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/**
 * Copyright Microsoft Corporation
 * 
 * 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.microsoft.azure.storage.table;

import java.util.Date;
import java.util.HashMap;

import com.microsoft.azure.storage.OperationContext;
import com.microsoft.azure.storage.StorageException;

/**
 * An interface required for table entity types. The {@link TableEntity} interface declares getter and setter methods
 * for the common entity properties, and writeEntity and readEntity methods for serialization
 * and deserialization of all entity properties using a property map. Create classes implementing {@link TableEntity} to
 * customize property storage, retrieval, serialization and deserialization, and to provide additional custom logic for
 * a table entity.
 * 

* The Storage client library includes two implementations of {@link TableEntity} that provide for simple property * access and serialization: *

* {@link DynamicTableEntity} implements {@link TableEntity} and provides a simple property map to store and retrieve * properties. Use a {@link DynamicTableEntity} for simple access to entity properties when only a subset of properties * are returned (for example, by a select clause in a query), or for when your query can return multiple entity types * with different properties. You can also use this type to perform bulk table updates of heterogeneous entities without * losing property information. *

* {@link TableServiceEntity} is an implementation of {@link TableEntity} that uses reflection-based serialization and * deserialization behavior in its writeEntity and readEntity methods. * {@link TableServiceEntity}-derived classes with methods that follow a convention for types and naming are serialized * and deserialized automatically. *

* Any class that implements {@link TableEntity} can take advantage of the automatic reflection-based serialization and * deserialization behavior in {@link TableServiceEntity} by invoking the static methods * TableServiceEntity.readEntityWithReflection in readEntity and * TableServiceEntity.writeEntityWithReflection in writeEntity. The class must provide methods * that follow the type and naming convention to be serialized and deserialized automatically. When both a getter method * and setter method are found for a given property name and data type, then the appropriate method is invoked * automatically to serialize or deserialize the data. The reflection code looks for getter and setter methods in pairs * of the form *

* public type getPropertyName() { ... } *

* and *

* public void setPropertyName(type parameter) { ... } *

* where PropertyName is a property name for the table entity, and type is a Java type compatible with * the EDM data type of the property. See the table in the class description for {@link TableServiceEntity} for a map of * property types to their Java equivalents. The {@link StoreAs} annotation may be applied with a name * attribute to specify a property name for reflection on getter and setter methods that do not follow the property name * convention. Method names and the name attribute of {@link StoreAs} annotations are case sensitive for * matching property names with reflection. Use the {@link Ignore} annotation to prevent methods from being used by * reflection for automatic serialization and deserialization. Note that the names "PartitionKey", "RowKey", * "Timestamp", and "Etag" are reserved and will be ignored if set with the {@link StoreAs} annotation in a subclass * that uses the reflection methods. *

* * @see TableServiceEntity * @see DynamicTableEntity */ public interface TableEntity { /** * Gets the ETag value to verify for the entity. This value is used to determine if the table entity has changed * since it was last read from Microsoft Azure storage. The client cannot update this value on the service. * * @return * A String which represents the ETag for the entity. */ public String getEtag(); /** * Gets the PartitionKey value for the entity. * * @return * A String which represents the PartitionKey value for the entity. */ public String getPartitionKey(); /** * Gets the RowKey value for the entity. * * @return * A String which represents the RowKey value for the entity. */ public String getRowKey(); /** * Gets the Timestamp for the entity. The server manages the value of Timestamp, which cannot be modified. * * @return * A java.util.Date object which represents the Timestamp value for the entity. */ public Date getTimestamp(); /** * Populates an instance of the object implementing {@link TableEntity} using the specified properties parameter, * which represents a map of String property names to {@link EntityProperty} data typed values. * * @param properties * The java.util.HashMap of String to {@link EntityProperty} data typed values * to use to populate the table entity instance. * @param opContext * An {@link OperationContext} object used to track the execution of the operation. * * @throws StorageException * If an error occurs during the operation. */ public void readEntity(HashMap properties, OperationContext opContext) throws StorageException; /** * Sets the ETag value to verify for the entity. This value is used to determine if the table entity has changed * since it was last read from Microsoft Azure storage. The client cannot update this value on the service. * * @param etag * A String which specifies the ETag to set for the entity. */ public void setEtag(String etag); /** * Sets the PartitionKey value for the entity. * * @param partitionKey * A String which specifies the PartitionKey value to set for the entity. */ public void setPartitionKey(String partitionKey); /** * Sets the RowKey value for the entity. * * @param rowKey * A String which specifies the RowKey value to set for the entity. */ public void setRowKey(String rowKey); /** * Sets the Timestamp value for the entity. Note that timestamp is a read-only property on the service and should * not be set by the user. * * @param timeStamp * A java.util.Date which specifies the Timestamp value to set for the entity. */ public void setTimestamp(Date timeStamp); /** * Returns a map of String property names to {@link EntityProperty} data typed values * that represents the serialized content of the table entity instance. * * @param opContext * An {@link OperationContext} object used to track the execution of the operation. * * @return * A java.util.HashMap of String property names to {@link EntityProperty} data * typed values representing the properties of the table entity. * * @throws StorageException * If an error occurs during the operation. */ public HashMap writeEntity(OperationContext opContext) throws StorageException; }





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