删除超过x天的文件

Question

如何找出使用java创建文件的时间,因为我希望删除早于某个时间段的文件,目前我正在删除目录中的所有文件,但这并不理想:

public void DeleteFiles() {
    File file = new File("D:/Documents/NetBeansProjects/printing~subversion/fileupload/web/resources/pdf/");
    System.out.println("Called deleteFiles");
    DeleteFiles(file);
    File file2 = new File("D:/Documents/NetBeansProjects/printing~subversion/fileupload/Uploaded/");
    DeleteFilesNonPdf(file2);
}

public void DeleteFiles(File file) {
    System.out.println("Now will search folders and delete files,");
    if (file.isDirectory()) {
        for (File f : file.listFiles()) {
            DeleteFiles(f);
        }
    } else {
        file.delete();
    }
}

以上是我当前的代码,我现在正在尝试添加一个if语句,只删除比一周更早的文件.

编辑:

@ViewScoped
@ManagedBean
public class Delete {

    public void DeleteFiles() {
        File file = new File("D:/Documents/NetBeansProjects/printing~subversion/fileupload/web/resources/pdf/");
        System.out.println("Called deleteFiles");
        DeleteFiles(file);
        File file2 = new File("D:/Documents/NetBeansProjects/printing~subversion/fileupload/Uploaded/");
        DeleteFilesNonPdf(file2);
    }

    public void DeleteFiles(File file) {
        System.out.println("Now will search folders and delete files,");
        if (file.isDirectory()) {
            System.out.println("Date Modified : " + file.lastModified());
            for (File f : file.listFiles()) {
                DeleteFiles(f);
            }
        } else {
            file.delete();
        }
    }

现在添加一个循环.

编辑

我注意到在测试上面的代码时,我得到了最后一次修改:

INFO: Date Modified : 1361635382096

我应该如何编写if循环来说明它是否超过7天,当它是上述格式时删除它？

Answer 1

您可以使用它File.lastModified()来获取文件/目录的上次修改时间.

可以像这样使用:

long diff = new Date().getTime() - file.lastModified();

if (diff > x * 24 * 60 * 60 * 1000) {
    file.delete();
}

删除超过x(一int)天的文件.

Answer 2

Commons IO内置支持使用AgeFileFilter按年龄过滤文件.你DeleteFiles可以看起来像这样:

import java.io.File;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.AgeFileFilter;
import static org.apache.commons.io.filefilter.TrueFileFilter.TRUE;

// a Date defined somewhere for the cutoff date
Date thresholdDate = <the oldest age you want to keep>;

public void DeleteFiles(File file) {
    Iterator<File> filesToDelete =
        FileUtils.iterateFiles(file, new AgeFileFilter(thresholdDate), TRUE);
    for (File aFile : filesToDelete) {
        aFile.delete();
    }
}

更新:要使用编辑中给出的值,请将以下内容定义thresholdDate为:

Date tresholdDate = new Date(1361635382096L);

Answer 3

使用Apache utils可能是最简单的.这是我能提出的最简单的解决方案.

public void deleteOldFiles() {
    Date oldestAllowedFileDate = DateUtils.addDays(new Date(), -3); //minus days from current date
    File targetDir = new File("C:\\TEMP\\archive\\");
    Iterator<File> filesToDelete = FileUtils.iterateFiles(targetDir, new AgeFileFilter(oldestAllowedFileDate), null);
    //if deleting subdirs, replace null above with TrueFileFilter.INSTANCE
    while (filesToDelete.hasNext()) {
        FileUtils.deleteQuietly(filesToDelete.next());
    }  //I don't want an exception if a file is not deleted. Otherwise use filesToDelete.next().delete() in a try/catch
}

Answer 4

Example using Java 8's Time API

LocalDate today = LocalDate.now();
LocalDate eailer = today.minusDays(30);

Date threshold = Date.from(eailer.atStartOfDay(ZoneId.systemDefault()).toInstant());
AgeFileFilter filter = new AgeFileFilter(threshold);

File path = new File("...");
File[] oldFolders = FileFilterUtils.filter(filter, path);

for (File folder : oldFolders) {
    System.out.println(folder);
}

Answer 5

使用Lambda（Java 8+）

非递归选项，用于删除当前文件夹中超过N天的所有文件（忽略子文件夹）：

public static void deleteFilesOlderThanNDays(int days, String dirPath) throws IOException {
    long cutOff = System.currentTimeMillis() - (days * 24 * 60 * 60 * 1000);
    Files.list(Paths.get(dirPath))
    .filter(path -> {
        try {
            return Files.isRegularFile(path) && Files.getLastModifiedTime(path).to(TimeUnit.MILLISECONDS) < cutOff;
        } catch (IOException ex) {
            // log here and move on
            return false;
        }
    })
    .forEach(path -> {
        try {
            Files.delete(path);
        } catch (IOException ex) {
            // log here and move on
        }
    });
}

