org.springframework.data.cassandra.core.cql.CassandraAccessor Maven / Gradle / Ivy
Show all versions of spring-data-cassandra Show documentation
/*
* Copyright 2013-2018 the original author or 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 org.springframework.data.cassandra.core.cql;
import java.util.Map;
import java.util.Optional;
import java.util.stream.StreamSupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.dao.DataAccessException;
import org.springframework.data.cassandra.SessionFactory;
import org.springframework.data.cassandra.core.cql.session.DefaultSessionFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import com.datastax.driver.core.ConsistencyLevel;
import com.datastax.driver.core.PreparedStatement;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.Statement;
import com.datastax.driver.core.exceptions.DriverException;
import com.datastax.driver.core.policies.RetryPolicy;
import com.datastax.driver.core.querybuilder.QueryBuilder;
/**
* {@link CassandraAccessor} provides access to a Cassandra {@link SessionFactory} and the
* {@link CassandraExceptionTranslator}.
*
* Classes providing a higher abstraction level usually extend {@link CassandraAccessor} to provide a richer set of
* functionality on top of a {@link SessionFactory} using {@link Session}.
*
* @author David Webb
* @author Mark Paluch
* @author John Blum
* @see org.springframework.beans.factory.InitializingBean
* @see com.datastax.driver.core.Session
*/
public class CassandraAccessor implements InitializingBean {
/**
* Placeholder for default values.
*/
private static final Statement DEFAULTS = QueryBuilder.select().from("DEFAULT");
/** Logger available to subclasses */
protected final Logger logger = LoggerFactory.getLogger(getClass());
private CqlExceptionTranslator exceptionTranslator = new CassandraExceptionTranslator();
/**
* If this variable is set to a non-negative value, it will be used for setting the {@code fetchSize} property on
* statements used for query processing.
*/
private int fetchSize = -1;
/**
* If this variable is set to a value, it will be used for setting the {@code consistencyLevel} property on statements
* used for query processing.
*/
private @Nullable com.datastax.driver.core.ConsistencyLevel consistencyLevel;
/**
* If this variable is set to a value, it will be used for setting the {@code retryPolicy} property on statements used
* for query processing.
*/
private @Nullable com.datastax.driver.core.policies.RetryPolicy retryPolicy;
private @Nullable SessionFactory sessionFactory;
/**
* Ensures the Cassandra {@link Session} and exception translator has been propertly set.
*/
@Override
public void afterPropertiesSet() {
Assert.state(sessionFactory != null, "SessionFactory must not be null");
}
/**
* Set the consistency level for this template. Consistency level defines the number of nodes involved into query
* processing. Relaxed consistency level settings use fewer nodes but eventual consistency is more likely to occur
* while a higher consistency level involves more nodes to obtain results with a higher consistency guarantee.
*
* @see Statement#setConsistencyLevel(ConsistencyLevel)
* @see RetryPolicy
*/
public void setConsistencyLevel(@Nullable ConsistencyLevel consistencyLevel) {
this.consistencyLevel = consistencyLevel;
}
/**
* @return the {@link ConsistencyLevel} specified for this template.
*/
@Nullable
public ConsistencyLevel getConsistencyLevel() {
return this.consistencyLevel;
}
/**
* Sets the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's
* Exception Hierarchy.
*
* @param exceptionTranslator exception translator to set; must not be {@literal null}.
* @see CqlExceptionTranslator
*/
public void setExceptionTranslator(CqlExceptionTranslator exceptionTranslator) {
Assert.notNull(exceptionTranslator, "CQLExceptionTranslator must not be null");
this.exceptionTranslator = exceptionTranslator;
}
/**
* Return the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's
* Exception Hierarchy.
*
* @return the Cassandra exception translator.
* @see CqlExceptionTranslator
*/
public CqlExceptionTranslator getExceptionTranslator() {
return this.exceptionTranslator;
}
/**
* Set the fetch size for this template. This is important for processing large result sets: Setting this higher than
* the default value will increase processing speed at the cost of memory consumption; setting this lower can avoid
* transferring row data that will never be read by the application. Default is -1, indicating to use the CQL driver's
* default configuration (i.e. to not pass a specific fetch size setting on to the driver).
*
* @see Statement#setFetchSize(int)
*/
public void setFetchSize(int fetchSize) {
this.fetchSize = fetchSize;
}
/**
* @return the fetch size specified for this template.
