| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| package org.jclouds.functions; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.lang.reflect.Array; |
| |
| import javax.inject.Singleton; |
| |
| import com.google.common.base.Function; |
| import com.google.common.base.Joiner; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableList.Builder; |
| import com.google.common.collect.Iterables; |
| |
| @Singleton |
| public class JoinOnComma implements Function<Object, String> { |
| |
| public String apply(Object o) { |
| checkNotNull(o, "input cannot be null"); |
| if (o.getClass().isArray()) { |
| Builder<Object> builder = ImmutableList.builder(); |
| for (int i = 0; i < Array.getLength(o); i++) |
| builder.add(Array.get(o, i)); |
| o = builder.build(); |
| } |
| checkArgument(o instanceof Iterable<?>, "you must pass an iterable or array"); |
| Iterable<?> toJoin = (Iterable<?>) o; |
| checkArgument(!Iterables.isEmpty(toJoin), "you must pass an iterable or array with elements"); |
| return Joiner.on(',').join(toJoin); |
| } |
| } |