com.github.helenusdriver.persistence.Persisted Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of api Show documentation
JPA-like syntax for annotating POJO classes for persistence via Cassandra's Java driver - API
The newest version!
/*
 * Copyright (C) 2015-2015 The Helenus Driver Project Authors.
 *
 * 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.github.helenusdriver.persistence;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * The Persisted annotation can be used on a {@link Column}
 * annotated field to indicate it should be encoded before being persisted to
 * the database using a specified persister. The data type for the column will
 * automatically be set using the data type specified as part of the annotation.
 * When persisting a collection column, each elements of the collection will be
 * be passed into the persister before being saved to the database. The resulting
 * database data type for the column will be changed based on the data type
 * specified here. For example, if the data type is set to "blob" the data type
 * for collection columns would be "list<blob>", "map<?,blob>", or "set<blob>".
 *
 * @copyright 2015-2015 The Helenus Driver Project Authors
 *
 * @author  The Helenus Driver Project Authors
 * @version 1 - Jan 15, 2015 - paouelle - Creation
 *
 * @since 1.0
 */
@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Persisted {
  /**
   * The persister class to use for the column or the elements of the
   * collection column.
   *
   * @author paouelle
   *
   * @return the persister class
   */
  Class> using();

  /**
   * The resulting CQL data type after persistence. For collections, this would
   * be the element's or value's data type. For maps, the data type for the keys
   * is preserved from the column's definition.
   * 
   * Note: that the data type specified cannot be one of
   * {@link DataType#INFERRED}, {@link DataType#LIST}, {@link DataType#SET},
   * or {@link DataType#MAP}. Otherwise an error will be thrown when analyzing
   * the POJO at runtime.
   *
   * @author paouelle
   *
   * @return the resulting CQL data type after persistence
   */
  DataType as();

  /**
   * Persister specific arguments.
   *
   * @author paouelle
   *
   * @return the persister specific arguments
   */
  String[] arguments() default {};
}