问题
I\'m currently using Win32ShellFolderManager2 and ShellFolder.getLinkLocation to resolve windows shortcuts in Java. Unfortunately, if the Java program is running as a service under Vista, getLinkLocation, this does not work. Specifically, I get an exception stating \"Could not get shell folder ID list\".
Searching the web does turn up mentions of this error message, but always in connection with JFileChooser. I\'m not using JFileChooser, I just need to resolve a .lnk file to its destination.
Does anyone know of a 3rd-party parser for .lnk files written in Java I could use?
I\'ve since found unofficial documentation for the .lnk format here, but I\'d rather not have to do the work if anyone has done it before, since the format is rather scary.
回答1:
Added comments (some explanation as well as credit to each contributor so far),additional check on the file magic, a quick test to see if a given file might be a valid link (without reading all of the bytes), a fix to throw a ParseException with appropriate message instead of ArrayIndexOutOfBoundsException if the file is too small, did some general clean-up.
Source here (if you have any changes, push them right to the GitHub repo/project.
package org.stackoverflowusers.file;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.ParseException;
/**
* Represents a Windows shortcut (typically visible to Java only as a '.lnk' file).
*
* Retrieved 2011-09-23 from http://stackoverflow.com/questions/309495/windows-shortcut-lnk-parser-in-java/672775#672775
* Originally called LnkParser
*
* Written by: (the stack overflow users, obviously!)
* Apache Commons VFS dependency removed by crysxd (why were we using that!?) https://github.com/crysxd
* Headerified, refactored and commented by Code Bling http://stackoverflow.com/users/675721/code-bling
* Network file support added by Stefan Cordes http://stackoverflow.com/users/81330/stefan-cordes
* Adapted by Sam Brightman http://stackoverflow.com/users/2492/sam-brightman
* Based on information in 'The Windows Shortcut File Format' by Jesse Hager <jessehager@iname.com>
* And somewhat based on code from the book 'Swing Hacks: Tips and Tools for Killer GUIs'
* by Joshua Marinacci and Chris Adamson
* ISBN: 0-596-00907-0
* http://www.oreilly.com/catalog/swinghks/
*/
public class WindowsShortcut
{
private boolean isDirectory;
private boolean isLocal;
private String real_file;
/**
* Provides a quick test to see if this could be a valid link !
* If you try to instantiate a new WindowShortcut and the link is not valid,
* Exceptions may be thrown and Exceptions are extremely slow to generate,
* therefore any code needing to loop through several files should first check this.
*
* @param file the potential link
* @return true if may be a link, false otherwise
* @throws IOException if an IOException is thrown while reading from the file
*/
public static boolean isPotentialValidLink(File file) throws IOException {
final int minimum_length = 0x64;
InputStream fis = new FileInputStream(file);
boolean isPotentiallyValid = false;
try {
isPotentiallyValid = file.isFile()
&& file.getName().toLowerCase().endsWith(".lnk")
&& fis.available() >= minimum_length
&& isMagicPresent(getBytes(fis, 32));
} finally {
fis.close();
}
return isPotentiallyValid;
}
public WindowsShortcut(File file) throws IOException, ParseException {
InputStream in = new FileInputStream(file);
try {
parseLink(getBytes(in));
} finally {
in.close();
}
}
/**
* @return the name of the filesystem object pointed to by this shortcut
*/
public String getRealFilename() {
return real_file;
}
/**
* Tests if the shortcut points to a local resource.
* @return true if the 'local' bit is set in this shortcut, false otherwise
*/
public boolean isLocal() {
return isLocal;
}
/**
* Tests if the shortcut points to a directory.