*/
public int getFetchSize() {
return this.fetchSize;
}
/**
* Set the retry policy for this template. This is important for defining behavior when a request fails.
*
* @see Statement#setRetryPolicy(RetryPolicy)
* @see RetryPolicy
*/
public void setRetryPolicy(@Nullable RetryPolicy retryPolicy) {
this.retryPolicy = retryPolicy;
}
/**
* @return the {@link RetryPolicy} specified for this template.
*/
@Nullable
public RetryPolicy getRetryPolicy() {
return this.retryPolicy;
}
/**
* Sets the Cassandra {@link Session} used by this template to perform Cassandra data access operations. The
* {@code session} will replace the current {@link #getSessionFactory()} with {@link DefaultSessionFactory}.
*
* @param session Cassandra {@link Session} used by this template, must not be{@literal null}.
* @see com.datastax.driver.core.Session
* @see DefaultSessionFactory
*/
public void setSession(Session session) {
Assert.notNull(session, "Session must not be null");
setSessionFactory(new DefaultSessionFactory(session));
}
/**
* Returns the Cassandra {@link Session} from {@link SessionFactory} used by this template to perform Cassandra data
* access operations.
*
* @return the Cassandra {@link Session} used by this template.
* @see com.datastax.driver.core.Session
* @deprecated since 2.0. This class uses a {@link SessionFactory} to dispatch CQL calls amongst different
* {@link Session}s during its lifecycle.
*/
@Deprecated
public Session getSession() {
Assert.state(getSessionFactory() != null, "SessionFactory was not properly initialized");
return getSessionFactory().getSession();
}
/**
* Sets the Cassandra {@link SessionFactory} used by this template to perform Cassandra data access operations.
*
* @param sessionFactory Cassandra {@link Session} used by this template. Must not be{@literal null}.
* @since 2.0
* @see com.datastax.driver.core.Session
*/
public void setSessionFactory(SessionFactory sessionFactory) {
Assert.notNull(sessionFactory, "SessionFactory must not be null");
this.sessionFactory = sessionFactory;
}
/**
* Returns the Cassandra {@link SessionFactory} used by this template to perform Cassandra data access operations.
*
* @return the Cassandra {@link SessionFactory} used by this template.
* @since 2.0
* @see SessionFactory
*/
@Nullable
public SessionFactory getSessionFactory() {
return this.sessionFactory;
}
/**
* Prepare the given CQL Statement (or {@link com.datastax.driver.core.PreparedStatement}), applying statement
* settings such as retry policy and consistency level.
*
* @param statement the CQL Statement to prepare
* @see #setRetryPolicy(RetryPolicy)
* @see #setConsistencyLevel(ConsistencyLevel)
*/
protected T applyStatementSettings(T statement) {
ConsistencyLevel consistencyLevel = getConsistencyLevel();
if (consistencyLevel != null) {
statement.setConsistencyLevel(consistencyLevel);
}
RetryPolicy retryPolicy = getRetryPolicy();
if (retryPolicy != null) {
statement.setRetryPolicy(retryPolicy);
}
return statement;
}
/**
* Prepare the given CQL Statement (or {@link com.datastax.driver.core.PreparedStatement}), applying statement
* settings such as fetch size, retry policy, and consistency level.
*
* @param statement the CQL Statement to prepare
* @see #setFetchSize(int)
* @see #setRetryPolicy(RetryPolicy)
* @see #setConsistencyLevel(ConsistencyLevel)
*/
protected T applyStatementSettings(T statement) {
ConsistencyLevel consistencyLevel = getConsistencyLevel();
if (consistencyLevel != null && statement.getConsistencyLevel() == DEFAULTS.getConsistencyLevel()) {
statement.setConsistencyLevel(consistencyLevel);
}
int fetchSize = getFetchSize();
if (fetchSize != -1 && statement.getFetchSize() == DEFAULTS.getFetchSize()) {
statement.setFetchSize(fetchSize);
}
RetryPolicy retryPolicy = getRetryPolicy();
if (retryPolicy != null && statement.getRetryPolicy() == DEFAULTS.getRetryPolicy()) {
statement.setRetryPolicy(retryPolicy);
}
return statement;
}
/**
* Translate the given {@link DriverException} into a generic {@link DataAccessException}.
