feat: print hello world with Java down calling C

java-panama/src/main/java/com/baeldung/java/panama/HelloWorld.java

@@ -0,0 +1,42 @@
+package com.baeldung.java.panama;
+
+import java.lang.foreign.*;
+import java.lang.invoke.MethodHandle;
+import java.util.Objects;
+
+import static java.lang.foreign.ValueLayout.ADDRESS;
+import static java.lang.foreign.ValueLayout.JAVA_INT;
+
+
+public class HelloWorld {
+
+    public static void main(String[] args) throws Throwable {
+
+        String symbolName = "printf";
+        String greetings = "Hello World from Project Panama Baeldung Article";
+
+        Linker nativeLinker = Linker.nativeLinker();
+        SymbolLookup stdlibLookup = nativeLinker.defaultLookup();
+        SymbolLookup loaderLookup = SymbolLookup.loaderLookup();
+
+        FunctionDescriptor functionDescriptor = FunctionDescriptor.of(
+                JAVA_INT.withBitAlignment(32),
+                ADDRESS.withBitAlignment(64)
+        );
+
+        MethodHandle methodHandle =
+                loaderLookup.lookup(symbolName)
+                        .or(() -> stdlibLookup.lookup(symbolName))
+                        .map(
+                                symbolAddress -> nativeLinker.downcallHandle(symbolAddress, functionDescriptor)
+                        ).orElse(null);
+
+
+        Objects.requireNonNull(methodHandle);
+
+        try (MemorySession memorySession = MemorySession.openConfined()) {
+            MemorySegment nativeGreetings = memorySession.allocateUtf8String(greetings + "\n");
+            methodHandle.invoke(nativeGreetings);
+        }
+    }
+}