HibernateTransactionManager lazily acquires JDBC Connection

Aligned with HibernateJpaDialect, using ConnectionHandle as functional interface now. Also, LazyConnectionDataSourceProxy supports Connection holdability as applied by HibernateTransactionManager, for use with prepareConnection=true.

Issue: SPR-17216
This commit is contained in:
Juergen Hoeller
2018-08-31 12:40:04 +02:00
parent a689daadf9
commit 78cad0fdd3
8 changed files with 76 additions and 69 deletions

View File

@@ -197,9 +197,16 @@ public class HibernateTransactionManager extends AbstractPlatformTransactionMana
* manager needs to work on the underlying target DataSource. If there's
* nevertheless a TransactionAwareDataSourceProxy passed in, it will be
* unwrapped to extract its target DataSource.
* <p><b>NOTE: For scenarios with many transactions that just read data from
* Hibernate's cache (and do not actually access the database), consider using
* a {@link org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy}
* for the actual target DataSource. Alternatively, consider switching
* {@link #setPrepareConnection "prepareConnection"} to {@code false}.</b>
* In both cases, this transaction manager will not eagerly acquire a
* JDBC Connection for each Hibernate Session anymore (as of Spring 5.1).
* @see #setAutodetectDataSource
* @see TransactionAwareDataSourceProxy
* @see DataSourceUtils
* @see org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy
* @see org.springframework.jdbc.core.JdbcTemplate
*/
public void setDataSource(@Nullable DataSource dataSource) {
@@ -462,33 +469,37 @@ public class HibernateTransactionManager extends AbstractPlatformTransactionMana
session = txObject.getSessionHolder().getSession();
if (this.prepareConnection && isSameConnectionForEntireSession(session)) {
// We're allowed to change the transaction settings of the JDBC Connection.
if (logger.isDebugEnabled()) {
logger.debug("Preparing JDBC Connection of Hibernate Session [" + session + "]");
}
Connection con = ((SessionImplementor) session).connection();
Integer previousIsolationLevel = DataSourceUtils.prepareConnectionForTransaction(con, definition);
txObject.setPreviousIsolationLevel(previousIsolationLevel);
if (this.allowResultAccessAfterCompletion && !txObject.isNewSession()) {
int currentHoldability = con.getHoldability();
if (currentHoldability != ResultSet.HOLD_CURSORS_OVER_COMMIT) {
txObject.setPreviousHoldability(currentHoldability);
con.setHoldability(ResultSet.HOLD_CURSORS_OVER_COMMIT);
boolean holdabilityNeeded = this.allowResultAccessAfterCompletion && !txObject.isNewSession();
boolean isolationLevelNeeded = (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT);
if (holdabilityNeeded || isolationLevelNeeded || definition.isReadOnly()) {
if (this.prepareConnection && isSameConnectionForEntireSession(session)) {
// We're allowed to change the transaction settings of the JDBC Connection.
if (logger.isDebugEnabled()) {
logger.debug("Preparing JDBC Connection of Hibernate Session [" + session + "]");
}
Connection con = ((SessionImplementor) session).connection();
Integer previousIsolationLevel = DataSourceUtils.prepareConnectionForTransaction(con, definition);
txObject.setPreviousIsolationLevel(previousIsolationLevel);
if (this.allowResultAccessAfterCompletion && !txObject.isNewSession()) {
int currentHoldability = con.getHoldability();
if (currentHoldability != ResultSet.HOLD_CURSORS_OVER_COMMIT) {
txObject.setPreviousHoldability(currentHoldability);
con.setHoldability(ResultSet.HOLD_CURSORS_OVER_COMMIT);
}
}
}
}
else {
// Not allowed to change the transaction settings of the JDBC Connection.
if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
// We should set a specific isolation level but are not allowed to...
throw new InvalidIsolationLevelException(
"HibernateTransactionManager is not allowed to support custom isolation levels: " +
"make sure that its 'prepareConnection' flag is on (the default) and that the " +
"Hibernate connection release mode is set to 'on_close' (the default for JDBC).");
}
if (logger.isDebugEnabled()) {
logger.debug("Not preparing JDBC Connection of Hibernate Session [" + session + "]");
else {
// Not allowed to change the transaction settings of the JDBC Connection.
if (isolationLevelNeeded) {
// We should set a specific isolation level but are not allowed to...
throw new InvalidIsolationLevelException(
"HibernateTransactionManager is not allowed to support custom isolation levels: " +
"make sure that its 'prepareConnection' flag is on (the default) and that the " +
"Hibernate connection release mode is set to 'on_close' (the default for JDBC).");
}
if (logger.isDebugEnabled()) {
logger.debug("Not preparing JDBC Connection of Hibernate Session [" + session + "]");
}
}
}
@@ -529,13 +540,13 @@ public class HibernateTransactionManager extends AbstractPlatformTransactionMana
// Register the Hibernate Session's JDBC Connection for the DataSource, if set.
if (getDataSource() != null) {
Connection con = ((SessionImplementor) session).connection();
ConnectionHolder conHolder = new ConnectionHolder(con);
SessionImplementor sessionImpl = (SessionImplementor) session;
ConnectionHolder conHolder = new ConnectionHolder(sessionImpl::connection);
if (timeout != TransactionDefinition.TIMEOUT_DEFAULT) {
conHolder.setTimeoutInSeconds(timeout);
}
if (logger.isDebugEnabled()) {
logger.debug("Exposing Hibernate transaction as JDBC transaction [" + con + "]");
logger.debug("Exposing Hibernate transaction as JDBC [" + conHolder.getConnectionHandle() + "]");
}
TransactionSynchronizationManager.bindResource(getDataSource(), conHolder);
txObject.setConnectionHolder(conHolder);

