From c5771bc7c80bdea79b62b2ed0ab8e0222773bc45 Mon Sep 17 00:00:00 2001 From: Juergen Hoeller Date: Wed, 5 Jul 2023 12:51:10 +0200 Subject: [PATCH] Discuss JdbcTransactionManager vs DataSourceTransactionManager Includes doc update for 6.0 default exception translation etc. Closes gh-30802 --- .../modules/ROOT/pages/data-access/dao.adoc | 8 +-- .../ROOT/pages/data-access/jdbc/advanced.adoc | 10 +-- .../pages/data-access/jdbc/connections.adoc | 64 ++++++++++++------- .../ROOT/pages/data-access/jdbc/core.adoc | 36 +++++++---- .../ROOT/pages/data-access/jdbc/packages.adoc | 24 +++---- .../ROOT/pages/data-access/orm/jpa.adoc | 2 +- .../modules/ROOT/pages/data-access/r2dbc.adoc | 18 ++---- .../transaction/declarative/annotations.adoc | 7 +- .../PlatformTransactionManager.java | 21 +++--- 9 files changed, 105 insertions(+), 85 deletions(-) diff --git a/framework-docs/modules/ROOT/pages/data-access/dao.adoc b/framework-docs/modules/ROOT/pages/data-access/dao.adoc index 4c2844e9549..9ca9666f541 100644 --- a/framework-docs/modules/ROOT/pages/data-access/dao.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/dao.adoc @@ -151,10 +151,10 @@ Kotlin:: ---- ====== -The last example we show here is for typical JDBC support. You could have the -`DataSource` injected into an initialization method or a constructor, where you would create a -`JdbcTemplate` and other data access support classes (such as `SimpleJdbcCall` and others) by using -this `DataSource`. The following example autowires a `DataSource`: +The last example we show here is for typical JDBC support. You could have the `DataSource` +injected into an initialization method or a constructor, where you would create a `JdbcTemplate` +and other data access support classes (such as `SimpleJdbcCall` and others) by using this +`DataSource`. The following example autowires a `DataSource`: [tabs] ====== diff --git a/framework-docs/modules/ROOT/pages/data-access/jdbc/advanced.adoc b/framework-docs/modules/ROOT/pages/data-access/jdbc/advanced.adoc index ce43becb612..04533c9cb82 100644 --- a/framework-docs/modules/ROOT/pages/data-access/jdbc/advanced.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/jdbc/advanced.adoc @@ -9,13 +9,13 @@ to the database. [[jdbc-batch-classic]] == Basic Batch Operations with `JdbcTemplate` -You accomplish `JdbcTemplate` batch processing by implementing two methods of a special -interface, `BatchPreparedStatementSetter`, and passing that implementation in as the second parameter +You accomplish `JdbcTemplate` batch processing by implementing two methods of a special interface, +`BatchPreparedStatementSetter`, and passing that implementation in as the second parameter in your `batchUpdate` method call. You can use the `getBatchSize` method to provide the size of the current batch. You can use the `setValues` method to set the values for the parameters of -the prepared statement. This method is called the number of times that you -specified in the `getBatchSize` call. The following example updates the `t_actor` table -based on entries in a list, and the entire list is used as the batch: +the prepared statement. This method is called the number of times that you specified in the +`getBatchSize` call. The following example updates the `t_actor` table based on entries in a list, +and the entire list is used as the batch: [tabs] ====== diff --git a/framework-docs/modules/ROOT/pages/data-access/jdbc/connections.adoc b/framework-docs/modules/ROOT/pages/data-access/jdbc/connections.adoc index e8e60ac527f..7ebb4a44a68 100644 --- a/framework-docs/modules/ROOT/pages/data-access/jdbc/connections.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/jdbc/connections.adoc @@ -10,7 +10,7 @@ This section covers: * xref:data-access/jdbc/connections.adoc#jdbc-SingleConnectionDataSource[Using `SingleConnectionDataSource`] * xref:data-access/jdbc/connections.adoc#jdbc-DriverManagerDataSource[Using `DriverManagerDataSource`] * xref:data-access/jdbc/connections.adoc#jdbc-TransactionAwareDataSourceProxy[Using `TransactionAwareDataSourceProxy`] -* xref:data-access/jdbc/connections.adoc#jdbc-DataSourceTransactionManager[Using `DataSourceTransactionManager`] +* xref:data-access/jdbc/connections.adoc#jdbc-DataSourceTransactionManager[Using `DataSourceTransactionManager` / `JdbcTransactionManager`] [[jdbc-datasource]] @@ -125,8 +125,12 @@ The following example shows C3P0 configuration: == Using `DataSourceUtils` The `DataSourceUtils` class is a convenient and powerful helper class that provides -`static` methods to obtain connections from JNDI and close connections if necessary. It -supports thread-bound connections with, for example, `DataSourceTransactionManager`. +`static` methods to obtain connections from JNDI and close connections if necessary. +It supports a thread-bound JDBC `Connection` with `DataSourceTransactionManager` but +also with `JtaTransactionManager` and `JpaTransactionManager`. + +Note that `JdbcTemplate` implies `DataSourceUtils` connection access, using it +behind every JDBC operation, implicitly participating in an ongoing transaction. [[jdbc-SmartDataSource]] @@ -165,7 +169,6 @@ In contrast to `DriverManagerDataSource`, it reuses the same connection all the avoiding excessive creation of physical connections. - [[jdbc-DriverManagerDataSource]] == Using `DriverManagerDataSource` @@ -201,29 +204,44 @@ javadoc for more details. [[jdbc-DataSourceTransactionManager]] -== Using `DataSourceTransactionManager` +== Using `DataSourceTransactionManager` / `JdbcTransactionManager` The `DataSourceTransactionManager` class is a `PlatformTransactionManager` -implementation for single JDBC data sources. It binds a JDBC connection from the -specified data source to the currently executing thread, potentially allowing for one -thread connection per data source. +implementation for a single JDBC `DataSource`. It binds a JDBC `Connection` +from the specified `DataSource` to the currently executing thread, potentially +allowing for one thread-bound `Connection` per `DataSource`. -Application code is required to retrieve the JDBC connection through -`DataSourceUtils.getConnection(DataSource)` instead of Jakarta EE's standard +Application code is required to retrieve the JDBC `Connection` through +`DataSourceUtils.getConnection(DataSource)` instead of Java EE's standard `DataSource.getConnection`. It throws unchecked `org.springframework.dao` exceptions -instead of checked `SQLExceptions`. All framework classes (such as `JdbcTemplate`) use this -strategy implicitly. If not used with this transaction manager, the lookup strategy -behaves exactly like the common one. Thus, it can be used in any case. - -The `DataSourceTransactionManager` class supports custom isolation levels and timeouts -that get applied as appropriate JDBC statement query timeouts. To support the latter, -application code must either use `JdbcTemplate` or call the -`DataSourceUtils.applyTransactionTimeout(..)` method for each created statement. - -You can use this implementation instead of `JtaTransactionManager` in the single-resource -case, as it does not require the container to support JTA. Switching between -both is just a matter of configuration, provided you stick to the required connection lookup -pattern. JTA does not support custom isolation levels. +instead of checked `SQLExceptions`. All framework classes (such as `JdbcTemplate`) use +this strategy implicitly. If not used with a transaction manager, the lookup strategy +behaves exactly like `DataSource.getConnection` and can therefore be used in any case. + +The `DataSourceTransactionManager` class supports savepoints (`PROPAGATION_NESTED`), +custom isolation levels, and timeouts that get applied as appropriate JDBC statement +query timeouts. To support the latter, application code must either use `JdbcTemplate` or +call the `DataSourceUtils.applyTransactionTimeout(..)` method for each created statement. + +You can use `DataSourceTransactionManager` instead of `JtaTransactionManager` in the +single-resource case, as it does not require the container to support a JTA transaction +coordinator. Switching between these transaction managers is just a matter of configuration, +provided you stick to the required connection lookup pattern. Note that JTA does not support +savepoints or custom isolation levels and has a different timeout mechanism but otherwise +exposes similar behavior in terms of JDBC resources and JDBC commit/rollback management. + +NOTE: As of 5.3, Spring provides an extended `JdbcTransactionManager` variant which adds +exception translation capabilities on commit/rollback (aligned with `JdbcTemplate`). +Where `DataSourceTransactionManager` will only ever throw `TransactionSystemException` +(analogous to JTA), `JdbcTransactionManager` translates database locking failures etc to +corresponding `DataAccessException` subclasses. Note that application code needs to be +prepared for such exceptions, not exclusively expecting `TransactionSystemException`. +In scenarios where that is the case, `JdbcTransactionManager` is the recommended choice. + +In terms of exception behavior, `JdbcTransactionManager` is roughly equivalent to +`JpaTransactionManager` and also to `R2dbcTransactionManager`, serving as an immediate +companion/replacement for each other. `DataSourceTransactionManager` on the other hand +is equivalent to `JtaTransactionManager` and can serve as a direct replacement there. diff --git a/framework-docs/modules/ROOT/pages/data-access/jdbc/core.adoc b/framework-docs/modules/ROOT/pages/data-access/jdbc/core.adoc index 31bbecce2f2..4112a918a47 100644 --- a/framework-docs/modules/ROOT/pages/data-access/jdbc/core.