关于Windows：如何使用Java发现文件的创建时间？

How to discover a File's creation time with Java?

是否有一种简便的方法来使用Java发现文件的创建时间？ File类仅具有一种获取"上次修改"时间的方法。根据我在Google上发现的一些资源，File类不提供getCreationTime()方法，因为并非所有文件系统都支持创建时间的想法。

我发现唯一可行的解??决方案是卷入命令行并执行" dir"命令，该命令看起来像输出文件的创建时间。我想这可行，我只需要支持Windows，但是我似乎很容易出错。

是否有任何第三方图书馆提供我所需的信息？

更新：最后，我认为购买第三方库对我来说不值得，但是它们的API看起来确实不错，因此对于任何有此问题的人来说，它都是一个不错的选择。

随着Java 7的发布，有一种内置的方法可以做到这一点：

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Path path = Paths.get("path/to/file");
BasicFileAttributes attributes = Files.readAttributes(path, BasicFileAttributes.class);
FileTime creationTime = attributes.creationTime();

请注意，并非所有操作系统都提供此信息。我相信在这些情况下，这会返回mtime，这是最后修改的时间。

Windows确实提供了创建时间。

几天前，我写了一个小测试班，希望它能对您有所帮助：

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// Get/Set windows file CreationTime/LastWriteTime/LastAccessTime
// Test with jna-3.2.7
// [http://maclife.net/wiki/index.php?title=Java_get_and_set_windows_system_file_creation_time_via_JNA_(Java_Native_Access)][1]

import java.io.*;
import java.nio.*;
import java.util.Date;

// Java Native Access library: jna.dev.java.net
import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.*;
import com.sun.jna.platform.win32.*;

public class WindowsFileTime
{
public static final int GENERIC_READ = 0x80000000;
//public static final int GENERIC_WRITE = 0x40000000; // defined in com.sun.jna.platform.win32.WinNT
public static final int GENERIC_EXECUTE = 0x20000000;
public static final int GENERIC_ALL = 0x10000000;

// defined in com.sun.jna.platform.win32.WinNT
//public static final int CREATE_NEW = 1;
//public static final int CREATE_ALWAYS = 2;
//public static final int OPEN_EXISTING = 3;
//public static final int OPEN_ALWAYS = 4;
//public static final int TRUNCATE_EXISTING = 5;

public interface MoreKernel32 extends Kernel32
{
static final MoreKernel32 instance = (MoreKernel32)Native.loadLibrary ("kernel32", MoreKernel32.class, W32APIOptions.DEFAULT_OPTIONS);
boolean GetFileTime (WinNT.HANDLE hFile, WinBase.FILETIME lpCreationTime, WinBase.FILETIME lpLastAccessTime, WinBase.FILETIME lpLastWriteTime);
boolean SetFileTime (WinNT.HANDLE hFile, final WinBase.FILETIME lpCreationTime, final WinBase.FILETIME lpLastAccessTime, final WinBase.FILETIME lpLastWriteTime);
}

static MoreKernel32 win32 = MoreKernel32.instance;
//static Kernel32 _win32 = (Kernel32)win32;

static WinBase.FILETIME _creationTime = new WinBase.FILETIME ();
static WinBase.FILETIME _lastWriteTime = new WinBase.FILETIME ();
static WinBase.FILETIME _lastAccessTime = new WinBase.FILETIME ();

static boolean GetFileTime (String sFileName, Date creationTime, Date lastWriteTime, Date lastAccessTime)
{
WinNT.HANDLE hFile = OpenFile (sFileName, GENERIC_READ); // may be WinNT.GENERIC_READ in future jna version.
if (hFile == WinBase.INVALID_HANDLE_VALUE) return false;