* @return true if the 'directory' bit is set in this shortcut, false otherwise
*/
public boolean isDirectory() {
return isDirectory;
}
/**
* Gets all the bytes from an InputStream
* @param in the InputStream from which to read bytes
* @return array of all the bytes contained in 'in'
* @throws IOException if an IOException is encountered while reading the data from the InputStream
*/
private static byte[] getBytes(InputStream in) throws IOException {
return getBytes(in, null);
}
/**
* Gets up to max bytes from an InputStream
* @param in the InputStream from which to read bytes
* @param max maximum number of bytes to read
* @return array of all the bytes contained in 'in'
* @throws IOException if an IOException is encountered while reading the data from the InputStream
*/
private static byte[] getBytes(InputStream in, Integer max) throws IOException {
// read the entire file into a byte buffer
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buff = new byte[256];
while (max == null || max > 0) {
int n = in.read(buff);
if (n == -1) {
break;
}
bout.write(buff, 0, n);
if (max != null)
max -= n;
}
in.close();
return bout.toByteArray();
}
private static boolean isMagicPresent(byte[] link) {
final int magic = 0x0000004C;
final int magic_offset = 0x00;
return link.length >= 32 && bytesToDword(link, magic_offset) == magic;
}
/**
* Gobbles up link data by parsing it and storing info in member fields
* @param link all the bytes from the .lnk file
*/
private void parseLink(byte[] link) throws ParseException {
try {
if (!isMagicPresent(link))
throw new ParseException("Invalid shortcut; magic is missing", 0);
// get the flags byte
byte flags = link[0x14];
// get the file attributes byte
final int file_atts_offset = 0x18;
byte file_atts = link[file_atts_offset];
byte is_dir_mask = (byte)0x10;
if ((file_atts & is_dir_mask) > 0) {
isDirectory = true;
} else {
isDirectory = false;
}
// if the shell settings are present, skip them
final int shell_offset = 0x4c;
final byte has_shell_mask = (byte)0x01;
int shell_len = 0;
if ((flags & has_shell_mask) > 0) {
// the plus 2 accounts for the length marker itself
shell_len = bytesToWord(link, shell_offset) + 2;
}
// get to the file settings
int file_start = 0x4c + shell_len;
final int file_location_info_flag_offset_offset = 0x08;
int file_location_info_flag = link[file_start + file_location_info_flag_offset_offset];
isLocal = (file_location_info_flag & 2) == 0;
// get the local volume and local system values
//final int localVolumeTable_offset_offset = 0x0C;
final int basename_offset_offset = 0x10;
final int networkVolumeTable_offset_offset = 0x14;
final int finalname_offset_offset = 0x18;
int finalname_offset = link[file_start + finalname_offset_offset] + file_start;
String finalname = getNullDelimitedString(link, finalname_offset);
if (isLocal) {
int basename_offset = link[file_start + basename_offset_offset] + file_start;
String basename = getNullDelimitedString(link, basename_offset);
real_file = basename + finalname;
} else {
int networkVolumeTable_offset = link[file_start + networkVolumeTable_offset_offset] + file_start;
int shareName_offset_offset = 0x08;
int shareName_offset = link[networkVolumeTable_offset + shareName_offset_offset]
+ networkVolumeTable_offset;
String shareName = getNullDelimitedString(link, shareName_offset);
real_file = shareName + "\\" + finalname;
}
} catch (ArrayIndexOutOfBoundsException e) {
throw new ParseException("Could not be parsed, probably not a valid WindowsShortcut", 0);
}
}
private static String getNullDelimitedString(byte[] bytes, int off) {
int len = 0;
// count bytes until the null character (0)
while (true) {
if (bytes[off + len] == 0) {
break;
}
len++;
}
return new String(bytes, off, len);
}
/*
* convert two bytes into a short note, this is little endian because it's
* for an Intel only OS.
*/
private static int bytesToWord(byte[] bytes, int off) {
return ((bytes[off + 1] & 0xff) << 8) | (bytes[off] & 0xff);
}
private static int bytesToDword(byte[] bytes, int off) {
return (bytesToWord(bytes, off + 2) << 16) | bytesToWord(bytes, off);
}
}
回答2:
Sam Brightman's solution is for local files only. I added support for Network files:
- Windows shortcut (.lnk) parser in Java?
