extracted method for comparing nullable strings

java/java-impl/src/com/intellij/refactoring/rename/naming/AutomaticUsageRenamer.java

@@ -15,6 +15,7 @@
  */
 package com.intellij.refactoring.rename.naming;
 
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.usages.RenameableUsage;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
@@ -37,15 +38,8 @@ public abstract class AutomaticUsageRenamer<T> {
     myNewName = newName;
     List<T> elements = new ArrayList<T>(renamedElements);
     Collections.sort(elements, new Comparator<T>() {
-      private int compareNullable(@Nullable String s1, @Nullable String s2) {
-        if (s1 != null) {
-          return s2 == null ? 1 : s1.compareTo(s2);
-        }
-        return s2 == null ? 0 : -1;
-      }
-
       public int compare(T o1, T o2) {
-        int i = compareNullable(getSourceName(o1), getSourceName(o2));
+        int i = StringUtil.compare(getSourceName(o1), getSourceName(o2), false);
         if (i != 0) return i;
         return getName(o1).compareTo(getName(o2));
       }

platform/platform-api/src/com/intellij/ui/treeStructure/WeightBasedComparator.java

@@ -16,6 +16,7 @@
 package com.intellij.ui.treeStructure;
 
 import com.intellij.ide.util.treeView.NodeDescriptor;
+import com.intellij.openapi.util.text.StringUtil;
 
 import java.util.Comparator;
 
@@ -57,10 +58,6 @@ public class WeightBasedComparator implements Comparator<NodeDescriptor> {
   }
 
   protected static int compareToString(final NodeDescriptor first, final NodeDescriptor second) {
-    String s1 = first.toString();
-    String s2 = second.toString();
-    if (s1 == null) return s2 == null ? 0 : -1;
-    if (s2 == null) return +1;
-    return s1.compareToIgnoreCase(s2);
+    return StringUtil.compare(first.toString(), second.toString(), true);
   }
 }

platform/platform-impl/src/com/intellij/ide/plugins/PluginManagerColumnInfo.java

@@ -17,6 +17,7 @@ package com.intellij.ide.plugins;
 
 import com.intellij.ide.IdeBundle;
 import com.intellij.openapi.util.IconLoader;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vcs.FileStatus;
 import com.intellij.util.text.DateFormatUtil;
 import com.intellij.util.ui.ColumnInfo;
@@ -94,9 +95,7 @@ class PluginManagerColumnInfo extends ColumnInfo<IdeaPluginDescriptor, String> {
       case COLUMN_NAME:
         return new Comparator<IdeaPluginDescriptor>() {
           public int compare(IdeaPluginDescriptor o1, IdeaPluginDescriptor o2) {
-            String name1 = o1.getName();
-            String name2 = o2.getName();
-            return compareStrings(name1, name2);
+            return StringUtil.compare(o1.getName(), o2.getName(), true);
           }
         };
 
@@ -120,9 +119,7 @@ class PluginManagerColumnInfo extends ColumnInfo<IdeaPluginDescriptor, String> {
       case COLUMN_CATEGORY:
         return new Comparator<IdeaPluginDescriptor>() {
           public int compare(IdeaPluginDescriptor o1, IdeaPluginDescriptor o2) {
-            String cat1 = o1.getCategory();
-            String cat2 = o2.getCategory();
-            return compareStrings(cat1, cat2);
+            return StringUtil.compare(o1.getCategory(), o2.getCategory(), true);
           }
         };
 
@@ -148,21 +145,6 @@ class PluginManagerColumnInfo extends ColumnInfo<IdeaPluginDescriptor, String> {
     }
   }
 
-  public static int compareStrings(String str1, String str2) {
-    if (str1 == null && str2 == null) {
-      return 0;
-    }
-    else if (str1 == null) {
-      return -1;
-    }
-    else if (str2 == null) {
-      return 1;
-    }
-    else {
-      return str1.compareToIgnoreCase(str2);
-    }
-  }
-
   @SuppressWarnings({"HardCodedStringLiteral"})
   public static String getFormattedSize(String size) {
     if (size.equals("-1")) {

platform/util/src/com/intellij/openapi/util/text/StringUtil.java

@@ -1800,6 +1800,13 @@ public class StringUtil {
     return res;
   }
 
+  public static int compare(@Nullable String s1, @Nullable String s2, boolean ignoreCase) {
+    if (s1 == s2) return 0;
+    if (s1 == null) return -1;
+    if (s2 == null) return 1;
+    return ignoreCase ? s1.compareToIgnoreCase(s2) : s1.compareTo(s2);
+  }
+
   public static int hashCode(@NotNull CharSequence s) {
     int result = 0;
     for (int i = 0; i < s.length(); i++) {