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
在Java 7中,我们终于可以通过可靠的符号链接检测来做到这一点。(我不认为Apache的commons-io现在有可靠的符号链接检测,因为它不处理Windows上用mklink创建的链接。)
出于历史原因,这里有一个java 7之前的答案,它遵循符号链接。
void delete(File f) throws IOException {
if (f.isDirectory()) {
for (File c : f.listFiles())
delete(c);
}
if (!f.delete())
throw new FileNotFoundException("Failed to delete file: " + f);
}
其他回答
你可以用:
org . apache commons。我deleteQuietly (destFile FileUtils);
删除文件,从不抛出异常。如果file是目录,请删除该目录及其所有子目录。 File.delete()和这个方法的区别是: 待删除的目录不需要为空目录。 当无法删除文件或目录时,不会抛出异常。
番石榴21.0及以上版本
有一个void deleterecursive (Path Path, RecursiveDeleteOption…)options)会抛出从Guava 21.0开始可用的MoreFiles类的IOException静态方法。
请参阅Javadoc文档:
public static void deleteRecursively(Path path, RecursiveDeleteOption... options) throws IOException Deletes the file or directory at the given path recursively. Deletes symbolic links, not their targets (subject to the caveat below). If an I/O exception occurs attempting to read, open or delete any file under the given directory, this method skips that file and continues. All such exceptions are collected and, after attempting to delete all files, an IOException is thrown containing those exceptions as suppressed exceptions.
使用符号链接和上面的代码失败的两种方式…也不知道怎么解决。
方法# 1
运行这个来创建一个测试:
echo test > testfile
mkdir dirtodelete
ln -s badlink dirtodelete/badlinktodelete
下面你可以看到你的测试文件和测试目录:
$ ls testfile dirtodelete
testfile
dirtodelete:
linktodelete
然后运行common -io deleteDirectory()。它崩溃,说文件没有找到。不知道其他例子是怎么做的。Linux的rm命令会简单地删除链接,目录上的rm -r也会删除链接。
Exception in thread "main" java.io.FileNotFoundException: File does not exist: /tmp/dirtodelete/linktodelete
方法# 2
运行这个来创建一个测试:
mkdir testdir
echo test > testdir/testfile
mkdir dirtodelete
ln -s ../testdir dirtodelete/dirlinktodelete
下面你可以看到你的测试文件和测试目录:
$ ls dirtodelete testdir
dirtodelete:
dirlinktodelete
testdir:
testfile
然后运行common -io deleteDirectory()或人们发布的示例代码。它不仅会删除目录,还会删除位于被删除目录之外的testfile。(它隐式地取消对目录的引用,并删除内容)。Rm -r只会删除链接。你需要使用类似这样的方法删除被解引用的文件:"find -L dirtodelete -type f -exec rm {} \;"
$ ls dirtodelete testdir
ls: cannot access dirtodelete: No such file or directory
testdir:
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);
}
}
public void deleteRecursive(File path){
File[] c = path.listFiles();
System.out.println("Cleaning out folder:" + path.toString());
for (File file : c){
if (file.isDirectory()){
System.out.println("Deleting file:" + file.toString());
deleteRecursive(file);
file.delete();
} else {
file.delete();
}
}
path.delete();
}