Native libraries: system property flatlaf.nativeLibraryPath now supports loading native libraries named the same as on Maven central; improved log messages for loading fails (issue #797)

CHANGELOG.md

@@ -3,6 +3,12 @@ FlatLaf Change Log
 
 ## 3.4-SNAPSHOT
 
+#### New features and improvements
+
+- Native libraries: System property `flatlaf.nativeLibraryPath` now supports
+  loading native libraries named the same as on Maven central. Improved log
+  messages for loading fails.
+
 #### Fixed bugs
 
 - JIDE CommandMenuBar: Fixed `ClassCastException` when JIDE command bar displays

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatSystemProperties.java

@@ -172,19 +172,33 @@ public interface FlatSystemProperties
 	String USE_NATIVE_LIBRARY = "flatlaf.useNativeLibrary";
 
 	/**
-	 * Specifies a directory in which the native FlatLaf libraries have been extracted.
+	 * Specifies a directory in which the FlatLaf native libraries are searched for.
 	 * The path can be absolute or relative to current application working directory.
 	 * This can be used to avoid extraction of the native libraries to the temporary directory at runtime.
 	 * <p>
-	 * If the value is {@code "system"}, then {@link System#loadLibrary(String)} is
+	 * If the value is {@code "system"} (supported since FlatLaf 2.6),
-	 * used to load the native library.
+	 * then {@link System#loadLibrary(String)} is used to load the native library.
-	 * Searches for the native library in classloader of caller
+	 * This searches for the native library in classloader of caller
 	 * (using {@link ClassLoader#findLibrary(String)}) and in paths specified
 	 * in system properties {@code sun.boot.library.path} and {@code java.library.path}.
-	 * (supported since FlatLaf 2.6)
 	 * <p>
 	 * If the native library can not be loaded from the given path (or via {@link System#loadLibrary(String)}),
 	 * then the embedded native library is extracted to the temporary directory and loaded from there.
+	 * <p>
+	 * The file names of the native libraries must be either:
+	 * <ul>
+	 *   <li>the same as in flatlaf.jar in package 'com/formdev/flatlaf/natives' (required for "system") or
+	 *   <li>when downloaded from Maven central then as described here:
+	 *     <a href="https://www.formdev.com/flatlaf/native-libraries/">https://www.formdev.com/flatlaf/native-libraries/</a>
+	 *     (requires FlatLaf 3.4)
+	 * </ul>
+	 * <p>
+	 * <strong>Note</strong>: Since FlatLaf 3.1 it is recommended to download the
+	 * FlatLaf native libraries from Maven central and distribute them with your
+	 * application in the same directory as flatlaf.jar.
+	 * Then it is <strong>not necessary</strong> to set this system property.
+	 * See <a href="https://www.formdev.com/flatlaf/native-libraries/">https://www.formdev.com/flatlaf/native-libraries/</a>
+	 * for details.
 	 *
 	 * @since 2
 	 */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeLibrary.java

@@ -117,13 +117,32 @@ class FlatNativeLibrary
 				if( library.isLoaded() )
 					return library;
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find library " + libraryName + " in java.library.path, using extracted library instead", null );
+				LoggingFacade.INSTANCE.logSevere( "Did not find library '" + System.mapLibraryName( libraryName )
+					+ "' in java.library.path '" + System.getProperty( "java.library.path" )
+					+ "', using extracted library instead", null );
 			} else {
+				// try standard library naming scheme
+				// (same as in flatlaf.jar in package 'com/formdev/flatlaf/natives')
 				File libraryFile = new File( libraryPath, System.mapLibraryName( libraryName ) );
 				if( libraryFile.exists() )
 					return new NativeLibrary( libraryFile, true );
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find external library " + libraryFile + ", using extracted library instead", null );
+				// try Maven naming scheme
+				// (see https://www.formdev.com/flatlaf/native-libraries/)
+				String libraryName2 = null;
+				File jarFile = getJarFile();
+				if( jarFile != null ) {
+					libraryName2 = buildLibraryName( jarFile, classifier, ext );
+					File libraryFile2 = new File( libraryPath, libraryName2 );
+					if( libraryFile2.exists() )
+						return new NativeLibrary( libraryFile2, true );
+				}
+
+				LoggingFacade.INSTANCE.logSevere( "Did not find library '"
+					+ libraryFile.getName()
+					+ (libraryName2 != null ? ("' or '" + libraryName2) : "")
+					+ "' in '" + libraryFile.getParentFile().getAbsolutePath()
+					+ "', using extracted library instead", null );
 			}
 		}
 
@@ -151,6 +170,33 @@ class FlatNativeLibrary
 	 *     flatlaf-3.1-linux-x86_64.so
 	 */
 	private static File findLibraryBesideJar( String classifier, String ext ) {
+		// get location of FlatLaf jar (or fat/uber application jar)
+		File jarFile = getJarFile();
+		if( jarFile == null )
+			return null;
+
+		// build library file
+		String libraryName = buildLibraryName( jarFile, classifier, ext );
+		File parent = jarFile.getParentFile();
+
+		// check whether native library exists in same directory as jar
+		File libraryFile = new File( parent, libraryName );
+		if( libraryFile.isFile() )
+			return libraryFile;
+
+		// if jar is in "lib" directory, then also check whether native library exists
+		// in "../bin" directory
+		if( parent.getName().equalsIgnoreCase( "lib" ) ) {
+			libraryFile = new File( parent.getParentFile(), "bin/" + libraryName );
+			if( libraryFile.isFile() )
+				return libraryFile;
+		}
+
+		// native library not found
+		return null;
+	}
+
+	private static File getJarFile() {
 		try {
 			// get location of FlatLaf jar
 			CodeSource codeSource = FlatNativeLibrary.class.getProtectionDomain().getCodeSource();
@@ -168,31 +214,19 @@ class FlatNativeLibrary
 			if( !jarFile.isFile() )
 				return null;
 
-			// build library file
+			return jarFile;
-			String jarName = jarFile.getName();
-			String jarBasename = jarName.substring( 0, jarName.lastIndexOf( '.' ) );
-			File parent = jarFile.getParentFile();
-			String libraryName = jarBasename
-				+ (jarBasename.contains( "flatlaf" ) ? "" : "-flatlaf")
-				+ '-' + classifier + '.' + ext;
-
-			// check whether native library exists in same directory as jar
-			File libraryFile = new File( parent, libraryName );
-			if( libraryFile.isFile() )
-				return libraryFile;
-
-			// if jar is in "lib" directory, then also check whether library exists
-			// in "../bin" directory
-			if( parent.getName().equalsIgnoreCase( "lib" ) ) {
-				libraryFile = new File( parent.getParentFile(), "bin/" + libraryName );
-				if( libraryFile.isFile() )
-					return libraryFile;
-			}
 		} catch( Exception ex ) {
 			LoggingFacade.INSTANCE.logSevere( ex.getMessage(), ex );
+			return null;
 		}
+	}
 
-		return null;
+	private static String buildLibraryName( File jarFile, String classifier, String ext ) {
+		String jarName = jarFile.getName();
+		String jarBasename = jarName.substring( 0, jarName.lastIndexOf( '.' ) );
+		return jarBasename
+			+ (jarBasename.contains( "flatlaf" ) ? "" : "-flatlaf")
+			+ '-' + classifier + '.' + ext;
 	}
 
 	private static void loadJAWT() {