AbstractUrl: cleanup and notnullification

platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractUrl.java

@@ -17,8 +17,10 @@
 package com.intellij.ide.projectView.impl;
 
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
 import org.jdom.Element;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -29,9 +31,9 @@ public abstract class AbstractUrl {
   protected final String moduleName;
   private final String myType;
 
-  protected AbstractUrl(String url, String moduleName, @NonNls String type) {
+  protected AbstractUrl(String url, @Nullable String moduleName, @NotNull @NonNls String type) {
     myType = type;
-    this.url = url == null ? "" : url;
+    this.url = StringUtil.notNullize(url);
     this.moduleName = moduleName;
   }
 
@@ -47,7 +49,7 @@ public abstract class AbstractUrl {
   @Nullable
   public abstract Object[] createPath(Project project);
 
-  // return null if cannot recognize the element
+  @Nullable("return null if cannot recognize the element")
   public AbstractUrl createUrl(String type, String moduleName, String url){
     if (type.equals(myType)) {
       return createUrl(moduleName, url);
@@ -65,17 +67,13 @@ public abstract class AbstractUrl {
     final AbstractUrl that = (AbstractUrl)o;
 
     if (moduleName != null ? !moduleName.equals(that.moduleName) : that.moduleName != null) return false;
-    if (myType != null ? !myType.equals(that.myType) : that.myType != null) return false;
-    if (url != null ? !url.equals(that.url) : that.url != null) return false;
-
-    return true;
+    return myType.equals(that.myType) && url.equals(that.url);
   }
 
   public int hashCode() {
-    int result;
-    result = (url != null ? url.hashCode() : 0);
+    int result = url.hashCode();
     result = 29 * result + (moduleName != null ? moduleName.hashCode() : 0);
-    result = 29 * result + (myType != null ? myType.hashCode() : 0);
+    result = 29 * result + myType.hashCode();
     return result;
   }
 }

platform/lang-impl/src/com/intellij/ide/projectView/impl/DirectoryUrl.java

@@ -36,7 +36,7 @@ public class DirectoryUrl extends AbstractUrl {
   @NonNls private static final String ELEMENT_TYPE = "directory";
 
   public DirectoryUrl(String url, String moduleName) {
-    super(url, moduleName,ELEMENT_TYPE);
+    super(url, moduleName, ELEMENT_TYPE);
   }
   public static DirectoryUrl create(PsiDirectory directory) {
     Project project = directory.getProject();

platform/lang-impl/src/com/intellij/ide/projectView/impl/ModuleGroupUrl.java

@@ -17,6 +17,7 @@
 package com.intellij.ide.projectView.impl;
 
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
 import org.jetbrains.annotations.NonNls;
 
 
@@ -43,13 +44,7 @@ public class ModuleGroupUrl extends AbstractUrl {
     if (element instanceof ModuleGroup) {
       ModuleGroup group = (ModuleGroup)element;
       final String[] groupPath = group.getGroupPath();
-      StringBuffer sb = new StringBuffer();
-      for (int i = 0; i < groupPath.length; i++) {
-        String s = groupPath[i];
-        sb.append(s);
-        sb.append(";");
-      }
-      return new ModuleGroupUrl(sb.toString());
+      return new ModuleGroupUrl(StringUtil.join(groupPath, ";"));
     }
     return null;
   }

platform/lang-impl/src/com/intellij/ide/projectView/impl/ModuleUrl.java

@@ -28,7 +28,7 @@ public class ModuleUrl extends AbstractUrl {
   @NonNls private static final String ELEMENT_TYPE = "module";
 
   public ModuleUrl(String url, String moduleName) {
-    super(url, moduleName,ELEMENT_TYPE);
+    super(url, moduleName, ELEMENT_TYPE);
   }
 
   @Override