Cleanup implementation of REST views

- specify return type if possible
- remove unnecessary throw declarations
- convert some of the thrown exceptions to RestExceptions
- do not throw Exception but specific exceptions
- sort throw declarations (first RestExceptions, then other
  exceptions)

Having explicit return types and exceptions makes it easier to
programatically invoke the REST views, e.g. if a plugin wants to add a
REST view that wraps a Gerrit core REST view.

Change-Id: I5c59553b6cfad457f7ec037cceb08936247bf8e8
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/project/SetDashboard.java

@@ -19,11 +19,14 @@ import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
 import com.google.gerrit.extensions.restapi.MethodNotAllowedException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.project.SetDashboard.Input;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 
+import java.io.IOException;
+
 class SetDashboard implements RestModifyView<DashboardResource, Input> {
   static class Input {
     @DefaultInput
@@ -41,7 +44,7 @@ class SetDashboard implements RestModifyView<DashboardResource, Input> {
   @Override
   public Object apply(DashboardResource resource, Input input)
       throws AuthException, BadRequestException, ResourceConflictException,
-      Exception {
+      MethodNotAllowedException, ResourceNotFoundException, IOException {
     if (resource.isProjectDefault()) {
       return defaultSetter.get().apply(resource, input);
     }