1 /* 2 * Copyright 2012, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 package org.jf.util; 33 34 import com.google.common.collect.ImmutableList; 35 import com.google.common.collect.ImmutableSet; 36 import com.google.common.collect.ImmutableSortedSet; 37 38 import javax.annotation.Nonnull; 39 import javax.annotation.Nullable; 40 41 public class ImmutableUtils { 42 @Nonnull public static <T> ImmutableList<T> nullToEmptyList(@Nullable ImmutableList<T> list) { 43 if (list == null) { 44 return ImmutableList.of(); 45 } 46 return list; 47 } 48 49 @Nonnull public static <T> ImmutableSet<T> nullToEmptySet(@Nullable ImmutableSet<T> set) { 50 if (set == null) { 51 return ImmutableSet.of(); 52 } 53 return set; 54 } 55 56 @Nonnull public static <T> ImmutableSortedSet<T> nullToEmptySortedSet(@Nullable ImmutableSortedSet<T> set) { 57 if (set == null) { 58 return ImmutableSortedSet.of(); 59 } 60 return set; 61 } 62 } 63
