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Get a unique file id in Windows with Java?

I am looking for a way to get a unique file identifier in a Java application and stumbled upon this:

Unique file identifier in windows

Now I tried the answer provided by Ashley Henderson himself (the one who asked the question), and it worked fine in C #. But I need to do this in Java so that the application runs on different platforms.

Is there a way to port this to Java or go to the same identifier in a different way?

EDIT:

I worked almost now using the eee solution, only I need it in the library, and when I compile it as a library, I get an error message, although everything works fine in the test application, everything is included. But with a separate library that I'm trying to import (without compiler errors), I get this runtime error:

debug: Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/jna/Structure at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) at winfileid.FileId.getFileId(FileId.java:37) at testfileid.TestFileId.main(TestFileId.java:19) Caused by: java.lang.ClassNotFoundException: com.sun.jna.Structure at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) ... 14 more Java Result: 1 BUILD SUCCESSFUL (total time: 0 seconds)

I included jna.jar and platform.jar in the library when I compiled it ... Please note that I am very new to Java, but what am I doing wrong?

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3 answers

Using JNA version 3.3.0:

Kernel32.INSTANCE.GetFileInformationByHandle Test case:

 package win.test; import com.sun.jna.platform.win32.Kernel32; import com.sun.jna.platform.win32.WinBase; import com.sun.jna.platform.win32.WinBase.FILETIME; import com.sun.jna.platform.win32.WinNT.HANDLE; import win.test.Kernel32.BY_HANDLE_FILE_INFORMATION; public class FileTest { /** * @param args */ public static void main(String[] args) { //http://msdn.microsoft.com/en-us/library/windows/desktop/aa363858%28v=vs.85%29.aspx final int FILE_SHARE_READ = (0x00000001); //final int FILE_SHARE_WRITE = (0x00000002); //final int FILE_SHARE_DELETE = (0x00000004); final int OPEN_EXISTING = (3); final int GENERIC_READ = (0x80000000); //final int GENERIC_WRITE = (0x40000000); //final int FILE_FLAG_NO_BUFFERING = (0x20000000); //final int FILE_FLAG_WRITE_THROUGH = (0x80000000); //final int FILE_READ_ATTRIBUTES = (0x0080); //final int FILE_WRITE_ATTRIBUTES = (0x0100); //final int ERROR_INSUFFICIENT_BUFFER = (122); final int FILE_ATTRIBUTE_ARCHIVE = (0x20); WinBase.SECURITY_ATTRIBUTES attr = null; BY_HANDLE_FILE_INFORMATION lpFileInformation = new BY_HANDLE_FILE_INFORMATION(); HANDLE hFile = null; hFile = Kernel32.INSTANCE.CreateFile(args[0], GENERIC_READ, FILE_SHARE_READ, attr, OPEN_EXISTING, FILE_ATTRIBUTE_ARCHIVE, null); System.out.println("CreateFile last error:" + Kernel32.INSTANCE.GetLastError()); //if (hFile. != -1) { win.test.Kernel32.INSTANCE.GetFileInformationByHandle(hFile, lpFileInformation); System.out.println("CREATION TIME: " + FILETIME.filetimeToDate(lpFileInformation.ftCreationTime.dwHighDateTime, lpFileInformation.ftCreationTime.dwLowDateTime)); System.out.println("VOLUME SERIAL NO.: " + Integer.toHexString(lpFileInformation.dwVolumeSerialNumber.intValue())); System.out.println("FILE INDEX HIGH: " + lpFileInformation.nFileIndexHigh); System.out.println("FILE INDEX LOW: " + lpFileInformation.nFileIndexLow); System.out.println("GetFileInformationByHandle last error:" + Kernel32.INSTANCE.GetLastError()); } Kernel32.INSTANCE.CloseHandle(hFile); System.out.println("CloseHandle last error:" + Kernel32.INSTANCE.GetLastError()); } }

Output Example:

 CreateFile last error:0 CREATION TIME: Tue Nov 29 22:24:04 SGT 2011 VOLUME SERIAL NO.: 900c0655 FILE INDEX HIGH: 1769472 FILE INDEX LOW: 286306 GetFileInformationByHandle last error:0 CloseHandle last error:0

Kernel32 JNA Instance Class:

 package win.test; import java.util.HashMap; import java.util.Map; import com.sun.jna.Library; import com.sun.jna.Native; import com.sun.jna.Pointer; import com.sun.jna.Structure; import com.sun.jna.WString; import com.sun.jna.platform.win32.WinBase.FILETIME; import com.sun.jna.platform.win32.WinDef.DWORD; import com.sun.jna.platform.win32.WinNT.HANDLE; import com.sun.jna.win32.StdCallLibrary; import com.sun.jna.win32.W32APIFunctionMapper; import com.sun.jna.win32.W32APITypeMapper; public interface Kernel32 extends StdCallLibrary { final static Map<String, Object> WIN32API_OPTIONS = new HashMap<String, Object>() { private static final long serialVersionUID = 1L; { put(Library.OPTION_FUNCTION_MAPPER, W32APIFunctionMapper.UNICODE); put(Library.OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE); } }; public Kernel32 INSTANCE = (Kernel32) Native.loadLibrary("Kernel32", Kernel32.class, WIN32API_OPTIONS); public int GetLastError(); /** typedef struct _BY_HANDLE_FILE_INFORMATION { DWORD dwFileAttributes; FILETIME ftCreationTime; FILETIME ftLastAccessTime; FILETIME ftLastWriteTime; DWORD dwVolumeSerialNumber; DWORD nFileSizeHigh; DWORD nFileSizeLow; DWORD nNumberOfLinks; DWORD nFileIndexHigh; DWORD nFileIndexLow; } BY_HANDLE_FILE_INFORMATION, *PBY_HANDLE_FILE_INFORMATION; */ public class BY_HANDLE_FILE_INFORMATION extends Structure { public DWORD dwFileAttributes; public FILETIME ftCreationTime; public FILETIME ftLastAccessTime; public FILETIME ftLastWriteTime; public DWORD dwVolumeSerialNumber; public DWORD nFileSizeHigh; public DWORD nFileSizeLow; public DWORD nNumberOfLinks; public DWORD nFileIndexHigh; public DWORD nFileIndexLow; public static class ByReference extends BY_HANDLE_FILE_INFORMATION implements Structure.ByReference { }; public static class ByValue extends BY_HANDLE_FILE_INFORMATION implements Structure.ByValue { }; }; /** BOOL WINAPI GetFileInformationByHandle( __in HANDLE hFile, __out LPBY_HANDLE_FILE_INFORMATION lpFileInformation ); */ boolean GetFileInformationByHandle( HANDLE hFile, BY_HANDLE_FILE_INFORMATION lpFileInformation ); }
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In Java, you will need to compile JNI, native C, for both Windows (using C # code) and Unix / Linux (using an inode file). Honestly, I do not think it is very safe.

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Can you use the file path as a unique identifier ?!

The full path to the file is quite unique ...

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Source: https://habr.com/ru/post/902633/

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