Java tutorial
/* * 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.gogrid.functions; import static com.google.common.base.Preconditions.checkState; import java.util.Map; import javax.inject.Inject; import javax.inject.Singleton; import org.jclouds.domain.Credentials; import org.jclouds.http.HttpResponse; import com.google.common.base.Function; import com.google.common.collect.Iterables; /** * * @author Adrian Cole */ @Singleton public class ParseCredentialsFromJsonResponse implements Function<HttpResponse, Credentials> { private final ParseServerNameToCredentialsMapFromJsonResponse parser; @Inject ParseCredentialsFromJsonResponse(ParseServerNameToCredentialsMapFromJsonResponse parser) { this.parser = parser; } @Override public Credentials apply(HttpResponse input) { Map<String, Credentials> returnVal = parser.apply(input); checkState(!(returnVal.size() > 1), "expecting only 1 credential in response, but had more: " + returnVal.keySet()); return (returnVal.size() > 0) ? Iterables.getOnlyElement(returnVal.values()) : null; } }