flatlaf-natives-windows: reworked linking/loading of jawt.dll; now loading jawt.dll when first used (issue #673)

CHANGELOG.md

@@ -24,6 +24,9 @@ FlatLaf Change Log
     not visible. (issue #686)
   - "Monocai" theme: Fixed unreadable text color of default buttons. (issue
     #693)
+- Native Windows libraries: Fixed crash when running in Java 8 and newer Java
+  version is installed in `PATH` environment variable and using class
+  `SystemInfo` before AWT initialization. (issue #673)
 
 
 ## 3.1.1

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

@@ -61,13 +61,20 @@ class FlatNativeLibrary
 			classifier = SystemInfo.isX86_64 ? "windows-x86_64" : "windows-x86";
 			ext = "dll";
 
-			// In Java 8, load jawt.dll (part of JRE) explicitly because it
+			// Do not load jawt.dll (part of JRE) here explicitly because
-			// is not found when running application with <jdk>/bin/java.exe.
+			// the FlatLaf native library flatlaf.dll may be loaded very early on Windows
-			// When using <jdk>/jre/bin/java.exe, it is found.
+			// (e.g. from class com.formdev.flatlaf.util.SystemInfo) and before AWT is
-			// jawt.dll is located in <jdk>/jre/bin/.
+			// initialized (and awt.dll is loaded). Loading jawt.dll also loads awt.dll.
-			// Java 9 and later do not have this problem,
+			// In Java 8, loading jawt.dll before AWT is initialized may load
-			// but load jawt.dll anyway to be on the safe side.
+			// a wrong version of awt.dll if a newer Java version (e.g. 19)
-			loadJAWT();
+			// is in PATH environment variable. Then Java 19 awt.dll and Java 8 awt.dll
+			// are loaded at same time and calling JAWT_GetAWT() crashes the application.
+			//
+			// To avoid this, flatlaf.dll is not linked to jawt.dll,
+			// which avoids loading jawt.dll when flatlaf.dll is loaded.
+			// Instead flatlaf.dll dynamically loads jawt.dll when first used,
+			// which is guaranteed after AWT initialization.
+
 		} else if( SystemInfo.isLinux && SystemInfo.isX86_64 ) {
 			// Linux: requires x86_64
 

flatlaf-natives/flatlaf-natives-windows/build.gradle.kts

@@ -71,12 +71,11 @@ tasks {
 		val nativesDir = project( ":flatlaf-core" ).projectDir.resolve( "src/main/resources/com/formdev/flatlaf/natives" )
 		val is64Bit = name.contains( "64" )
 		val libraryName = if( is64Bit ) "flatlaf-windows-x86_64.dll" else "flatlaf-windows-x86.dll"
-		val jawt = if( is64Bit ) "lib/jawt-x86_64" else "lib/jawt-x86"
 
 		linkerArgs.addAll( toolChain.map {
 			when( it ) {
-				is Gcc, is Clang -> listOf( "-l${jawt}", "-lUser32", "-lGdi32", "-lshell32", "-lAdvAPI32", "-lKernel32", "-lDwmapi" )
+				is Gcc, is Clang -> listOf( "-lUser32", "-lGdi32", "-lshell32", "-lAdvAPI32", "-lKernel32", "-lDwmapi" )
-				is VisualCpp -> listOf( "${jawt}.lib", "User32.lib", "Gdi32.lib", "shell32.lib", "AdvAPI32.lib", "Kernel32.lib", "Dwmapi.lib", "/NODEFAULTLIB" )
+				is VisualCpp -> listOf( "User32.lib", "Gdi32.lib", "shell32.lib", "AdvAPI32.lib", "Kernel32.lib", "Dwmapi.lib", "/NODEFAULTLIB" )
 				else -> emptyList()
 			}
 		} )

flatlaf-natives/flatlaf-natives-windows/lib/README.md

@@ -1,6 +0,0 @@
-Contains libraries used to compile FlatLaf Windows 10 native libraries (DLLs).
-
-- `jawt-x86.lib` is `<jdk>/lib/jawt.lib` from AdoptOpenJDK jdk8u282-b08 32-bit,
-  which is required to build 32-bit DLL
-- `jawt-x86_64.lib` is `<jdk>/lib/jawt.lib` from AdoptOpenJDK jdk8u282-b08
-  64-bit, which is required to build 64-bit DLL

flatlaf-natives/flatlaf-natives-windows/src/main/cpp/FlatWndProc.cpp

@@ -542,10 +542,82 @@ void FlatWndProc::setMenuItemState( HMENU systemMenu, int item, bool enabled ) {
 	::SetMenuItemInfo( systemMenu, item, FALSE, &mii );
 }
 
