File handle leak on Win with Java 11(.0.2)

Signed-off-by: Snjezana Peco <[email protected]>

org.eclipse.lsp4xml/src/main/java/org/eclipse/lsp4xml/commons/ParentProcessWatcher.java

@@ -28,6 +28,7 @@
 public final class ParentProcessWatcher implements Runnable, Function<MessageConsumer, MessageConsumer>{
 
 	private static final Logger LOGGER = Logger.getLogger(ParentProcessWatcher.class.getName());
+	private static final boolean isJava1x = System.getProperty("java.version").startsWith("1.");
 
 	/**
 	 * Exit code returned when XML Language Server is forced to exit.
@@ -106,6 +107,28 @@ private boolean parentProcessStillRunning() {
 				// On Windows, when the Java LS is idle, we need to explicitly request a GC, 
 				// to prevent an accumulation of zombie processes, as finalize() will be called.
 				if (isWindows) {
+					// Java >= 9 doesn't close the handle when the process is garbage collected
+					// We need to close the opened streams
+					if (!isJava1x) {
+						try {
+							if (process.getInputStream() != null) {
+								process.getInputStream().close();
+							}
+						} catch (IOException e) {
+						}
+						try {
+							if (process.getOutputStream() != null) {
+								process.getOutputStream().close();
+							}
+						} catch (IOException e) {
+						}
+						try {
+							if (process.getErrorStream() != null) {
+								process.getErrorStream().close();
+							}
+						} catch (IOException e) {
+						}
+					}
 					System.gc();
 				}
 			}