Android Open Source - AndroidHappyChat Cloud Query

• Back to App/cloud  ↑

From Project

Back to project page AndroidHappyChat.

License

The source code is released under:

Apache License

Java Source Code

/*
 * Copyright (c) 2013 Google Inc./*w w w  . ja v a2s. co  m*/
 *
 * 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 com.google.cloud.backend.android;

import android.util.Base64;

import com.google.cloud.backend.android.mobilebackend.model.QueryDto;
import com.google.gson.Gson;

/**
 * A query object to execute it with {@link CloudBackend}. See
 * {@link CloudBackendTest#testList()} for detailed usage.
 *
 */
public class CloudQuery {

  private static final Gson gson = new Gson();

  /**
   * An enum for specifying sort order of the query.
   */
  public enum Order {
    ASC, DESC
  };

  /**
   * An enum to specify scope of query.
   */
  public enum Scope {
    /**
     * PAST: query will be executed only for the entities that have been stored
     * in past, and will not be executed when the entities will be updated in
     * future.
     */
    PAST,

    /**
     * FUTURE: query will be executed only when entities are updated in future,
     * and will not be executed against the current entities.
     */
    FUTURE,

    /**
     * FUTURE_AND_PAST: query will be executed for the current entities and
     * future updates.
     */
    FUTURE_AND_PAST
  }

  private F filter;

  private final QueryDto queryDto;

  /**
   * Creates an instance of {@link CloudQuery}.
   *
   * @param kindName
   *          Name of the kind that this query will execute with.
   */
  public CloudQuery(String kindName) {
    this.queryDto = new QueryDto();
    this.queryDto.setKindName(kindName);
    this.queryDto.setScope(Scope.PAST.name());
  }

  /**
   * Creates an instance of {@link CloudQuery} from the values of the specified
   * CloudQuery. queryDto field will be deep copied, and filter field will be
   * shallow copied.
   *
   * @param cq
   *          {@link CloudQuery} that will be used for instantiation.
   */
  public CloudQuery(CloudQuery cq) {
    this.queryDto = copyQueryDto(cq.queryDto);
    this.filter = cq.filter;
  }

  private QueryDto copyQueryDto(QueryDto cq) {
    QueryDto ncq = new QueryDto();
    ncq.setFilterDto(cq.getFilterDto());
    ncq.setKindName(cq.getKindName());
    ncq.setLimit(cq.getLimit());
    ncq.setQueryId(cq.getQueryId());
    ncq.setRegId(cq.getRegId());
    ncq.setScope(cq.getScope());
    ncq.setSortAscending(cq.getSortAscending());
    ncq.setSortedPropertyName(cq.getSortedPropertyName());
    ncq.setSubscriptionDurationSec(cq.getSubscriptionDurationSec());
    return ncq;
  }

  /**
   * Sets registration id.
   *
   * @param regId
   */
  protected void setRegId(String regId) {
    this.queryDto.setRegId(regId);
  }

  /**
   * Returns a kind name of this query.
   *
   * @return kind name
   */
  public String getKindName() {
    return this.queryDto.getKindName();
  }

  /**
   * Set Sort property name and sort order to this query.
   *
   * @param propertyName
   *          Name of the target name.
   * @param sortOrder
   *          {@link Order} of this sort.
   * @return {@link CloudQuery}
   */
  public CloudQuery setSort(String propertyName, Order sortOrder) {
    this.queryDto.setSortedPropertyName(propertyName);
    this.queryDto.setSortAscending(sortOrder == Order.ASC);
    return this;
  }

  /**
   * Set Limit number on the result set to this query.
   *
   * @param limit
   *          Max number of lines for the query result set.
   * @return {@link CloudQuery}
   */
  public CloudQuery setLimit(int limit) {
    this.queryDto.setLimit(limit);
    return this;
  }

  /**
   * Creates a {@link QueryDto} for this CloudQuery.
   *
   * @return {@link QueryDto} for this CloudQuery
   */
  protected QueryDto convertToQueryDto() {

    // generate FilterDto
    if (filter != null) {
      this.queryDto.setFilterDto(filter.getFilterDto());
    }
    return this.queryDto;
  }

  /**
   * Returns {@link F} (filter) for this query.
   *
   * @return {@link F}
   */
  public F getFilter() {
    return filter;
  }

  /**
   * Sets a filter {@link F} for this query.
   *
   * @param filter
   * @return {@link CloudQuery}
   */
  public CloudQuery setFilter(F filter) {
    this.filter = filter;
    return this;
  }

  /**
   * Sets a {@link Scope} of this query.
   *
   * @param scope
   *          {@link Scope} of this query.
   * @return {@link CloudQuery}
   */
  public CloudQuery setScope(Scope scope) {
    this.queryDto.setScope(scope.name());
    return this;
  }

  /**
   * Returns {@link Scope} of this query.
   *
   * @return
   */
  public Scope getScope() {
    return Scope.valueOf(this.queryDto.getScope());
  }

  /**
   * Returns true if this query is a continuous query.
   *
   * @return
   */
  public boolean isContinuous() {
    return (getScope() == Scope.FUTURE || getScope() == Scope.FUTURE_AND_PAST);
  }

  /**
   * Sets subscription duration (in sec) for this query.
   *
   * @param duration
   */
  public void setSubscriptionDurationSec(int duration) {
    this.queryDto.setSubscriptionDurationSec(duration);
  }

  @Override
  public String toString() {
    return "CloudQuery (" + this.queryDto.getKindName() + "/" + getScope() + "): filter: " + filter;
  }

  /**
   * Sets the specified queryId to this query. This method will be used when
   * developer want to control identity of each query explicitly, such as
   * grouping multiple {@link CloudQuery} as one query and map it to one
   * handler.
   *
   * @param queryId
   *          {@link String} that identifies each query
   */
  public void setQueryId(String queryId) {
    this.queryDto.setQueryId(queryId);
  }

  /**
   * Returns queryId of this query. Unless developer sets it by
   * {@link #setQueryId(String)} explicitly, this method will return an ID based
   * on the query condition. It means the same ID will be returned for multiple
   * {@link CloudQuery}s if they have the same query condition.
   *
   * @return
   */
  public String getQueryId() {
    setDefaultQueryIdIfNeeded();
    return this.queryDto.getQueryId();
  }

  private void setDefaultQueryIdIfNeeded() {
    if (this.queryDto.getQueryId() == null) {
      int queryHash = (gson.toJson(queryDto) + gson.toJson(filter)).hashCode();
      String queryId = Base64.encodeToString(String.valueOf(queryHash).getBytes(),
          Base64.NO_PADDING | Base64.NO_WRAP);
      this.queryDto.setQueryId(queryId);
    }
  }
}

Java Source Code List

• Back to App/cloud  ↑