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/jdbc/core.adoc @@ -718,12 +718,22 @@ See also xref:data-access/jdbc/core.adoc#jdbc-JdbcTemplate-idioms[`JdbcTemplate` between ``SQLException``s and Spring's own `org.springframework.dao.DataAccessException`, which is agnostic in regard to data access strategy. Implementations can be generic (for example, using SQLState codes for JDBC) or proprietary (for example, using Oracle error -codes) for greater precision. +codes) for greater precision. This exception translation mechanism is used behind the +the common `JdbcTemplate` and `JdbcTransactionManager` entry points which do not +propagate `SQLException` but rather `DataAccessException`. + +NOTE: As of 6.0, the default exception translator is `SQLExceptionSubclassTranslator`, +detecting JDBC 4 `SQLException` subclasses with a few extra checks, and with a fallback +to `SQLState` introspection through `SQLStateSQLExceptionTranslator`. This is usually +sufficient for common database access and does not require vendor-specific detection. +For backwards compatibility, consider using `SQLErrorCodeSQLExceptionTranslator` as +described below, potentially with custom error code mappings. `SQLErrorCodeSQLExceptionTranslator` is the implementation of `SQLExceptionTranslator` -that is used by default. This implementation uses specific vendor codes. It is more -precise than the `SQLState` implementation. The error code translations are based on -codes held in a JavaBean type class called `SQLErrorCodes`. This class is created and +that is used by default when a file named `sql-error-codes.xml` is present in the root +of the classpath. This implementation uses specific vendor codes. It is more precise than +`SQLState` or `SQLException` subclass translation. The error code translations are based +on codes held in a JavaBean type class called `SQLErrorCodes`. This class is created and populated by an `SQLErrorCodesFactory`, which (as the name suggests) is a factory for creating `SQLErrorCodes` based on the contents of a configuration file named `sql-error-codes.xml`. This file is populated with vendor codes and based on the @@ -744,8 +754,8 @@ The `SQLErrorCodeSQLExceptionTranslator` applies matching rules in the following translator. If this translation is not available, the next fallback translator is the `SQLStateSQLExceptionTranslator`. -NOTE: The `SQLErrorCodesFactory` is used by default to define `Error` codes and custom exception -translations. They are looked up in a file named `sql-error-codes.xml` from the +NOTE: The `SQLErrorCodesFactory` is used by default to define error codes and custom +exception translations. They are looked up in a file named `sql-error-codes.xml` from the classpath, and the matching `SQLErrorCodes` instance is located based on the database name from the database metadata of the database in use. @@ -784,12 +794,12 @@ Kotlin:: ---- ====== -In the preceding example, the specific error code (`-12345`) is translated, while other errors are -left to be translated by the default translator implementation. To use this custom -translator, you must pass it to the `JdbcTemplate` through the method -`setExceptionTranslator`, and you must use this `JdbcTemplate` for all of the data access -processing where this translator is needed. The following example shows how you can use this custom -translator: +In the preceding example, the specific error code (`-12345`) is translated while +other errors are left to be translated by the default translator implementation. +To use this custom translator, you must pass it to the `JdbcTemplate` through the +method `setExceptionTranslator`, and you must use this `JdbcTemplate` for all of the +data access processing where this translator is needed. The following example shows +how you can use this custom translator: [tabs] ====== @@ -800,7 +810,6 @@ Java:: private JdbcTemplate jdbcTemplate; public void setDataSource(DataSource dataSource) { - // create a JdbcTemplate and set data source this.jdbcTemplate = new JdbcTemplate(); this.jdbcTemplate.setDataSource(dataSource); @@ -809,7 +818,6 @@ Java:: CustomSQLErrorCodesTranslator tr = new CustomSQLErrorCodesTranslator(); tr.setDataSource(dataSource); this.jdbcTemplate.setExceptionTranslator(tr); - } public void updateShippingCharge(long orderId, long pct) { diff --git a/framework-docs/modules/ROOT/pages/data-access/jdbc/packages.adoc b/framework-docs/modules/ROOT/pages/data-access/jdbc/packages.adoc index e6719fec871..4eba396012b 100644 --- a/framework-docs/modules/ROOT/pages/data-access/jdbc/packages.