- http://code.google.com/p/8bits/downloads/detail?name=The_Windows_Shortcut_File_Format.pdf
http://www.javafaq.nu/java-example-code-468.html
public class LnkParser { public LnkParser(File f) throws IOException { parse(f); } private boolean isDirectory; private boolean isLocal; public boolean isDirectory() { return isDirectory; } private String real_file; public String getRealFilename() { return real_file; } private void parse(File f) throws IOException { // read the entire file into a byte buffer FileInputStream fin = new FileInputStream(f); ByteArrayOutputStream bout = new ByteArrayOutputStream(); byte[] buff = new byte[256]; while (true) { int n = fin.read(buff); if (n == -1) { break; } bout.write(buff, 0, n); } fin.close(); byte[] link = bout.toByteArray(); parseLink(link); } private void parseLink(byte[] link) { // get the flags byte byte flags = link[0x14]; // get the file attributes byte final int file_atts_offset = 0x18; byte file_atts = link[file_atts_offset]; byte is_dir_mask = (byte)0x10; if ((file_atts & is_dir_mask) > 0) { isDirectory = true; } else { isDirectory = false; } // if the shell settings are present, skip them final int shell_offset = 0x4c; final byte has_shell_mask = (byte)0x01; int shell_len = 0; if ((flags & has_shell_mask) > 0) { // the plus 2 accounts for the length marker itself shell_len = bytes2short(link, shell_offset) + 2; } // get to the file settings int file_start = 0x4c + shell_len; final int file_location_info_flag_offset_offset = 0x08; int file_location_info_flag = link[file_start + file_location_info_flag_offset_offset]; isLocal = (file_location_info_flag & 2) == 0; // get the local volume and local system values //final int localVolumeTable_offset_offset = 0x0C; final int basename_offset_offset = 0x10; final int networkVolumeTable_offset_offset = 0x14; final int finalname_offset_offset = 0x18; int finalname_offset = link[file_start + finalname_offset_offset] + file_start; String finalname = getNullDelimitedString(link, finalname_offset); if (isLocal) { int basename_offset = link[file_start + basename_offset_offset] + file_start; String basename = getNullDelimitedString(link, basename_offset); real_file = basename + finalname; } else { int networkVolumeTable_offset = link[file_start + networkVolumeTable_offset_offset] + file_start; int shareName_offset_offset = 0x08; int shareName_offset = link[networkVolumeTable_offset + shareName_offset_offset] + networkVolumeTable_offset; String shareName = getNullDelimitedString(link, shareName_offset); real_file = shareName + "\\" + finalname; } } private static String getNullDelimitedString(byte[] bytes, int off) { int len = 0; // count bytes until the null character (0) while (true) { if (bytes[off + len] == 0) { break; } len++; } return new String(bytes, off, len); } /* * convert two bytes into a short note, this is little endian because it's * for an Intel only OS. */ private static int bytes2short(byte[] bytes, int off) { return ((bytes[off + 1] & 0xff) << 8) | (bytes[off] & 0xff); } /** * Returns the value of the instance variable 'isLocal'. * * @return Returns the isLocal. */ public boolean isLocal() { return isLocal; } }
回答3:
I can recommend this repository on GitHub:
https://github.com/BlackOverlord666/mslinks
There I've found a simple solution to create shortcuts:
ShellLink.createLink("path/to/existing/file.txt", "path/to/the/future/shortcut.lnk");
If you want to read shortcuts:
File shortcut = ...;
String pathToExistingFile = new ShellLink(shortcut).resolveTarget();
If you want to change the icon of the shortcut, use:
ShellLink sl = ...;
sl.setIconLocation("/path/to/icon/file");
You can edit most properties of the shortcutlink such as working directory, tooltip text, icon, command line arguments, hotkeys, create links to LAN shared files and directories and much more...
Hope this helps you :)
Kind regards Josua Frank
回答4:
I've also worked( now have no time for that) on '.lnk' in Java. My code is here
It's little messy( some testing trash) but local and network parsing works good. Creating links is implemented too. Please test and send me patches.