View File

@@ -416,7 +416,7 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
conHolder.setTimeoutInSeconds(timeoutToUse);
}
if (logger.isDebugEnabled()) {
logger.debug("Exposing JPA transaction as JDBC transaction [" + conHandle + "]");
logger.debug("Exposing JPA transaction as JDBC [" + conHandle + "]");
}
TransactionSynchronizationManager.bindResource(getDataSource(), conHolder);
txObject.setConnectionHolder(conHolder);

View File

@@ -131,10 +131,6 @@ public class EclipseLinkJpaDialect extends DefaultJpaDialect {
}
return this.connection;
}
@Override
public void releaseConnection(Connection con) {
}
}
}

View File

@@ -75,7 +75,7 @@ import org.springframework.util.ReflectionUtils;
/**
* {@link org.springframework.orm.jpa.JpaDialect} implementation for
* Hibernate EntityManager. Developed against Hibernate 5.0/5.1/5.2.
* Hibernate EntityManager. Developed against Hibernate 5.1/5.2/5.3.
*
* @author Juergen Hoeller
* @author Costin Leau
@@ -119,10 +119,8 @@ public class HibernateJpaDialect extends DefaultJpaDialect {
* Hibernate Session, that is, whether to apply a transaction-specific
* isolation level and/or the transaction's read-only flag to the underlying
* JDBC Connection.
* <p>Default is "true" on Hibernate EntityManager 4.x (with its 'on-close'
* connection release mode.
* <p>If you turn this flag off, JPA transaction management will not support
* per-transaction isolation levels anymore. It will not call
* <p>Default is "true". If you turn this flag off, JPA transaction management
* will not support per-transaction isolation levels anymore. It will not call
* {@code Connection.setReadOnly(true)} for read-only transactions anymore either.
* If this flag is turned off, no cleanup of a JDBC Connection is required after
* a transaction, since no Connection settings will get modified.
@@ -415,10 +413,6 @@ public class HibernateJpaDialect extends DefaultJpaDialect {
return doGetConnection(this.session);
}
@Override
public void releaseConnection(Connection con) {
}
public static Connection doGetConnection(Session session) {
try {
Method methodToUse = connectionMethodToUse;

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@@ -41,7 +41,7 @@ import org.springframework.lang.Nullable;
/**
* {@link org.springframework.orm.jpa.JpaVendorAdapter} implementation for Hibernate
* EntityManager. Developed and tested against Hibernate 5.0, 5.1 and 5.2;
* EntityManager. Developed and tested against Hibernate 5.0, 5.1, 5.2 and 5.3;
* backwards-compatible with Hibernate 4.3 at runtime on a best-effort basis.
*
* <p>Exposes Hibernate's persistence provider and EntityManager extension interface,