Added Lck-File that is correctly deleted on JVM-Exit.

src/main/java/org/sqlite/SQLiteJDBCLoader.java

@@ -62,9 +62,46 @@ public class SQLiteJDBCLoader {
      * @return True if SQLite native library is successfully loaded; false otherwise.
      */
     public static boolean initialize() throws Exception {
-        loadSQLiteNativeLibrary();
-        return extracted;
+        // only cleanup before first extract
+		if(!extracted) {
+			cleanup();
+		}
+		loadSQLiteNativeLibrary();
+		return extracted;
     }
+
+
+	/**
+	* Deleted old nativ libraries e.g. on Windows this are not removed on VM-Exit (bug #80)
+	*/
+	static void cleanup(){
+
+		final String ver = org.sqlite.SQLiteJDBCLoader.getVersion();
+		String tempFolder = new	java.io.File(System.getProperty("java.io.tmpdir")).getAbsolutePath();					
+		java.io.File dir = new java.io.File(tempFolder);
+		java.io.File [] files = dir.listFiles(new java.io.FilenameFilter() {
+			@Override
+			public boolean accept(java.io.File dir, String name) {
+				return name.startsWith("sqlite-" + ver);
+			}
+		});
+
+		for (java.io.File tempFile : files) {
+			if(tempFile.getName().indexOf(".lck") > 0) { continue; }
+			java.io.File lckFile = new java.io.File(tempFile.getName() + ".lck");
+			if(!lckFile.exists()) {
+				try{
+					tempFile.delete();
+				}
+				catch(SecurityException ex){
+
+				}
+
+			}
+		}
+
+
+	}
 
     /**
      * @return True if the SQLite JDBC driver is set to pure Java mode; false otherwise.
@@ -181,37 +218,7 @@ private static boolean extractAndLoadLibraryFile(String libFolderForCurrentOS, S
                 extractedLibFile.deleteOnExit();
 				extractedLckFile.deleteOnExit();
 
-				// Add a Shutdown-Hook to remove other unused binaries (dll in temp without lck-file)
-				Runtime.getRuntime().addShutdownHook(new Thread()
-					{
-						@Override
-						public void run()
-						{
-						System.gc();
-						final String ver = org.sqlite.SQLiteJDBCLoader.getVersion();
-
-						String tempFolder = new  	java.io.File(System.getProperty("java.io.tmpdir")).getAbsolutePath();					
-							java.io.File dir = new java.io.File(tempFolder);
-							java.io.File [] files = dir.listFiles(new java.io.FilenameFilter() {
-
-								@Override
-								public boolean accept(java.io.File dir, String name) 
-								{
-									return name.startsWith("sqlite-" + ver);
-								}
-							});
-
-							for (java.io.File tempFile : files) 
-							{
-								if(tempFile.getName().indexOf(".lck") > 0) { continue; }
-								java.io.File lckFile = new java.io.File(tempFile.getName() + ".lck");
-								if(!lckFile.exists()){
-									tempFile.deleteOnExit();
-								}
-							}
-
-						}
-					}); 
+
                 if(writer != null) {
                     writer.close();
                 }