Parsing example:
Shortcut scut = Shortcut.loadShortcut(new File("C:\\t.lnk"));
System.out.println(scut.toString());
Creating new link:
Shortcut scut = new Shortcut(new File("C:\\temp"));
OutputStream os = new FileOutputStream("C:\\t.lnk");
os.write(scut.getBytes());
os.flush();
os.close();
回答5:
The code plan9assembler linked to appears to work with minor modification. I think it's just the "& 0xff" to prevent sign extension when bytes are upcast to ints in the bytes2short function that need changing. I've added the functionality described in http://www.i2s-lab.com/Papers/The_Windows_Shortcut_File_Format.pdf to concatenate the "final part of the pathname" even though in practice this doesn't seem to be used in my examples. I've not added any error checking to the header or dealt with network shares. Here's what I'm using now:
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.text.DecimalFormat;
import java.text.NumberFormat;
public class LnkParser {
public LnkParser(File f) throws Exception {
parse(f);
}
private boolean is_dir;
public boolean isDirectory() {
return is_dir;
}
private String real_file;
public String getRealFilename() {
return real_file;
}
private void parse(File f) throws Exception {
// read the entire file into a byte buffer
FileInputStream fin = new FileInputStream(f);
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buff = new byte[256];
while (true) {
int n = fin.read(buff);
if (n == -1) {
break;
}
bout.write(buff, 0, n);
}
fin.close();
byte[] link = bout.toByteArray();
// get the flags byte
byte flags = link[0x14];
// get the file attributes byte
final int file_atts_offset = 0x18;
byte file_atts = link[file_atts_offset];
byte is_dir_mask = (byte) 0x10;
if ((file_atts & is_dir_mask) > 0) {
is_dir = true;
} else {
is_dir = false;
}
// if the shell settings are present, skip them
final int shell_offset = 0x4c;
final byte has_shell_mask = (byte) 0x01;
int shell_len = 0;
if ((flags & has_shell_mask) > 0) {
// the plus 2 accounts for the length marker itself
shell_len = bytes2short(link, shell_offset) + 2;
}
// get to the file settings
int file_start = 0x4c + shell_len;
// get the local volume and local system values
final int basename_offset_offset = 0x10;
final int finalname_offset_offset = 0x18;
int basename_offset = link[file_start + basename_offset_offset]
+ file_start;
int finalname_offset = link[file_start + finalname_offset_offset]
+ file_start;
String basename = getNullDelimitedString(link, basename_offset);
String finalname = getNullDelimitedString(link, finalname_offset);
real_file = basename + finalname;
}
private static String getNullDelimitedString(byte[] bytes, int off) {
int len = 0;
// count bytes until the null character (0)
while (true) {
if (bytes[off + len] == 0) {
break;
}
len++;
}
return new String(bytes, off, len);
}
/*
* convert two bytes into a short note, this is little endian because it's
* for an Intel only OS.
*/
private static int bytes2short(byte[] bytes, int off) {
return ((bytes[off + 1] & 0xff) << 8) | (bytes[off] & 0xff);
}
}
回答6:
This short code is really usefull...
But two fixes are needed:
the isPotentialValidLink improved not to load file if name doesn't end with ".lnk"
public static boolean isPotentialValidLink(final File file) { final int minimum_length = 0x64; boolean isPotentiallyValid = false; if (file.getName().toLowerCase().endsWith(".lnk")) try (final InputStream fis = new FileInputStream(file)) { isPotentiallyValid = file.isFile() && fis.available() >= minimum_length && isMagicPresent(getBytes(fis, 32)); } catch (Exception e) { // forget it } return isPotentiallyValid; }the offset has to be computed with 32bits not only a byte...
final int finalname_offset = bytesToDword(link,file_start + finalname_offset_offset) + file_start; final int basename_offset = bytesToDword(link,file_start + basename_offset_offset) + file_start;
回答7:
The given code works well, but has a bug. A java byte is a signed value from -128 to 127. We want an unsigned value from 0 to 255 to get the correct results. Just change the bytes2short function as follows:
static int bytes2short(byte[] bytes, int off) {
int low = (bytes[off]<0 ? bytes[off]+256 : bytes[off]);
int high = (bytes[off+1]<0 ? bytes[off+1]+256 : bytes[off+1])<<8;
return 0 | low | high;
}
回答8:
The solution of @Code Bling does not work for me for Files in the User directory.
For Example "C:/Users/Username/Filename.txt".
The reason for that is: in The_Windows_Shortcut_File_Format.pdf
that was mentioned by @Stefan Cordes on page 6 it says that only the first 2 bits are important for volumes info. All other bits might be filled with random garbage when the first bit of volumes info is "0".
So if it comes to:
isLocal = (file_location_info_flag & 2) == 0;
then file_location_info_flag might be "3".
This file is still local but this line of code assigns false to isLocal.
So i suggest the following adjustment to @Code Bling's code:
isLocal = (file_location_info_flag & 1) == 1;
来源：https://stackoverflow.com/questions/309495/windows-shortcut-lnk-parser-in-java