I'm maintaining a Java Swing application that requires a connection to an instance of Microsoft SQL Server. For various reasons, I opted to replace the native SQL Server driver being used with jTDS (the aforementioned Microsoft drivers were not working at the time and have apparently failed in the field as well). When I try to run the executable .jar outside of the IDE, I run into issues because I'm missing the appropriate ntlmauth.dll dependency.
Before proceeding, it's important to note that this application is being developed and used in an extremely restrictive (Windows-only) environment:
- I cannot install any software that requires Windows UAC authentication
- My users cannot install or run any software that requires UAC authentication
- This currently means I cannot write files to System32 or JAVA_HOME, and cannot use any sort of ProcessBuilder tomfoolery to start another JVM with whatever command line arguments I need
- I cannot use executable wrappers/installers that would only require the UAC permission for the first time installation/setup
The solution I'm trying is a combination of this one and this one to check it--essentially packaging the .dll inside of the .jar, then extracting it and loading it if necessary--as most of the other solutions I've found have been incompatible with the above restrictions; however, I'm running into an issue where even after the native library is ostensibly "loaded," I get an exception saying it isn't.
My pre-startup code:
private static final String LIB_BIN = "/lib-bin/";
private static final String JTDS_AUTH = "ntlmauth";
// load required JTDS binaries
static {
logger.info("Attempting to load library {}.dll", JTDS_AUTH);
try {
System.loadLibrary(JTDS_AUTH);
} catch (UnsatisfiedLinkError e) {
loadFromJar();
}
try {
// do some quick checks to make sure that went ok
NativeLibraries nl = new NativeLibraries();
logger.debug("Loaded libraries: {}", nl.getLoadedLibraries().toString());
} catch (NoSuchFieldException ex) {
logger.info("Native library checker load failed", ex);
}
}
/**
* When packaged into JAR extracts DLLs, places these into
*/
private static void loadFromJar() {
// we need to put DLL in temp dir
String path = ***;
loadLib(path, JTDS_AUTH);
}
/**
* Puts library to temp dir and loads to memory
*/
private static void loadLib(String path, String name) {
name = name + ".dll";
try {
// have to use a stream
InputStream in = net.sourceforge.jtds.jdbc.JtdsConnection.class.getResourceAsStream(LIB_BIN + name);
// always write to different location
File fileOut = new File(System.getProperty("java.io.tmpdir") + "/" + path + LIB_BIN + name);
logger.info("Writing dll to: " + fileOut.getAbsolutePath());
OutputStream out = FileUtils.openOutputStream(fileOut);
IOUtils.copy(in, out);
in.close();
out.close();
System.load(fileOut.toString());
} catch (Exception e) {
logger.error("Exception with native library loader", e);
JOptionPane.showMessageDialog(null, "Exception loading native libraries: " + e.getLocalizedMessage(), "Exception", JOptionPane.ERROR_MESSAGE);
}
}
As you can see, I basically copied the solution from the first link verbatim, with a few minor modifications just to try and get the application running. I also copied the class from the second link and named it NativeLibraries, the invocation of that method is fairly irrelevant but it shows up in the logs.
Anyway here are the relevant bits of the log output on starting up the application:
2015-07-20 12:32:33 INFO - Attempting to load library ntlmauth.dll
2015-07-20 12:32:33 INFO - Writing dll to: C:\Users\***\lib-bin\ntlmauth.dll
2015-07-20 12:32:33 DEBUG - Loaded libraries: [C:\Program Files\Java\jre1.8.0_45\bin\zip.dll, C:\Program Files\Java\jre1.8.0_45\bin\prism_d3d.dll, C:\Program Files\Java\jre1.8.0_45\bin\prism_sw.dll, C:\Program Files\Java\jre1.8.0_45\bin\msvcr100.dll, C:\Program Files\Java\jre1.8.0_45\bin\glass.dll, C:\Program Files\Java\jre1.8.0_45\bin\net.dll, C:\Users\***\lib-bin\ntlmauth.dll]
2015-07-20 12:32:33 INFO - Application startup
***
2015-07-20 12:32:36 ERROR - Database exception
java.sql.SQLException: I/O Error: SSO Failed: Native SSPI library not loaded. Check the java.library.path system property.
at net.sourceforge.jtds.jdbc.TdsCore.login(TdsCore.java:654) ~[jtds-1.3.1.jar:1.3.1]
at net.sourceforge.jtds.jdbc.JtdsConnection.<init>(JtdsConnection.java:371) ~[jtds-1.3.1.jar:1.3.1]
at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:184) ~[jtds-1.3.1.jar:1.3.1]
at java.sql.DriverManager.getConnection(Unknown Source) ~[na:1.8.0_45]
at java.sql.DriverManager.getConnection(Unknown Source) ~[na:1.8.0_45]
One can see that the library was, indeed, "loaded," from the third line in the log (it's the last entry, if you don't feel like scrolling). However, I simply used the class that I felt like was probably using the native libraries (I also tried the TdsCore class to no avail), as the example that showed how to do this was just using a random class from the package the library was needed in.
Is there something I'm missing here? I'm not very experienced with the JNI or the inner workings of ClassLoaders, so I might just be loading it wrong. Any advice or suggestions would be greatly appreciated!
