content: /*
   * 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 com.datastax.oss.driver.api.mapper.annotations;
  
  import com.datastax.oss.driver.api.core.MappedAsyncPagingIterable;
  import com.datastax.oss.driver.api.core.PagingIterable;
  import com.datastax.oss.driver.api.core.cql.AsyncResultSet;
  import com.datastax.oss.driver.api.core.cql.ResultSet;
  import com.datastax.oss.driver.api.core.cql.Row;
  import com.datastax.oss.driver.api.core.data.GettableByName;
  import com.datastax.oss.driver.api.core.data.UdtValue;
  import java.lang.annotation.ElementType;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  
  /**
   * Annotates a {@link Dao} method that converts a core driver data structure into one or more
   * instances of an {@link Entity} class.
   *
   * <p>Example:
   *
   * <pre>
   * &#64;Dao
   * public interface ProductDao {
   *   &#64;GetEntity
   *   Product asProduct(Row row);
   * }
   * </pre>
   *
   * The generated code will retrieve each entity property from the source, such as:
   *
   * <pre>
   * Product product = new Product();
   * product.setId(row.get("id", UUID.class));
   * product.setDescription(row.get("description", String.class));
   * ...
   * </pre>
   *
   * <p>It does not perform a query. Instead, those methods are intended for cases where you already
   * have a query result, and just need the conversion logic.
   *
   * <h3>Parameters</h3>
   *
   * The method must have a single parameter. The following types are allowed:
   *
   * <ul>
   *   <li>{@link GettableByName} or one of its subtypes (the most likely candidates are {@link Row}
   *       and {@link UdtValue}).
   *   <li>{@link ResultSet}.
   *   <li>{@link AsyncResultSet}.
   * </ul>
   *
   * The data must match the target entity: the generated code will try to extract every mapped
   * property, and fail if one is missing.
   *
   * <h3>Return type</h3>
   *
   * The method can return:
   *
   * <ul>
   *   <li>a single entity instance. If the argument is a result set type, the generated code will
   *       extract the first row and convert it, or return {@code null} if the result set is empty.
   *       <pre>
   * &#64;GetEntity
   * Product asProduct(Row row);
   *
   * &#64;GetEntity
   * Product firstRowAsProduct(ResultSet resultSet);
   *       </pre>
   *   <li>a {@link PagingIterable} of an entity class. In that case, the type of the parameter
   *       <b>must</b> be {@link ResultSet}. Each row in the result set will be converted into an
   *       entity instance.
   *       <pre>
   * &#64;GetEntity
   * PagingIterable&lt;Product&gt; asProducts(ResultSet resultSet);
   *       </pre>
   *   <li>a {@link MappedAsyncPagingIterable} of an entity class. In that case, the type of the
   *       parameter <b>must</b> be {@link AsyncResultSet}. Each row in the result set will be
   *       converted into an entity instance.
   *       <pre>
   * &#64;GetEntity
   * MappedAsyncPagingIterable&lt;Product&gt; asProducts(AsyncResultSet resultSet);
   *       </pre>
   * </ul>
   *
   * If the return type doesn't match the parameter type (for example {@link PagingIterable} for
   * {@link AsyncResultSet}), the mapper processor will issue a compile-time error.
   */
  @Target(ElementType.METHOD)
  @Retention(RetentionPolicy.RUNTIME)
  public @interface GetEntity {
  
    /**
     * Whether to tolerate missing columns in the source data structure.
     *
     * <p>If {@code false} (the default), then the source must contain a matching column for every
     * property in the entity definition, <em>including computed ones</em>. If such a column is not
     * found, an {@link IllegalArgumentException} will be thrown.
     *
     * <p>If {@code true}, the mapper will operate on a best-effort basis and attempt to read all
     * entity properties that have a matching column in the source, leaving unmatched properties
     * untouched. Beware that this may result in a partially-populated entity instance.
     */
    boolean lenient() default false;
  }
  