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/jdbc/packages.adoc @@ -3,30 +3,30 @@ The Spring Framework's JDBC abstraction framework consists of four different packages: -* `core`: The `org.springframework.jdbc.core` package contains the `JdbcTemplate` class and its -various callback interfaces, plus a variety of related classes. A subpackage named -`org.springframework.jdbc.core.simple` contains the `SimpleJdbcInsert` and +* `core`: The `org.springframework.jdbc.core` package contains the `JdbcTemplate` class +and its various callback interfaces, plus a variety of related classes. A subpackage +named `org.springframework.jdbc.core.simple` contains the `SimpleJdbcInsert` and `SimpleJdbcCall` classes. Another subpackage named `org.springframework.jdbc.core.namedparam` contains the `NamedParameterJdbcTemplate` class and the related support classes. See xref:data-access/jdbc/core.adoc[Using the JDBC Core Classes to Control Basic JDBC Processing and Error Handling], xref:data-access/jdbc/advanced.adoc[JDBC Batch Operations], and xref:data-access/jdbc/simple.adoc[Simplifying JDBC Operations with the `SimpleJdbc` Classes]. -* `datasource`: The `org.springframework.jdbc.datasource` package contains a utility class for easy -`DataSource` access and various simple `DataSource` implementations that you can use for -testing and running unmodified JDBC code outside of a Jakarta EE container. A subpackage -named `org.springfamework.jdbc.datasource.embedded` provides support for creating +* `datasource`: The `org.springframework.jdbc.datasource` package contains a utility class +for easy `DataSource` access and various simple `DataSource` implementations that you can +use for testing and running unmodified JDBC code outside of a Jakarta EE container. A subpackage +named `org.springframework.jdbc.datasource.embedded` provides support for creating embedded databases by using Java database engines, such as HSQL, H2, and Derby. See xref:data-access/jdbc/connections.adoc[Controlling Database Connections] and xref:data-access/jdbc/embedded-database-support.adoc[Embedded Database Support]. -* `object`: The `org.springframework.jdbc.object` package contains classes that represent RDBMS -queries, updates, and stored procedures as thread-safe, reusable objects. See +* `object`: The `org.springframework.jdbc.object` package contains classes that represent +RDBMS queries, updates, and stored procedures as thread-safe, reusable objects. See xref:data-access/jdbc/object.adoc[Modeling JDBC Operations as Java Objects]. This approach is modeled by JDO, although objects returned by queries are naturally disconnected from the database. This higher-level of JDBC abstraction depends on the lower-level abstraction in the `org.springframework.jdbc.core` package. -* `support`: The `org.springframework.jdbc.support` package provides `SQLException` translation -functionality and some utility classes. Exceptions thrown during JDBC processing are -translated to exceptions defined in the `org.springframework.dao` package. This means +* `support`: The `org.springframework.jdbc.support` package provides `SQLException` +translation functionality and some utility classes. Exceptions thrown during JDBC processing +are translated to exceptions defined in the `org.springframework.dao` package. This means that code using the Spring JDBC abstraction layer does not need to implement JDBC or RDBMS-specific error handling. All translated exceptions are unchecked, which gives you the option of catching the exceptions from which you can recover while letting other diff --git a/framework-docs/modules/ROOT/pages/data-access/orm/jpa.adoc b/framework-docs/modules/ROOT/pages/data-access/orm/jpa.adoc index 0f60323febc..9dbf42a56d7 100644 --- a/framework-docs/modules/ROOT/pages/data-access/orm/jpa.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/orm/jpa.adoc @@ -495,7 +495,7 @@ features supported by Spring, usually in a vendor-specific manner: * Applying specific transaction semantics (such as custom isolation level or transaction timeout) * Retrieving the transactional JDBC `Connection` (for exposure to JDBC-based DAOs) -* Advanced translation of `PersistenceExceptions` to Spring `DataAccessExceptions` +* Advanced translation of `PersistenceException` to Spring's `DataAccessException` This is particularly valuable for special transaction semantics and for advanced translation of exception. The default implementation (`DefaultJpaDialect`) does diff --git a/framework-docs/modules/ROOT/pages/data-access/r2dbc.adoc b/framework-docs/modules/ROOT/pages/data-access/r2dbc.adoc index f5735720ad5..65e30ce8ae0 100644 --- a/framework-docs/modules/ROOT/pages/data-access/r2dbc.