org.jclouds.rackspace.cloudfiles.functions.ParseObjectInfoListFromJsonResponse.java Source code

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Here is the source code for org.jclouds.rackspace.cloudfiles.functions.ParseObjectInfoListFromJsonResponse.java

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/**
 *
 * Copyright (C) 2010 Cloud Conscious, LLC. <info@cloudconscious.com>
 *
 * ====================================================================
 * Licensed 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.rackspace.cloudfiles.functions;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
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.rackspace.cloudfiles.domain.ObjectInfo;
import org.jclouds.rackspace.cloudfiles.domain.internal.ObjectInfoImpl;
import org.jclouds.rackspace.cloudfiles.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 {

    private GeneratedHttpRequest<?> request;

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

    public PageSet<ObjectInfo> apply(InputStream stream) {
        checkState(request != null, "request should be initialized at this point");
        checkState(request.getArgs() != null, "request.getArgs() should be initialized at this point");
        checkArgument(request.getArgs()[0] instanceof String, "arg[0] must be a container name");
        checkArgument(request.getArgs()[1] instanceof ListContainerOptions[],
                "arg[1] must be an array of ListContainerOptions");
        ListContainerOptions[] optionsList = (ListContainerOptions[]) request.getArgs()[1];
        ListContainerOptions options = optionsList.length > 0 ? optionsList[0] : ListContainerOptions.NONE;
        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;
                        }
                    }));
            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<?>) request;
        return this;
    }
}