boolean rc = win32.GetFileTime (hFile, _creationTime, _lastAccessTime, _lastWriteTime);
if (rc)
{
if (creationTime != null) creationTime.setTime (_creationTime.toLong());
if (lastAccessTime != null) lastAccessTime.setTime (_lastAccessTime.toLong());
if (lastWriteTime != null) lastWriteTime.setTime (_lastWriteTime.toLong());
}
else
{
int iLastError = win32.GetLastError();
System.out.print ("è?·??–?–?????—?é—′?¤±è′￥???é"?èˉˉ?????" + iLastError +"" + GetWindowsSystemErrorMessage (iLastError));
}
win32.CloseHandle (hFile);
return rc;
}
static boolean SetFileTime (String sFileName, final Date creationTime, final Date lastWriteTime, final Date lastAccessTime)
{
WinNT.HANDLE hFile = OpenFile (sFileName, WinNT.GENERIC_WRITE);
if (hFile == WinBase.INVALID_HANDLE_VALUE) return false;

ConvertDateToFILETIME (creationTime, _creationTime);
ConvertDateToFILETIME (lastWriteTime, _lastWriteTime);
ConvertDateToFILETIME (lastAccessTime, _lastAccessTime);

//System.out.println ("creationTime:" + creationTime);
//System.out.println ("lastWriteTime:" + lastWriteTime);
//System.out.println ("lastAccessTime:" + lastAccessTime);

//System.out.println ("_creationTime:" + _creationTime);
//System.out.println ("_lastWriteTime:" + _lastWriteTime);
//System.out.println ("_lastAccessTime:" + _lastAccessTime);

boolean rc = win32.SetFileTime (hFile, creationTime==null?null:_creationTime, lastAccessTime==null?null:_lastAccessTime, lastWriteTime==null?null:_lastWriteTime);
if (! rc)
{
int iLastError = win32.GetLastError();
System.out.print ("è??????–?????—?é—′?¤±è′￥???é"?èˉˉ?????" + iLastError +"" + GetWindowsSystemErrorMessage (iLastError));
}
win32.CloseHandle (hFile);
return rc;
}
static void ConvertDateToFILETIME (Date date, WinBase.FILETIME ft)
{
if (ft != null)
{
long iFileTime = 0;
if (date != null)
{
iFileTime = WinBase.FILETIME.dateToFileTime (date);
ft.dwHighDateTime = (int)((iFileTime >> 32) & 0xFFFFFFFFL);
ft.dwLowDateTime = (int)(iFileTime & 0xFFFFFFFFL);
}
else
{
ft.dwHighDateTime = 0;
ft.dwLowDateTime = 0;
}
}
}

static WinNT.HANDLE OpenFile (String sFileName, int dwDesiredAccess)
{
WinNT.HANDLE hFile = win32.CreateFile (
sFileName,
dwDesiredAccess,
0,
null,
WinNT.OPEN_EXISTING,
0,
null
);
if (hFile == WinBase.INVALID_HANDLE_VALUE)
{
int iLastError = win32.GetLastError();
System.out.print (" ?‰"??€?–?????¤±è′￥???é"?èˉˉ?????" + iLastError +"" + GetWindowsSystemErrorMessage (iLastError));
}
return hFile;
}
static String GetWindowsSystemErrorMessage (int iError)
{
char[] buf = new char[255];
CharBuffer bb = CharBuffer.wrap (buf);
//bb.clear ();
//PointerByReference pMsgBuf = new PointerByReference ();
int iChar = win32.FormatMessage (
WinBase.FORMAT_MESSAGE_FROM_SYSTEM
//| WinBase.FORMAT_MESSAGE_IGNORE_INSERTS
//|WinBase.FORMAT_MESSAGE_ALLOCATE_BUFFER
,
null,
iError,
0x0804,
bb, buf.length,
//pMsgBuf, 0,
null
);
//for (int i=0; i<iChar; i++)
//{
// System.out.print ("");
// System.out.print (String.format("%02X", buf[i]&0xFFFF));
//}
bb.limit (iChar);
//System.out.print (bb);
//System.out.print (pMsgBuf.getValue().getString(0));
//win32.LocalFree (pMsgBuf.getValue());
return bb.toString ();
}

