myapp/recordings/log20171024"), 2, 1000);
* deletes given directory with sub directories of depth of at most 2,
* and max number of total files less than 1000. No files are deleted
* if directory tree exceeds 2, or total of files exceed 1000.
*
* abort criteria are described at top of class
*
* @param file
* @param max_depth
* @param max_count
* @return
* @throws Exception if criteria are not met */
public static FileDelete of(File file, int max_depth, int max_count) throws IOException {
return new FileDelete(file, max_depth, max_count);
}
// ---
private final File root;
private final int max_depth;
private int removed = 0;
/** @param root file or a directory. If root is a file, the file will be deleted.
* If root is a directory, the directory tree will be deleted.
* @param max_depth of directory visitor
* @param max_count of files to delete
* @throws IOException */
private FileDelete(final File root, final int max_depth, final int max_count) throws IOException {
this.root = root;
this.max_depth = max_depth;
// ---
final int count = visitRecursively(root, 0, false);
if (count <= max_count) // abort criteria 2)
visitRecursively(root, 0, true);
else
throw new IOException("more files to be deleted than allowed (" + max_count + "<=" + count + ") in " + root);
}
private int visitRecursively(final File file, final int depth, final boolean delete) throws IOException {
if (max_depth < depth) // enforce depth limit, abort criteria 1)
throw new IOException("directory tree exceeds permitted depth");
// ---
int count = 0;
if (file.isDirectory()) // if file is a directory, recur
for (File entry : file.listFiles())
count += visitRecursively(entry, depth + 1, delete);
++count; // count file as visited
if (delete) {
final boolean deleted = file.delete();
if (!deleted) // abort criteria 3)
throw new IOException("cannot delete " + file.getAbsolutePath());
++removed;
}
return count;
}
public int deletedCount() {
return removed;
}
public void printNotification() {
int count = deletedCount();
if (0 < count)
System.out.println("deleted " + count + " file(s) in " + root);
}
}