Here you can find the source of nullSafeCollection(Collection
public static <T> Collection<T> nullSafeCollection(Collection<T> source)
//package com.java2s; /**// www. ja va 2s . com * JBoss, Home of Professional Open Source. * Copyright 2014 Red Hat, Inc., and individual contributors * as indicated by the @author tags. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.Collection; import java.util.Collections; public class Main { public static <T> Collection<T> nullSafeCollection(Collection<T> source) { return source == null ? Collections.emptyList() : source; } }