com.microsoft.windowsazure.services.table.client.QueryTableOperation Maven / Gradle / Ivy
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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.windowsazure.services.table.client;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.text.ParseException;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import com.microsoft.windowsazure.services.core.storage.OperationContext;
import com.microsoft.windowsazure.services.core.storage.StorageException;
import com.microsoft.windowsazure.services.core.storage.utils.Utility;
import com.microsoft.windowsazure.services.core.storage.utils.implementation.ExecutionEngine;
import com.microsoft.windowsazure.services.core.storage.utils.implementation.StorageOperation;
/**
* A class that extends {@link TableOperation} to implement a query to retrieve a single table entity. To execute a
* {@link QueryTableOperation} instance, call the execute method on a {@link CloudTableClient} instance.
* This operation can be executed directly or as part of a {@link TableBatchOperation}. If the
* {@link QueryTableOperation} returns an entity result, it is stored in the corresponding {@link TableResult} returned
* by the execute method.
*/
public class QueryTableOperation extends TableOperation {
private EntityResolver resolver;
private Class clazzType;
private String partitionKey;
private String rowKey;
/**
* Default constructor.
*/
protected QueryTableOperation() {
super(null, TableOperationType.RETRIEVE);
}
/**
* Constructs a {@link QueryTableOperation} instance to retrieve a single table entity with the specified partition
* key and row key.
*
* @param partitionKey
* A String containing the PartitionKey value for the entity.
* @param rowKey
* A String containing the RowKey value for the entity.
*/
QueryTableOperation(final String partitionKey, final String rowKey) {
super(null, TableOperationType.RETRIEVE);
Utility.assertNotNull("partitionKey", partitionKey);
this.partitionKey = partitionKey;
this.rowKey = rowKey;
}
/**
* Gets the PartitionKey value for the entity to retrieve.
*
* @return
* A String containing the PartitionKey value for the entity.
*/
public String getPartitionKey() {
return this.partitionKey;
}
/**
* Gets the resolver to project the entity retrieved as a particular type.
*
* @return
* The {@link EntityResolver} instance.
*/
public EntityResolver getResolver() {
return this.resolver;
}
/**
* Gets the RowKey value for the entity to retrieve.
*
* @return
* A String containing the RowKey value for the entity.
*/
public String getRowKey() {
return this.rowKey;
}
/**
* Reserved for internal use. Gets the class type of the entity returned by the query.
*
* @return
* The java.lang.Class implementing {@link TableEntity} that represents the entity type for the
* query.
*/
protected Class getClazzType() {
return this.clazzType;
}
/**
* Reserved for internal use. Parses the query table operation response into a {@link TableResult} to return.
*
* @param xmlr
* An XMLStreamReader containing the response to the query operation.
* @param httpStatusCode
* The HTTP status code returned from the operation request.
* @param etagFromHeader
* The String containing the Etag returned with the operation response.
* @param opContext
* An {@link OperationContext} object that represents the context for the current operation.
*
* @return
* The {@link TableResult} representing the result of the query operation.
*
* @throws XMLStreamException
* if an error occurs accessing the XMLStreamReader.
* @throws ParseException
* if an error occurs in parsing the response.
* @throws InstantiationException
* if an error occurs in object construction.
* @throws IllegalAccessException
* if an error occurs in reflection on an object type.
* @throws StorageException
* if an error occurs in the storage operation.
*/
@Override
protected TableResult parseResponse(final XMLStreamReader xmlr, final int httpStatusCode,
final String etagFromHeader, final OperationContext opContext) throws XMLStreamException, ParseException,
InstantiationException, IllegalAccessException, StorageException {
return AtomPubParser.parseSingleOpResponse(xmlr, httpStatusCode, this.getClazzType(), this.getResolver(),
opContext);
}
/**
* Reserved for internal use. Performs a retrieve operation on the specified table, using the specified
* {@link TableRequestOptions} and {@link OperationContext}.
*
* This method will invoke the Storage Service REST API to execute this table operation, using the Table service
* endpoint and storage account credentials in the {@link CloudTableClient} object.
*
* @param client
* A {@link CloudTableClient} instance specifying the Table service endpoint and storage account
* credentials to use.
* @param tableName
* A String containing the name of the table to query.
* @param options
* A {@link TableRequestOptions} object that specifies execution options such as retry policy and timeout
* settings for the operation.
* @param opContext
* An {@link OperationContext} object for tracking the current operation.
*
* @return
* A {@link TableResult} containing the results of executing the query operation.
*
* @throws StorageException
* if an error occurs in the storage operation.
*/
protected TableResult performRetrieve(final CloudTableClient client, final String tableName,
final TableRequestOptions options, final OperationContext opContext) throws StorageException {
final boolean isTableEntry = TableConstants.TABLES_SERVICE_TABLES_NAME.equals(tableName);
if (this.getClazzType() != null) {
Utility.checkNullaryCtor(this.getClazzType());
}
else {
Utility.assertNotNull("Query requires a valid class type or resolver.", this.getResolver());
}
final StorageOperation impl = new StorageOperation(
options) {
@Override
public TableResult execute(final CloudTableClient client, final QueryTableOperation operation,
final OperationContext opContext) throws Exception {
final HttpURLConnection request = TableRequest.query(client.getTransformedEndPoint(opContext),
tableName, generateRequestIdentity(isTableEntry, operation.getPartitionKey(), false),
options.getTimeoutIntervalInMs(), null/* Query Builder */, null/* Continuation Token */,
options, opContext);
this.setConnection(request);
this.signTableRequest(client, request, -1L, opContext);
ExecutionEngine.processRequest(request, opContext, this.getResult());
if (this.getResult().getStatusCode() == HttpURLConnection.HTTP_OK) {
// Parse response for updates
InputStream inStream = request.getInputStream();
final XMLStreamReader xmlr = Utility.createXMLStreamReaderFromStream(inStream);
TableResult res = null;
res = AtomPubParser.parseSingleOpResponse(xmlr, this.getResult().getStatusCode(),
operation.getClazzType(), operation.getResolver(), opContext);
return res;
}
else if (this.getResult().getStatusCode() == HttpURLConnection.HTTP_NOT_FOUND) {
// Empty result
return new TableResult(this.getResult().getStatusCode());
}
else {
this.setNonExceptionedRetryableFailure(true);
return null;
}
}
};
return ExecutionEngine.executeWithRetry(client, this, impl, options.getRetryPolicyFactory(), opContext);
}
/**
* Reserved for internal use. Sets the class type of the entity returned by the query.
*
* @param clazzType
* The java.lang.Class implementing {@link TableEntity} that represents the entity type for
* the query.
*/
protected void setClazzType(final Class clazzType) {
Utility.assertNotNull("clazzType", clazzType);
Utility.checkNullaryCtor(clazzType);
this.clazzType = clazzType;
}
/**
* Reserved for internal use. Sets the PartitionKey value for the entity to retrieve.
*
* @param partitionKey
* A String containing the PartitionKey value for the entity.
*/
protected void setPartitionKey(final String partitionKey) {
this.partitionKey = partitionKey;
}
/**
* Reserved for internal use. Sets the resolver to project the entity retrieved as a particular type.
*
* @param resolver
* The {@link EntityResolver} instance to use.
*/
protected void setResolver(final EntityResolver resolver) {
Utility.assertNotNull("Query requires a valid class type or resolver.", resolver);
this.resolver = resolver;
}
/**
* Reserved for internal use. Sets the RowKey value for the entity to retrieve.
*
* @param rowKey
* A String containing the RowKey value for the entity.
*/
protected void setRowKey(final String rowKey) {
this.rowKey = rowKey;
}
}