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);
}

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);
    }
}

您应该查看Apache的commons-io。它有一个FileUtils类，可以做你想做的事情。

FileUtils.deleteDirectory(new File("directory"));

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);
}