递归选项，它遍历子文件夹并删除所有早于N天的文件：

public static void recursiveDeleteFilesOlderThanNDays(int days, String dirPath) throws IOException {
    long cutOff = System.currentTimeMillis() - (days * 24 * 60 * 60 * 1000);
    Files.list(Paths.get(dirPath))
    .forEach(path -> {
        if (Files.isDirectory(path)) {
            try {
                recursiveDeleteFilesOlderThanNDays(days, path.toString());
            } catch (IOException e) {
                // log here and move on
            }
        } else {
            try {
                if (Files.getLastModifiedTime(path).to(TimeUnit.MILLISECONDS) < cutOff) {
                    Files.delete(path);
                }
            } catch (IOException ex) {
                // log here and move on
            }
        }
    });
}

Answer 6

对于使用NIO文件流和JSR-310的JDK 8解决方案

long cut = LocalDateTime.now().minusWeeks(1).toEpochSecond(ZoneOffset.UTC);
Path path = Paths.get("/path/to/delete");
Files.list(path)
        .filter(n -> {
            try {
                return Files.getLastModifiedTime(n)
                        .to(TimeUnit.SECONDS) < cut;
            } catch (IOException ex) {
                //handle exception
                return false;
            }
        })
        .forEach(n -> {
            try {
                Files.delete(n);
            } catch (IOException ex) {
                //handle exception
            }
        });

这里很糟糕的是需要处理每个lambda中的异常.API UncheckedIOException对每个IO方法都有重载会很棒.帮助者可以这样写:

public static void main(String[] args) throws IOException {
    long cut = LocalDateTime.now().minusWeeks(1).toEpochSecond(ZoneOffset.UTC);
    Path path = Paths.get("/path/to/delete");
    Files.list(path)
            .filter(n -> Files2.getLastModifiedTimeUnchecked(n)
                    .to(TimeUnit.SECONDS) < cut)
            .forEach(n -> {
                System.out.println(n);
                Files2.delete(n, (t, u)
                              -> System.err.format("Couldn't delete %s%n",
                                                   t, u.getMessage())
                );
            });
}


private static final class Files2 {

    public static FileTime getLastModifiedTimeUnchecked(Path path,
            LinkOption... options)
            throws UncheckedIOException {
        try {
            return Files.getLastModifiedTime(path, options);
        } catch (IOException ex) {
            throw new UncheckedIOException(ex);
        }
    }

    public static void delete(Path path, BiConsumer<Path, Exception> e) {
        try {
            Files.delete(path);
        } catch (IOException ex) {
            e.accept(path, ex);
        }
    }

}

Answer 7

这是使用Time API的Java 8版本。它已在我们的项目中经过测试和使用：

    public static int deleteFiles(final Path destination,
        final Integer daysToKeep) throws IOException {

    final Instant retentionFilePeriod = ZonedDateTime.now()
            .minusDays(daysToKeep).toInstant();

    final AtomicInteger countDeletedFiles = new AtomicInteger();
    Files.find(destination, 1,
            (path, basicFileAttrs) -> basicFileAttrs.lastModifiedTime()
                    .toInstant().isBefore(retentionFilePeriod))
            .forEach(fileToDelete -> {
                try {
                    if (!Files.isDirectory(fileToDelete)) {
                        Files.delete(fileToDelete);
                        countDeletedFiles.incrementAndGet();
                    }
                } catch (IOException e) {
                    throw new UncheckedIOException(e);
                }
            });

    return countDeletedFiles.get();
}

Answer 8

JavaSE 规范解决方案。删除超过expirationPeriod几天的文件。

private void cleanUpOldFiles(String folderPath, int expirationPeriod) {
    File targetDir = new File(folderPath);
    if (!targetDir.exists()) {
        throw new RuntimeException(String.format("Log files directory '%s' " +
                "does not exist in the environment", folderPath));
    }

    File[] files = targetDir.listFiles();
    for (File file : files) {
        long diff = new Date().getTime() - file.lastModified();

        // Granularity = DAYS;
        long desiredLifespan = TimeUnit.DAYS.toMillis(expirationPeriod); 

        if (diff > desiredLifespan) {
            file.delete();
        }
    }
}

例如 - 要删除文件夹“/sftp/logs”中超过 30 天的所有文件，请调用：

cleanUpOldFiles("/sftp/logs", 30);