org.jclouds.openstack.swift.functions.ParseObjectInfoListFromJsonResponse.java Source code

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/*
 * 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.openstack.swift.functions;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;
import static org.jclouds.http.Uris.uriBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.util.List;
import java.util.SortedSet;

import javax.inject.Inject;

import org.jclouds.blobstore.domain.PageSet;
import org.jclouds.blobstore.domain.internal.PageSetImpl;
import org.jclouds.http.HttpRequest;
import org.jclouds.http.functions.ParseJson;
import org.jclouds.json.Json;
import org.jclouds.openstack.swift.domain.ObjectInfo;
import org.jclouds.openstack.swift.domain.internal.ObjectInfoImpl;
import org.jclouds.openstack.swift.options.ListContainerOptions;
import org.jclouds.rest.InvocationContext;
import org.jclouds.rest.internal.GeneratedHttpRequest;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.common.collect.Sets;
import com.google.gson.reflect.TypeToken;
import com.google.inject.TypeLiteral;

/**
 * This parses {@link ObjectInfo} from a gson string.
 * 
 * @author Adrian Cole
 */
public class ParseObjectInfoListFromJsonResponse extends ParseJson<PageSet<ObjectInfo>>
        implements InvocationContext<ParseObjectInfoListFromJsonResponse> {

    private List<Object> args;
    private String container;
    private GeneratedHttpRequest request;
    private ListContainerOptions options;

    @Inject
    public ParseObjectInfoListFromJsonResponse(Json json) {
        super(json, new TypeLiteral<PageSet<ObjectInfo>>() {
        });
    }

    public PageSet<ObjectInfo> apply(InputStream stream) {
        checkState(args != null, "request should be initialized at this point");
        Type listType = new TypeToken<SortedSet<ObjectInfoImpl>>() {
        }.getType();

        try {
            SortedSet<ObjectInfoImpl> list = apply(stream, listType);
            SortedSet<ObjectInfo> returnVal = Sets
                    .newTreeSet(Iterables.transform(list, new Function<ObjectInfoImpl, ObjectInfo>() {
                        public ObjectInfo apply(ObjectInfoImpl from) {
                            return from.toBuilder().container(container).uri(uriBuilder(request.getEndpoint())
                                    .clearQuery().appendPath(from.getName()).build()).build();
                        }
                    }));
            boolean truncated = options.getMaxResults() == returnVal.size();
            String marker = truncated ? returnVal.last().getName() : null;
            return new PageSetImpl<ObjectInfo>(returnVal, marker);
        } catch (IOException e) {
            throw new RuntimeException("problem reading response from request: " + request, e);
        }
    }

    @Override
    public ParseObjectInfoListFromJsonResponse setContext(HttpRequest request) {
        checkArgument(request instanceof GeneratedHttpRequest, "note this handler requires a GeneratedHttpRequest");
        this.request = GeneratedHttpRequest.class.cast(request);
        this.args = this.request.getInvocation().getArgs();
        checkArgument(args.get(0) instanceof String, "arg[0] must be a container name");
        this.container = args.get(0).toString();
        checkArgument(args.get(1) instanceof ListContainerOptions[],
                "arg[1] must be an array of ListContainerOptions");
        ListContainerOptions[] optionsList = (ListContainerOptions[]) args.get(1);
        this.options = optionsList.length > 0 ? optionsList[0] : ListContainerOptions.NONE;
        return this;
    }
}