| 1 | /** |
| 2 | * Licensed to jclouds, Inc. (jclouds) under one or more |
| 3 | * contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. jclouds licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
| 17 | * under the License. |
| 18 | */ |
| 19 | package org.jclouds.functions; |
| 20 | |
| 21 | import static com.google.common.base.Preconditions.checkArgument; |
| 22 | import static com.google.common.base.Preconditions.checkNotNull; |
| 23 | |
| 24 | import java.lang.reflect.Array; |
| 25 | |
| 26 | import javax.inject.Singleton; |
| 27 | |
| 28 | import com.google.common.base.Function; |
| 29 | import com.google.common.base.Joiner; |
| 30 | import com.google.common.collect.ImmutableList; |
| 31 | import com.google.common.collect.Iterables; |
| 32 | import com.google.common.collect.ImmutableList.Builder; |
| 33 | |
| 34 | /** |
| 35 | * |
| 36 | * @author Adrian Cole |
| 37 | * |
| 38 | */ |
| 39 | @Singleton |
| 40 | public class JoinOnComma implements Function<Object, String> { |
| 41 | |
| 42 | public String apply(Object o) { |
| 43 | checkNotNull(o, "input cannot be null"); |
| 44 | if (o.getClass().isArray()) { |
| 45 | Builder<Object> builder = ImmutableList.builder(); |
| 46 | for (int i = 0; i < Array.getLength(o); i++) |
| 47 | builder.add(Array.get(o, i)); |
| 48 | o = builder.build(); |
| 49 | } |
| 50 | checkArgument(o instanceof Iterable<?>, "you must pass an iterable or array"); |
| 51 | Iterable<?> toJoin = (Iterable<?>) o; |
| 52 | checkArgument(Iterables.size(toJoin) > 0, "you must pass an iterable or array with elements"); |
| 53 | return Joiner.on(',').join(toJoin); |
| 54 | } |
| 55 | } |