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/r2dbc.adoc @@ -718,19 +718,15 @@ javadoc for more details. === Using `R2dbcTransactionManager` The `R2dbcTransactionManager` class is a `ReactiveTransactionManager` implementation for -single R2DBC data sources. It binds an R2DBC connection from the specified connection factory -to the subscriber `Context`, potentially allowing for one subscriber connection for each -connection factory. +a single R2DBC `ConnectionFactory`. It binds an R2DBC `Connection` from the specified +`ConnectionFactory` to the subscriber `Context`, potentially allowing for one subscriber +`Connection` for each `ConnectionFactory`. -Application code is required to retrieve the R2DBC connection through +Application code is required to retrieve the R2DBC `Connection` through `ConnectionFactoryUtils.getConnection(ConnectionFactory)`, instead of R2DBC's standard -`ConnectionFactory.create()`. - -All framework classes (such as `DatabaseClient`) use this strategy implicitly. -If not used with this transaction manager, the lookup strategy behaves exactly like the common one. -Thus, it can be used in any case. - -The `R2dbcTransactionManager` class supports custom isolation levels that get applied to the connection. +`ConnectionFactory.create()`. All framework classes (such as `DatabaseClient`) use this +strategy implicitly. If not used with a transaction manager, the lookup strategy behaves +exactly like `ConnectionFactory.create()` and can therefore be used in any case. diff --git a/framework-docs/modules/ROOT/pages/data-access/transaction/declarative/annotations.adoc b/framework-docs/modules/ROOT/pages/data-access/transaction/declarative/annotations.adoc index a43d6e06fb4..8a762b791c5 100644 --- a/framework-docs/modules/ROOT/pages/data-access/transaction/declarative/annotations.adoc +++ b/framework-docs/modules/ROOT/pages/data-access/transaction/declarative/annotations.adoc @@ -124,7 +124,6 @@ In XML configuration, the `` tag provides similar conveni ---- <1> The line that makes the bean instance transactional. - TIP: You can omit the `transaction-manager` attribute in the `` tag if the bean name of the `TransactionManager` that you want to wire in has the name `transactionManager`. If the `TransactionManager` bean that you want to dependency-inject @@ -522,17 +521,17 @@ The following listing shows the bean declarations: ---- - + ... - + ... - + ... diff --git a/spring-tx/src/main/java/org/springframework/transaction/PlatformTransactionManager.java b/spring-tx/src/main/java/org/springframework/transaction/PlatformTransactionManager.java index f15e2f3700c..6122d0906d4 100644 --- a/spring-tx/src/main/java/org/springframework/transaction/PlatformTransactionManager.java +++ b/spring-tx/src/main/java/org/springframework/transaction/PlatformTransactionManager.java @@ -1,5 +1,5 @@ /* - * Copyright 2002-2020 the original author or authors. + * Copyright 2002-2023 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. @@ -31,10 +31,10 @@ import org.springframework.lang.Nullable; * template methods for specific states of the underlying transaction, * for example: begin, suspend, resume, commit. * - *

The default implementations of this strategy interface are - * {@link org.springframework.transaction.jta.JtaTransactionManager} and - * {@link org.springframework.jdbc.datasource.DataSourceTransactionManager}, - * which can serve as an implementation guide for other transaction strategies. + *

A classic implementation of this strategy interface is + * {@link org.springframework.transaction.jta.JtaTransactionManager}. However, + * in common single-resource scenarios, Spring's specific transaction managers + * for e.g. JDBC, JPA, JMS are preferred choices. * * @author Rod Johnson * @author Juergen Hoeller @@ -81,12 +81,9 @@ public interface PlatformTransactionManager extends TransactionManager { *

Note that when the commit call completes, no matter if normally or * throwing an exception, the transaction must be fully completed and * cleaned up. No rollback call should be expected in such a case. - *

If this method throws an exception other than a TransactionException, - * then some before-commit error caused the commit attempt to fail. For - * example, an O/R Mapping tool might have tried to flush changes to the - * database right before commit, with the resulting DataAccessException - * causing the transaction to fail. The original exception will be - * propagated to the caller of this commit method in such a case. + *

Depending on the concrete transaction manager setup, {@code commit} + * may propagate {@link org.springframework.dao.DataAccessException} as well, + * either from before-commit flushes or from the actual commit step. * @param status object returned by the {@code getTransaction} method * @throws UnexpectedRollbackException in case of an unexpected rollback * that the transaction coordinator initiated @@ -110,6 +107,8 @@ public interface PlatformTransactionManager extends TransactionManager { * The transaction will already have been completed and cleaned up when commit * returns, even in case of a commit exception. Consequently, a rollback call * after commit failure will lead to an IllegalTransactionStateException. + *

Depending on the concrete transaction manager setup, {@code rollback} + * may propagate {@link org.springframework.dao.DataAccessException} as well. * @param status object returned by the {@code getTransaction} method * @throws TransactionSystemException in case of rollback or system errors * (typically caused by fundamental resource failures)