public static void main (String[] args) throws Exception
{
if (args.length == 0)
{
System.out.println ("è?·??– Windows ????–?????—?é—′????????o?—?é—′?€???€???????"1?—?é—′?€???€???è??é—??—?é—′??‰");
System.out.println ("?"¨?3????");
System.out.println (" java -cp .;..;jna.jar;platform.jar WindowsFileTime [?–???????1] [?–???????2]...");
return;
}

boolean rc;
java.sql.Timestamp ct = new java.sql.Timestamp(0);
java.sql.Timestamp wt = new java.sql.Timestamp(0);
java.sql.Timestamp at = new java.sql.Timestamp(0);

for (String sFileName : args)
{
System.out.println ("?–????" + sFileName);

rc = GetFileTime (sFileName, ct, wt, at);
if (rc)
{
System.out.println (" ?????o?—?é—′???" + ct);
System.out.println (" ????"1?—?é—′???" + wt);
System.out.println (" è??é—??—?é—′???" + at);
}
else
{
//System.out.println ("GetFileTime ?¤±è′￥");
}

//wt.setTime (System.currentTimeMillis());
wt = java.sql.Timestamp.valueOf("2010-07-23 00:00:00");
rc = SetFileTime (sFileName, null, wt, null);
if (rc)
{
System.out.println ("SetFileTime (??€???????"1?—?é—′) ??????");
}
else
{
//System.out.println ("SetFileTime ?¤±è′￥");
}
}
}
}

javaxt-core库包含一个File类，该类可用于检索文件属性，包括创建时间。示例：

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javaxt.io.File file = new javaxt.io.File("/temp/file.txt");
System.out.println("Created:" + file.getCreationTime());
System.out.println("Accessed:" + file.getLastAccessTime());
System.out.println("Modified:" + file.getLastModifiedTime());

适用于Java 1.5及更高版本。

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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class CreateDateInJava {
public static void main(String args[]) {
try {

// get runtime environment and execute child process
Runtime systemShell = Runtime.getRuntime();
BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter filename:");
String fname = (String) br1.readLine();
Process output = systemShell.exec("cmd /c dir "" + fname +"" /tc");

System.out.println(output);
// open reader to get output from process
BufferedReader br = new BufferedReader(new InputStreamReader(output.getInputStream()));

String out ="";
String line = null;

int step = 1;
while ((line = br.readLine()) != null) {
if (step == 6) {
out = line;
}
step++;
}

// display process output
try {
out = out.replaceAll("","");
System.out.println("CreationDate:" + out.substring(0, 10));
System.out.println("CreationTime:" + out.substring(10, 16) +"m");
} catch (StringIndexOutOfBoundsException se) {
System.out.println("File not found");
}
} catch (IOException ioe) {
System.err.println(ioe);
} catch (Throwable t) {
t.printStackTrace();
}
}
}

/**
D:\\Foldername\\Filename.Extension

Ex:
Enter Filename :
D:\\Kamal\\Test.txt
CreationDate: 02/14/2011
CreationTime: 12:59Pm

*/

我一直在自己进行调查，但是我需要一些可以在Windows / * nix平台上运行的工具。

一篇SO帖子中包含指向Posix JNI实现的一些链接。

JNA-POSIX
适用于Java的POSIX

尤其是，JNA-POSIX通过Windows，BSD，Solaris，Linux和OSX的实现来实现获取文件统计信息的方法。

总的来说，它看起来非常有前途，所以我将很快在自己的项目中进行尝试。

我喜欢jGuru上的答案，其中列出了使用JNI获得答案的选项。这可能比脱壳要快，而且您可能会遇到其他情况，例如需要专门针对Windows实施的情况。

此外，如果您需要移植到其他平台，那么也可以移植您的库，并在* ix上让它返回-1，以回答该问题。

这是Java中使用BasicFileAttributes类的一个基本示例：

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Path path = Paths.get("C:\\\\Users\\\\jorgesys\\\\workspaceJava\\\\myfile.txt");
BasicFileAttributes attr;
try {
attr = Files.readAttributes(path, BasicFileAttributes.class);
System.out.println("File creation time:" + attr.creationTime());
} catch (IOException e) {
System.out.println("oops un error!" + e.getMessage());
}