Incorrect exception type throw by spring jdbc

[samratdhillon]

Affects: 5.1.9 and previous versions

spring-jdbc uses SQLErrorCodeSQLExceptionTranslator with mapping file /spring-jdbc/src/main/resources/org/springframework/jdbc/support/sql-error-codes.xml to map between vendor error codes and relevant Exceptions.

For example, if underlying database is mysql then vendor error code 1062 gets mapped to DuplicateKeyException.

However to be able to identify the vendor itself spring-jdbc invokes JdbcUtils#extractDatabaseMetaData(dataSource, "getDatabaseProductName") which then calls JdbcUtils.extractDatabaseMetaData(DataSource, DatabaseMetaDataCallback). The call to JdbcUtils#extractDatabaseMetaData creates a connection using the datasource and then retrieves the database vendor (although vendor name could be available from the driver itself and creating connection may not be necessary). If however creating the connection fails for whatever reason, then SQLErrorCodesFactory will never try to re-initialize SQLErrorCodes and then for the entire life cycle of the application Spring will fall back to the SQLExceptionSubclassTranslator.

This causes Spring to throw inconsistent exceptions. For example, if mysql throws 1062 and SQLErrorCodeSQLExceptionTranslator is not properly initialized due to connection issue, then SQLExceptionSubclassTranslator will throw DataIntegrityViolationException instead of DuplicateKeyException, and this will continue until the application is restarted.

Ideally Spring should keep on retrying to discover vendor name if JdbcUtils#extractDatabaseMetaData fails. This can be very annoying in a cluster where one node with properly initialized SQLErrorCodes will throw a different exception from a node which is falling back to SQLExceptionSubclassTranslator.

[snicoll]

@samratdhillon thanks for the PR. We don't need both an issue and a PR as one supersedes the other. Let's continue this conversation on the PR.

Closing in favour of PR #23676