org.jclouds.blobstore.options.GetOptions Maven / Gradle / Ivy

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/**
 *
 * Copyright (C) 2010 Cloud Conscious, LLC. 
 *
 * ====================================================================
 * 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.blobstore.options;

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

import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * Contains options supported for HTTP GET operations. 
 * Usage The recommended way to instantiate a GetObjectOptions object is to statically import
 * GetObjectOptions.Builder.* and invoke a static creation method followed by an instance mutator
 * (if needed):
 * 
 * 
 * import static org.jclouds.http.options.GetOptions.Builder.*
 * 
 * 
 * // this will get the first megabyte of an object, provided it wasn't modified since yesterday
 * Future object = client.get("objectName",range(0,1024).ifUnmodifiedSince(new Date().minusDays(1)));
 * 
 * 
 * @author Adrian Cole
 * 
 */
public class GetOptions {

   public static final GetOptions NONE = new GetOptions();

   private final List ranges = new ArrayList();
   private Date ifModifiedSince;
   private Date ifUnmodifiedSince;
   private String ifMatch;
   private String ifNoneMatch;

   /**
    * download the specified range of the object.
    */
   public GetOptions range(long start, long end) {
      checkArgument(start >= 0, "start must be >= 0");
      checkArgument(end >= 0, "end must be >= 0");
      getRanges().add(String.format("%d-%d", start, end));
      return this;
   }

   /**
    * download the specified range of the object.
    */
   public GetOptions startAt(long start) {
      checkArgument(start >= 0, "start must be >= 0");
      getRanges().add(String.format("%d-", start));
      return this;
   }

   /**
    * Only return the object if it has changed since this time.
    * 

    * Not compatible with {@link #ifETagMatches(String)} or {@link #ifUnmodifiedSince(Date)}
    */
   public GetOptions ifModifiedSince(Date ifModifiedSince) {
      checkArgument(getIfMatch() == null,
               "ifETagMatches() is not compatible with ifModifiedSince()");
      checkArgument(getIfUnmodifiedSince() == null,
               "ifUnmodifiedSince() is not compatible with ifModifiedSince()");
      this.ifModifiedSince = checkNotNull(ifModifiedSince, "ifModifiedSince");
      return this;
   }

   /**
    * For use in the header If-Modified-Since
    * 

    * Return the object only if it has been modified since the specified time, otherwise return a
    * 304 (not modified).
    * 
    * @see GetOptions#ifModifiedSince(Date)
    */
   public Date getIfModifiedSince() {
      return this.ifModifiedSince;
   }

   /**
    * Only return the object if it hasn't changed since this time.
    * 

    * Not compatible with {@link #ifETagDoesntMatch(String)} or {@link #ifModifiedSince(Date)}
    */
   public GetOptions ifUnmodifiedSince(Date ifUnmodifiedSince) {
      checkArgument(getIfNoneMatch() == null,
               "ifETagDoesntMatch() is not compatible with ifUnmodifiedSince()");
      checkArgument(getIfModifiedSince() == null,
               "ifModifiedSince() is not compatible with ifUnmodifiedSince()");
      this.ifUnmodifiedSince = checkNotNull(ifUnmodifiedSince, "ifUnmodifiedSince");
      return this;
   }

   /**
    * For use in the header If-Unmodified-Since
    * 

    * Return the object only if it has not been modified since the specified time, otherwise return
    * a 412 (precondition failed).
    * 
    * @see GetOptions#ifUnmodifiedSince(Date)
    */
   public Date getIfUnmodifiedSince() {
      return this.ifUnmodifiedSince;
   }

   /**
    * The object's eTag hash should match the parameter eTag.
    * 
    * 

    * Not compatible with {@link #ifETagDoesntMatch(String)} or {@link #ifModifiedSince(Date)}
    * 
    * @param eTag
    *           hash representing the payload
    */
   public GetOptions ifETagMatches(String eTag) {
      checkArgument(getIfNoneMatch() == null,
               "ifETagDoesntMatch() is not compatible with ifETagMatches()");
      checkArgument(getIfModifiedSince() == null,
               "ifModifiedSince() is not compatible with ifETagMatches()");
      this.ifMatch = checkNotNull(eTag, "eTag");
      return this;
   }

   /**
    * For use in the request header: If-Match
    * 

    * Return the object only if its payload tag (ETag) is the same as the eTag specified, otherwise
    * return a 412 (precondition failed).
    * 
    * @see GetOptions#ifETagMatches(String)
    */
   public String getIfMatch() {
      return this.ifMatch;
   }

   /**
    * The object should not have a eTag hash corresponding with the parameter eTag.
    * 

    * Not compatible with {@link #ifETagMatches(String)} or {@link #ifUnmodifiedSince(Date)}
    * 
    * @param eTag
    *           hash representing the payload
    */
   public GetOptions ifETagDoesntMatch(String eTag) {
      checkArgument(getIfMatch() == null,
               "ifETagMatches() is not compatible with ifETagDoesntMatch()");
      checkArgument(getIfUnmodifiedSince() == null,
               "ifUnmodifiedSince() is not compatible with ifETagDoesntMatch()");
      this.ifNoneMatch = checkNotNull(eTag, "eTag");
      return this;
   }

   /**
    * For use in the request header: If-None-Match
    * 

    * Return the object only if its payload tag (ETag) is different from the one specified,
    * otherwise return a 304 (not modified).
    * 
    * @see GetOptions#ifETagDoesntMatch(String)
    */
   public String getIfNoneMatch() {
      return this.ifNoneMatch;
   }

   public List getRanges() {
      return ranges;
   }

   public static class Builder {

      /**
       * @see GetOptions#range(long, long)
       */
      public static GetOptions range(long start, long end) {
         GetOptions options = new GetOptions();
         return options.range(start, end);
      }

      /**
       * @see GetOptions#getIfModifiedSince()
       */
      public static GetOptions ifModifiedSince(Date ifModifiedSince) {
         GetOptions options = new GetOptions();
         return options.ifModifiedSince(ifModifiedSince);
      }

      /**
       * @see GetOptions#ifUnmodifiedSince(Date)
       */
      public static GetOptions ifUnmodifiedSince(Date ifUnmodifiedSince) {
         GetOptions options = new GetOptions();
         return options.ifUnmodifiedSince(ifUnmodifiedSince);
      }

      /**
       * @see GetOptions#ifETagMatches(String)
       */
      public static GetOptions ifETagMatches(String eTag) throws UnsupportedEncodingException {
         GetOptions options = new GetOptions();
         return options.ifETagMatches(eTag);
      }

      /**
       * @see GetOptions#ifETagDoesntMatch(String)
       */
      public static GetOptions ifETagDoesntMatch(String eTag) throws UnsupportedEncodingException {
         GetOptions options = new GetOptions();
         return options.ifETagDoesntMatch(eTag);
      }

   }
}