8274806: Simplify equals() call on nullable variable and a constant in java.desktop

Reviewed-by: serb, pbansal

src/java.desktop/macosx/classes/sun/lwawt/macosx/CMenuItem.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,7 +55,7 @@ public class CMenuItem extends CMenuComponent implements MenuItemPeer {
 
     private boolean isSeparator() {
         String label = ((MenuItem)getTarget()).getLabel();
-        return (label != null && label.equals("-"));
+        return "-".equals(label);
     }
 
     @Override

src/java.desktop/share/classes/java/awt/Window.java

@@ -417,11 +417,11 @@ public class Window extends Container implements Accessible {
         @SuppressWarnings("removal")
         String s = java.security.AccessController.doPrivileged(
             new GetPropertyAction("java.awt.syncLWRequests"));
-        systemSyncLWRequests = (s != null && s.equals("true"));
+        systemSyncLWRequests = "true".equals(s);
         @SuppressWarnings("removal")
         String s2 = java.security.AccessController.doPrivileged(
             new GetPropertyAction("java.awt.Window.locationByPlatform"));
-        locationByPlatformProp = (s2 != null && s2.equals("true"));
+        locationByPlatformProp = "true".equals(s2);
     }
 
     /**

src/java.desktop/share/classes/javax/swing/DefaultDesktopManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -328,9 +328,9 @@ public class DefaultDesktopManager implements DesktopManager, java.io.Serializab
             Window window = SwingUtilities.getWindowAncestor(f);
             if (window != null && !window.isOpaque()) {
                 dragMode = DEFAULT_DRAG_MODE;
-            } else if (mode != null && mode.equals("outline")) {
+            } else if ("outline".equals(mode)) {
                 dragMode = OUTLINE_DRAG_MODE;
-            } else if (mode != null && mode.equals("faster")
+            } else if ("faster".equals(mode)
                     && f instanceof JInternalFrame
                     && ((JInternalFrame)f).isOpaque() &&
                        (parent == null || parent.isOpaque())) {

src/java.desktop/share/classes/javax/swing/JLayeredPane.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -205,7 +205,7 @@ public class JLayeredPane extends JComponent implements Accessible {
                         (layer = (Integer)((JComponent)c).
                                      getClientProperty(LAYER_PROPERTY)) != null))
                 {
-                    if(layer != null && layer.equals(FRAME_CONTENT_LAYER))
+                    if (FRAME_CONTENT_LAYER.equals(layer))
                         continue;
                     layeredComponentFound = true;
                     break;

src/java.desktop/share/classes/javax/swing/filechooser/FileSystemView.java

@@ -824,7 +824,7 @@ class UnixFileSystemView extends FileSystemView {
     public boolean isComputerNode(File dir) {
         if (dir != null) {
             String parent = dir.getParent();
-            if (parent != null && parent.equals("/net")) {
+            if ("/net".equals(parent)) {
                 return true;
             }
         }

src/java.desktop/share/classes/javax/swing/text/html/HTMLEditorKit.java

@@ -1326,7 +1326,7 @@ public class HTMLEditorKit extends StyledEditorKit implements Accessible {
                 } else if (kind == HTML.Tag.IMPLIED) {
                     String ws = (String) elem.getAttributes().getAttribute(
                         CSS.Attribute.WHITE_SPACE);
-                    if ((ws != null) && ws.equals("pre")) {
+                    if ("pre".equals(ws)) {
                         return new LineView(elem);
                     }
                     return new javax.swing.text.html.ParagraphView(elem);

src/java.desktop/share/classes/sun/java2d/SurfaceDataProxy.java

@@ -37,7 +37,6 @@ import sun.java2d.loops.SurfaceType;
 import sun.java2d.loops.Blit;
 import sun.java2d.loops.BlitBg;
 import sun.awt.image.SurfaceManager;
-import sun.awt.image.SurfaceManager.FlushableCacheData;
 
 import java.security.AccessController;
 import sun.security.action.GetPropertyAction;
@@ -74,7 +73,7 @@ public abstract class SurfaceDataProxy
         @SuppressWarnings("removal")
         String manimg = AccessController.doPrivileged(
             new GetPropertyAction("sun.java2d.managedimages"));
-        if (manimg != null && manimg.equals("false")) {
+        if ("false".equals(manimg)) {
             cachingAllowed = false;
             System.out.println("Disabling managed images");
         }

src/java.desktop/share/classes/sun/print/RasterPrinterJob.java

@@ -1547,7 +1547,7 @@ public abstract class RasterPrinterJob extends PrinterJob {
          * PrintRequestAttributeSet while calling print(attributes)
          */
         JobSheets js = (JobSheets)psvc.getDefaultAttributeValue(JobSheets.class);
-        if (js != null && js.equals(JobSheets.NONE)) {
+        if (JobSheets.NONE.equals(js)) {
             noJobSheet = true;
         }
 

src/java.desktop/unix/classes/sun/awt/X11/XTaskbarPeer.java

@@ -48,7 +48,7 @@ final class XTaskbarPeer implements TaskbarPeer {
         String de = AccessController.doPrivileged(
                         (PrivilegedAction<String>) ()
                                 -> System.getenv("XDG_CURRENT_DESKTOP"));
-        isUnity = de != null && de.equals("Unity");
+        isUnity = "Unity".equals(de);
     }
 
     private static void initWithLock() {

src/java.desktop/unix/classes/sun/print/UnixPrintJob.java

@@ -128,7 +128,7 @@ public class UnixPrintJob implements CancelablePrintJob {
         mDestType = UnixPrintJob.DESTPRINTER;
         JobSheets js = (JobSheets)(service.
                                       getDefaultAttributeValue(JobSheets.class));
-        if (js != null && js.equals(JobSheets.NONE)) {
+        if (JobSheets.NONE.equals(js)) {
             mNoJobSheet = true;
         }
     }

src/java.desktop/windows/classes/sun/awt/windows/WDesktopProperties.java

@@ -268,7 +268,7 @@ final class WDesktopProperties {
 
         Boolean smoothingOn = (Boolean)map.get("win.text.fontSmoothingOn");
 
-        if (smoothingOn != null && smoothingOn.equals(Boolean.TRUE)) {
+        if (Boolean.TRUE.equals(smoothingOn)) {
             Integer typeID = (Integer)map.get("win.text.fontSmoothingType");
             /* "1" is GASP/Standard but we'll also use that if the return
              * value is anything other than "2" for LCD.