+//---- window handle ----------------------------------------------------------
+
+#ifdef _WIN64
+#define GETAWT_METHOD_NAME			"JAWT_GetAWT"
+#else
+#define GETAWT_METHOD_NAME			"_JAWT_GetAWT@8"
+#endif
+
+typedef jboolean (JNICALL *JAWT_GetAWT_Type)( JNIEnv*, JAWT* );
+
+static HMODULE jawtModule = NULL;
+static JAWT_GetAWT_Type pJAWT_GetAWT = NULL;
+
+
 HWND getWindowHandle( JNIEnv* env, jobject window ) {
+
+	// flatlaf.dll is not linked to jawt.dll because flatlaf.dll may be loaded
+	// very early on Windows (e.g. from class com.formdev.flatlaf.util.SystemInfo) and
+	// before AWT is initialized (and awt.dll is loaded). Loading jawt.dll also loads awt.dll.
+	// In Java 8, loading jawt.dll before AWT is initialized may load
+	// a wrong version of awt.dll if a newer Java version (e.g. 19)
+	// is in PATH environment variable. Then Java 19 awt.dll and Java 8 awt.dll
+	// are loaded at same time and calling JAWT_GetAWT() crashes the application.
+	//
+	// To avoid this, flatlaf.dll is not linked to jawt.dll,
+	// which avoids loading jawt.dll when flatlaf.dll is loaded.
+	// Instead flatlaf.dll dynamically loads jawt.dll when first used,
+	// which is guaranteed after AWT initialization.
+	//
+	// Load JAWT library from ${java.home}\bin\jawt.dll and use wide chars for path
+	// for the case that Java path uses special characters. (this is similar to JNA)
+
+	// load JAWT library jawt.dll
+	if( jawtModule == NULL ) {
+		// invoke: javaHome = System.getProperty( "java.home" )
+		jclass cls = env->FindClass( "java/lang/System" );
+		jmethodID mid = (cls != NULL) ? env->GetStaticMethodID( cls, "getProperty", "(Ljava/lang/String;)Ljava/lang/String;" ) : NULL;
+		jstring javaHome = (mid != NULL) ? (jstring) env->CallStaticObjectMethod( cls, mid, env->NewStringUTF( "java.home" ) ) : NULL;
+		if( javaHome != NULL ) {
+			// invoke: jawtPath = javaHome.concat( "\\bin\\jawt.dll" )
+			jmethodID mid2 = env->GetMethodID( env->GetObjectClass( javaHome ), "concat", "(Ljava/lang/String;)Ljava/lang/String;" );
+			jstring jawtPath = (mid2 != NULL) ? (jstring) env->CallObjectMethod( javaHome, mid2, env->NewStringUTF( "\\bin\\jawt.dll" ) ) : NULL;
+			if( jawtPath != NULL ) {
+				// convert Java UTF-8 string to Windows wide chars
+				const char* sjawtPath = env->GetStringUTFChars( jawtPath, NULL );
+				int wstr_len = MultiByteToWideChar( CP_UTF8, 0, sjawtPath, -1, NULL, 0 );
+				if( wstr_len > 0 ) {
+					wchar_t* wstr = new wchar_t[wstr_len];
+					if( MultiByteToWideChar( CP_UTF8, 0, sjawtPath, -1, wstr, wstr_len ) == wstr_len ) {
+						// load jawt.dll from Java home
+						jawtModule = LoadLibraryExW( wstr, NULL, LOAD_WITH_ALTERED_SEARCH_PATH );
+					}
+					delete[] wstr;
+				}
+				env->ReleaseStringUTFChars( jawtPath, sjawtPath );
+			}
+		}
+
+		// fallback
+		if( jawtModule == NULL )
+			jawtModule = LoadLibraryA( "jawt.dll" );
+
+		if( jawtModule == NULL )
+			return 0;
+	}
+
+	// get address of method JAWT_GetAWT()
+	if( pJAWT_GetAWT == NULL ) {
+		pJAWT_GetAWT = (JAWT_GetAWT_Type) GetProcAddress( jawtModule, GETAWT_METHOD_NAME );
+		if( pJAWT_GetAWT == NULL )
+			return 0;
+	}
+
 	JAWT awt;
 	awt.version = JAWT_VERSION_1_4;
-	if( !JAWT_GetAWT( env, &awt ) )
+	if( !pJAWT_GetAWT( env, &awt ) )
 		return 0;
 
 	jawt_DrawingSurface* ds = awt.GetDrawingSurface( env, window );
@@ -558,12 +630,15 @@ HWND getWindowHandle( JNIEnv* env, jobject window ) {
 		return 0;
 	}
 
+	HWND hwnd = 0;
+
 	JAWT_DrawingSurfaceInfo* dsi = ds->GetDrawingSurfaceInfo( ds );
-	JAWT_Win32DrawingSurfaceInfo* wdsi = (JAWT_Win32DrawingSurfaceInfo*) dsi->platformInfo;
+	if( dsi != NULL ) {
+		JAWT_Win32DrawingSurfaceInfo* wdsi = (JAWT_Win32DrawingSurfaceInfo*) dsi->platformInfo;
+		hwnd = wdsi->hwnd;
+		ds->FreeDrawingSurfaceInfo( dsi );
+	}
 
-	HWND hwnd = wdsi->hwnd;
-
-	ds->FreeDrawingSurfaceInfo( dsi );
 	ds->Unlock( ds );
 	awt.FreeDrawingSurface( ds );