use isEmpty() to improve the readability

Author: thurka

visualvm/core/src/org/graalvm/visualvm/core/explorer/ExplorerNode.java

@@ -109,7 +109,7 @@ public void addNodes(Set<ExplorerNode> newChildren) {
                 break;
             case DataSourceDescriptor.EXPAND_ON_EACH_NEW_CHILD:
             case DataSourceDescriptor.EXPAND_ON_EACH_CHILD_CHANGE:
-                if (newChildren.size() > 0) shouldExpand = true;
+                if (!newChildren.isEmpty()) shouldExpand = true;
                 break;
         }
         if (shouldExpand) ExplorerSupport.sharedInstance().expandNode(this);

visualvm/host/src/org/graalvm/visualvm/host/impl/Ping.java

@@ -137,7 +137,7 @@ void add(Target t) {
     //
     void processPendingTargets() throws IOException {
       synchronized (pending) {
-        while (pending.size() > 0) {
+        while (!pending.isEmpty()) {
           Target t = pending.removeFirst();
           try {
 

visualvm/libs.profiler/lib.profiler.ui/src/org/graalvm/visualvm/lib/ui/components/JCheckTree.java

@@ -391,7 +391,7 @@ private boolean isOverCheckBox(int x, int y) {
     }
 
     private void fireCheckTreeChanged(Collection changedNodes) {
-        if (changedNodes.size() > 0) {
+        if (!changedNodes.isEmpty()) {
             for (CheckTreeListener  l : checkTreeListeners) {
                 l.checkTreeChanged(changedNodes);
             }

visualvm/libs.profiler/lib.profiler.ui/src/org/graalvm/visualvm/lib/ui/cpu/StatisticsPanel.java

@@ -659,7 +659,7 @@ private void updateSnippets() {
             container.add((JComponent) snippets.get(i), constraints);
         }
 
-        if (snippets.size() == 0) {
+        if (snippets.isEmpty()) {
             constraints = new GridBagConstraints();
             constraints.gridx = 0;
             constraints.gridy = 2 + itemPresenters.size() + 1;

visualvm/libs.profiler/lib.profiler.ui/src/org/graalvm/visualvm/lib/ui/jdbc/TablesSelector.java

@@ -189,7 +189,7 @@ public void run() {
         }
 
         private void updateSelectionButtons() {
-            selectAll.setEnabled(selected.size() > 0);
+            selectAll.setEnabled(!selected.isEmpty());
             unselectAll.setEnabled(selected.size() < tables.length);
         }
 

visualvm/libs.profiler/lib.profiler/src/org/graalvm/visualvm/lib/jfluid/utils/MiscUtils.java

@@ -290,7 +290,7 @@ public static String getLiveClassPathSubset(String path, String workingDir) {
         List liveComponents = getPathComponents(path, true, workingDir);
         StringBuilder buf = new StringBuilder(liveComponents.size() * 10);
 
-        if (liveComponents.size() > 0) {
+        if (!liveComponents.isEmpty()) {
             buf.append((String) liveComponents.get(0));
 
             for (int i = 1; i < liveComponents.size(); i++) {

visualvm/libs.profiler/lib.profiler/test/qa-functional/src/org/graalvm/visualvm/lib/jfluid/tests/jfluid/cpu/CPUTestCase.java

@@ -367,7 +367,7 @@ protected void startCPUTest(ProfilerEngineSettings settings, String[] measuredMe
 
             setStatus(STATUS_MEASURED);
 
-            if (methods.size() > 0) {
+            if (!methods.isEmpty()) {
                 Collections.sort(methods);
 
                 for (int mets = 0; mets < methods.size(); mets++) {
@@ -475,7 +475,7 @@ protected void startCPUTest(ProfilerEngineSettings settings, String[] measuredMe
                 time = System.currentTimeMillis();
             }
 
-            if (methods.size() == 0) {
+            if (methods.isEmpty()) {
                 assertTrue("Results were not on the server - issue 65185", false);
             }
         } catch (Exception ex) {

visualvm/libs.profiler/lib.profiler/test/unit/src/org/graalvm/visualvm/lib/jfluid/results/cpu/StackTraceSnapshotBuilderTest.java

@@ -743,8 +743,8 @@ public void testReset() {
 
         instance.reset();
         assertTrue(instance.methodInfos.size()-1 == 0);
-        assertTrue(instance.threadIds.size() == 0);
-        assertTrue(instance.threadNames.size() == 0);
+        assertTrue(instance.threadIds.isEmpty());
+        assertTrue(instance.threadNames.isEmpty());
         assertEquals(-1L, instance.currentDumpTimeStamp);
         //assertEquals(-1L, instance.firstDumpTimeStamp);
         assertEquals(0, instance.stackTraceCount);

visualvm/libs.profiler/profiler.oql/test/unit/src/org/graalvm/visualvm/lib/profiler/oql/repository/api/OQLQueryRepositoryTest.java

@@ -70,7 +70,7 @@ public void testListAllCategories() {
         System.out.println("listAllCategories");
 
         List result = instance.listCategories();
-        assertTrue(result.size() > 0);
+        assertTrue(!result.isEmpty());
     }
 
     /**

visualvm/libs.profiler/profiler.snaptracer/src/org/graalvm/visualvm/lib/profiler/snaptracer/impl/timeline/TimelineChart.java

@@ -395,7 +395,7 @@ protected void computeDataBounds() {
         }
 
         dataBounds.y = 0;
-        Row lastRow = rows.size() > 0 ? rows.get(rows.size() - 1) : null;
+        Row lastRow = rows.isEmpty() ? null : rows.get(rows.size() - 1);
         dataBounds.height = lastRow != null ? lastRow.getOffset() + lastRow.getHeight() : 0;
     }