produce less trash objects

java/debugger/openapi/src/com/intellij/debugger/NoDataException.java

@@ -15,7 +15,16 @@
  */
 package com.intellij.debugger;
 
-public class NoDataException extends Exception{
+public class NoDataException extends Exception {
+  public static final NoDataException INSTANCE = new NoDataException();
+
+  /**
+   * @deprecated Use shared {@link com.intellij.debugger.NoDataException#INSTANCE} instead
+   */
+  @Deprecated
+  public NoDataException() {
+  }
+
   @Override
   public Throwable fillInStackTrace() {
     return this;

java/debugger/openapi/src/com/intellij/debugger/engine/JSR45PositionManager.java

@@ -97,7 +97,7 @@ public abstract class JSR45PositionManager<Scope> implements PositionManager {
       LOG.info(e);
     }
     if(sourcePosition == null) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
     return sourcePosition;
   }
@@ -135,7 +135,7 @@ public abstract class JSR45PositionManager<Scope> implements PositionManager {
   private void checkSourcePositionFileType(final SourcePosition classPosition) throws NoDataException {
     final FileType fileType = classPosition.getFile().getFileType();
     if(!myFileTypes.contains(fileType)) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
   }
 

plugins/groovy/src/org/jetbrains/plugins/groovy/debugger/GroovyPositionManager.java

@@ -77,11 +77,11 @@ public class GroovyPositionManager implements PositionManager {
       List<Location> locations = getDebugProcess().getVirtualMachineProxy().versionHigher("1.4")
                                  ? type.locationsOfLine(DebugProcess.JAVA_STRATUM, null, line)
                                  : type.locationsOfLine(line);
-      if (locations == null || locations.isEmpty()) throw new NoDataException();
+      if (locations == null || locations.isEmpty()) throw NoDataException.INSTANCE;
       return locations;
     }
     catch (AbsentInformationException e) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
   }
 
@@ -112,7 +112,7 @@ public class GroovyPositionManager implements PositionManager {
 
   private static void checkGroovyFile(@NotNull SourcePosition position) throws NoDataException {
     if (!(position.getFile() instanceof GroovyFileBase)) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
   }
 
@@ -127,7 +127,7 @@ public class GroovyPositionManager implements PositionManager {
 
     qName = findEnclosingName(position);
 
-    if (qName == null) throw new NoDataException();
+    if (qName == null) throw NoDataException.INSTANCE;
     ClassPrepareRequestor waitRequestor = new ClassPrepareRequestor() {
       @Override
       public void processClassPrepare(DebugProcess debuggerProcess, ReferenceType referenceType) {
@@ -205,13 +205,13 @@ public class GroovyPositionManager implements PositionManager {
 
   @Override
   public SourcePosition getSourcePosition(final Location location) throws NoDataException {
-    if (location == null) throw new NoDataException();
+    if (location == null) throw NoDataException.INSTANCE;
 
     PsiFile psiFile = getPsiFileByLocation(getDebugProcess().getProject(), location);
-    if (psiFile == null) throw new NoDataException();
+    if (psiFile == null) throw NoDataException.INSTANCE;
 
     int lineNumber = calcLineIndex(location);
-    if (lineNumber < 0) throw new NoDataException();
+    if (lineNumber < 0) throw NoDataException.INSTANCE;
     return SourcePosition.createFromLine(psiFile, lineNumber);
   }
 
@@ -323,7 +323,7 @@ public class GroovyPositionManager implements PositionManager {
       }
     });
 
-    if (result == null) throw new NoDataException();
+    if (result == null) throw NoDataException.INSTANCE;
     return result;
   }
 

plugins/groovy/src/org/jetbrains/plugins/groovy/springloaded/SpringLoadedPositionManager.java

@@ -62,7 +62,7 @@ public class SpringLoadedPositionManager implements PositionManager {
 
   @Override
   public SourcePosition getSourcePosition(@Nullable Location location) throws NoDataException {
-    throw new NoDataException();
+    throw NoDataException.INSTANCE;
   }
 
   @NotNull
@@ -74,7 +74,7 @@ public class SpringLoadedPositionManager implements PositionManager {
     AccessToken accessToken = ReadAction.start();
     try {
       className = findEnclosingName(classPosition);
-      if (className == null) throw new NoDataException();
+      if (className == null) throw NoDataException.INSTANCE;
 
       line = classPosition.getLine();
     }
@@ -83,7 +83,7 @@ public class SpringLoadedPositionManager implements PositionManager {
     }
 
     List<ReferenceType> referenceTypes = myDebugProcess.getVirtualMachineProxy().classesByName(className);
-    if (referenceTypes.isEmpty()) throw new NoDataException();
+    if (referenceTypes.isEmpty()) throw NoDataException.INSTANCE;
 
     Set<ReferenceType> res = new HashSet<ReferenceType>();
 
@@ -92,7 +92,7 @@ public class SpringLoadedPositionManager implements PositionManager {
     }
 
     if (res.isEmpty()) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
 
     return new ArrayList<ReferenceType>(res);
@@ -101,7 +101,7 @@ public class SpringLoadedPositionManager implements PositionManager {
   @NotNull
   @Override
   public List<Location> locationsOfLine(@NotNull ReferenceType type, @NotNull SourcePosition position) throws NoDataException {
-    throw new NoDataException();
+    throw NoDataException.INSTANCE;
   }
 
   @Nullable
@@ -164,7 +164,7 @@ public class SpringLoadedPositionManager implements PositionManager {
   public ClassPrepareRequest createPrepareRequest(@NotNull ClassPrepareRequestor requestor, @NotNull SourcePosition position) throws NoDataException {
     String className = getOuterClassName(position);
     if (className == null) {
-      throw new NoDataException();
+      throw NoDataException.INSTANCE;
     }
 
     return myDebugProcess.getRequestsManager().createClassPrepareRequest(requestor, className + "*");