*
* The returned {@link DataAccessException} is supposed to contain the original {@code DriverException} as root cause.
* However, client code may not generally rely on this due to {@link DataAccessException}s possibly being caused by
* other resource APIs as well. That said, a {@code getRootCause() instanceof DataAccessException} check (and
* subsequent cast) is considered reliable when expecting Cassandra-based access to have happened.
*
* @param ex the offending {@link DriverException}
* @return the DataAccessException, wrapping the {@code DriverException}
* @see Consistent
* exception hierarchy
* @see DataAccessException
*/
@Nullable
protected DataAccessException translateExceptionIfPossible(DriverException ex) {
Assert.notNull(ex, "DriverException must not be null");
return getExceptionTranslator().translateExceptionIfPossible(ex);
}
/**
* Translate the given {@link DriverException} into a generic {@link DataAccessException}.
*
* The returned {@link DataAccessException} is supposed to contain the original {@code DriverException} as root cause.
* However, client code may not generally rely on this due to {@link DataAccessException}s possibly being caused by
* other resource APIs as well. That said, a {@code getRootCause() instanceof DataAccessException} check (and
* subsequent cast) is considered reliable when expecting Cassandra-based access to have happened.
*
* @param task readable text describing the task being attempted
* @param cql CQL query or update that caused the problem (may be {@literal null})
* @param ex the offending {@link DriverException}
* @return the DataAccessException, wrapping the {@code DriverException}
* @see org.springframework.dao.DataAccessException#getRootCause()
* @see Consistent
* exception hierarchy
*/
protected DataAccessException translate(String task, @Nullable String cql, DriverException ex) {
Assert.notNull(ex, "DriverException must not be null");
return getExceptionTranslator().translate(task, cql, ex);
}
/**
* Create a new arg-based PreparedStatementSetter using the args passed in. By default, we'll create an
* {@link ArgumentPreparedStatementBinder}. This method allows for the creation to be overridden by subclasses.
*
* @param args object array with arguments
* @return the new {@link PreparedStatementBinder} to use
*/
protected PreparedStatementBinder newPreparedStatementBinder(Object[] args) {
return new ArgumentPreparedStatementBinder(args);
}
/**
* Constructs a new instance of the {@link ResultSetExtractor} initialized with and adapting the given
* {@link RowCallbackHandler}.
*
* @param rowCallbackHandler {@link RowCallbackHandler} to adapt as a {@link ResultSetExtractor}.
* @return a {@link ResultSetExtractor} implementation adapting an instance of the {@link RowCallbackHandler}.
* @see AsyncCqlTemplate.RowCallbackHandlerResultSetExtractor
* @see ResultSetExtractor
* @see RowCallbackHandler
*/
protected RowCallbackHandlerResultSetExtractor newResultSetExtractor(RowCallbackHandler rowCallbackHandler) {
return new RowCallbackHandlerResultSetExtractor(rowCallbackHandler);
}
/**
* Constructs a new instance of the {@link ResultSetExtractor} initialized with and adapting the given
* {@link RowMapper}.
*
* @param rowMapper {@link RowMapper} to adapt as a {@link ResultSetExtractor}.
* @return a {@link ResultSetExtractor} implementation adapting an instance of the {@link RowMapper}.
* @see ResultSetExtractor
* @see RowMapper
* @see RowMapperResultSetExtractor
*/
protected RowMapperResultSetExtractor newResultSetExtractor(RowMapper rowMapper) {
return new RowMapperResultSetExtractor<>(rowMapper);
}
/**
* Constructs a new instance of the {@link ResultSetExtractor} initialized with and adapting the given
* {@link RowMapper}.
*
* @param rowMapper {@link RowMapper} to adapt as a {@link ResultSetExtractor}.
* @param rowsExpected number of expected rows in the {@link ResultSet}.
* @return a {@link ResultSetExtractor} implementation adapting an instance of the {@link RowMapper}.
* @see ResultSetExtractor
* @see RowMapper
* @see RowMapperResultSetExtractor
*/
protected RowMapperResultSetExtractor newResultSetExtractor(RowMapper rowMapper, int rowsExpected) {
return new RowMapperResultSetExtractor<>(rowMapper, rowsExpected);
}
/**
* Create a new RowMapper for reading columns as key-value pairs.
*
* @return the RowMapper to use
* @see ColumnMapRowMapper
*/
protected RowMapper