Java tutorial
//package com.java2s; /* * Copyright (C) 2007 The Guava Authors * * 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 android.support.annotation.Nullable; import java.util.List; public class Main { public static <T> List<T> assertNotNullOrNotEmpty(List<T> reference, @Nullable Object errorMessage) { if (reference == null || reference.isEmpty()) { throw new IllegalArgumentException(String.valueOf(errorMessage)); } return reference; } }