jsfaddon Repository NullPointerException

I test the scripts(bikeshop in sample dir of roo) bellow,it works well, but when edit SupplierBean(managed bean of the sample)
like this:
package com.springsource.bikeshop.web;
import com.springsource.bikeshop.domain.Supplier;
import org.springframework.roo.addon.jsf.managedbean.RooJsfManagedBean;
@RooJsfManagedBean(entity = Supplier.class, beanName = "supplierBean")
public class SupplierBean {
public String getHello()

{ return supplierRepository.getClass().toString(); }

}
supplierRepository occured NullPointer Exception. It means supplierRepository is null
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project --topLevelPackage com.springsource.bikeshop
jpa setup --provider ECLIPSELINK --database H2_IN_MEMORY

enum type --class ~.reference.ProductType
enum constant --name Frame
enum constant --name Brakes
enum constant --name Crank
enum constant --name Wheel
enum constant --name Headset
enum constant --name Handlebar
enum constant --name Saddle
enum constant --name Pedal
enum constant --name Cassette
enum constant --name Tyre
enum constant --name Seatpost
enum constant --name Stem
enum constant --name Derailleur
enum constant --name Fork

entity jpa --class ~.domain.Product --activeRecord false --equals --testAutomatically
field string --fieldName name --sizeMax 25 --notNull
field string --fieldName description --sizeMax 250
field enum --fieldName productType --type ~.reference.ProductType --notNull
field date --fieldName releaseDate --type java.util.Date
field number --fieldName weight --type java.math.BigDecimal --decimalMin 0.0 --decimalMax 9.99
field file --fieldName image --contentType JPG
repository jpa --interface ~.domain.ProductRepository

entity jpa --class ~.domain.Supplier --activeRecord false --equals --testAutomatically
field string --fieldName name --sizeMax 25 --notNull
field string --fieldName address --sizeMax 100 --notNull
field string --fieldName description
field number --type int --fieldName supplierNumber --min 1 --max 99
field date --fieldName inceptionDate --type java.util.Date --past
field string --fieldName email --regexp "[a-zA-Z0-9]@[a-zA-Z0-9]\.[a-zA-Z0-9]+"
field set --fieldName products --type ~.domain.Product --mappedBy supplier --notNull false --cardinality ONE_TO_MANY --fetch EAGER
repository jpa --interface ~.domain.SupplierRepository

field reference --fieldName supplier --class ~.domain.Product --type ~.domain.Supplier --notNull

web jsf setup
web jsf all --package ~.web

logging setup --level INFO
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