org.dellroad.stuff.schema
Class SpringSQLSchemaUpdater

java.lang.Object
  org.dellroad.stuff.schema.AbstractSchemaUpdater<DataSource,Connection>
      org.dellroad.stuff.schema.SQLSchemaUpdater
          org.dellroad.stuff.schema.SpringSQLSchemaUpdater

All Implemented Interfaces:

BeanFactoryAware, InitializingBean

public class SpringSQLSchemaUpdater
extends SQLSchemaUpdater
implements BeanFactoryAware, InitializingBean

SQLSchemaUpdater optimized for use with Spring.

• apply() is overridden so Spring DataAccessExceptions are thrown.
• indicatesUninitializedDatabase() is overridden to examine exceptions and more precisely using Spring's exception translation infrastructure to filter out false positives.
• getOrderingTieBreaker() is overridden to break ties by ordering updates in the same order as they are defined in the bean factory.
• This class implements InitializingBean and verifies all required properties are set.
• If no updates are explicitly configured, then all SpringSQLSchemaUpdates found in the containing bean factory are automatically configured.

An example of how this class can be combined with custom XML to define an updater, all its updates, and a SchemaUpdatingDataSource that automatically updates the database schema:

  <beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:dellroad-stuff="http://dellroad-stuff.googlecode.com/schema/dellroad-stuff"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="
      http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
      http://dellroad-stuff.googlecode.com/schema/dellroad-stuff
        http://dellroad-stuff.googlecode.com/svn/wiki/schemas/dellroad-stuff-1.0.xsd">

     <!-- DataSource that automatically updates the database schema -->
     <bean id="dataSource" class="org.dellroad.stuff.schema.SchemaUpdatingDataSource"
       p:dataSource-ref="realDataSource" p:schemaUpdater-ref="schemaUpdater"/>

     <!--
          Database updater bean. This is used on first access to the DataSource above. Notes:
            - "databaseInitialization" is used to initialize the schema (first time only)
            - "updateTableInitialization" is used to initialize the update table (first time only)
            - In this example, we just use dellroad-stuff's update table initialization for MySQL
            - The <dellroad-stuff:sql-update> beans below will be auto-detected
     -->
     <bean id="schemaUpdater" class="org.dellroad.stuff.schema.SpringSQLSchemaUpdater">
         <property name="databaseInitialization">
             <dellroad-stuff:sql resource="classpath:databaseInit.sql"/>
         </property>
         <property name="updateTableInitialization">
             <dellroad-stuff:sql resource="classpath:org/dellroad/stuff/schema/updateTable-mysql.sql"/>
         </property>
     </bean>

      <!-- Schema update to add the 'phone' column to the 'User' table -->
      <dellroad-stuff:sql-update id="addPhone">ALTER TABLE User ADD phone VARCHAR(64)</dellroad-stuff:sql-update>

      <!-- Schema update to run some complicated external SQL script -->
      <dellroad-stuff:sql-update id="majorChanges" depends-on="addPhone" resource="classpath:majorChanges.sql"/>

      <!-- Multiple SQL commands that will be automatically separated into distinct updates -->
      <dellroad-stuff:sql-update id="renameColumn">
          ALTER TABLE User ADD newName VARCHAR(64);
          ALTER TABLE User SET newName = oldName;
          ALTER TABLE User DROP oldName;
      </dellroad-stuff:sql-update>

      <!-- Add more schema updates over time as needed and everything just works... -->

  </beans>
 

In the case no schema updates are explicitly configured, it is required that this updater and all of its schema updates are defined in the same ListableBeanFactory.

Field Summary

Fields inherited from class org.dellroad.stuff.schema.SQLSchemaUpdater

DEFAULT_UPDATE_TABLE_NAME, DEFAULT_UPDATE_TABLE_NAME_COLUMN, DEFAULT_UPDATE_TABLE_TIME_COLUMN

Fields inherited from class org.dellroad.stuff.schema.AbstractSchemaUpdater

log

Constructor Summary

SpringSQLSchemaUpdater()

Method Summary

void	afterPropertiesSet()
protected void	apply(Connection c, DatabaseAction<Connection> action) Apply a DatabaseAction to a Connection.
protected Comparator<SchemaUpdate<Connection>>	getOrderingTieBreaker() Get the preferred ordering of two updates that do not have any predecessor constraints (including implied indirect constraints) between them.
protected boolean	indicatesUninitializedDatabase(Connection c, SQLException e) Determine if an exception thrown during SQLSchemaUpdater.databaseNeedsInitialization(java.sql.Connection) is consistent with an uninitialized database.
void	setBeanFactory(BeanFactory beanFactory)
protected DataAccessException	translate(SQLException e, Connection c, String sql) Converts SQLExceptions into Spring DataAccessExceptions.

Methods inherited from class org.dellroad.stuff.schema.SQLSchemaUpdater

commitTransaction, databaseNeedsInitialization, getAppliedUpdateNames, getDatabaseInitialization, getUpdateTableInitialization, getUpdateTableName, getUpdateTableNameColumn, getUpdateTableTimeColumn, initializeAndUpdateDatabase, initializeDatabase, openTransaction, recordUpdateApplied, rollbackTransaction, setDatabaseInitialization, setUpdateTableInitialization, setUpdateTableName, setUpdateTableNameColumn, setUpdateTableTimeColumn

Methods inherited from class org.dellroad.stuff.schema.AbstractSchemaUpdater

applyInTransaction, generateMultiUpdateName, getUpdates, isIgnoreUnrecognizedUpdates, isValidUpdateName, setIgnoreUnrecognizedUpdates, setUpdates

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SpringSQLSchemaUpdater

public SpringSQLSchemaUpdater()

Method Detail

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Specified by:

afterPropertiesSet in interface InitializingBean

Throws:

Exception

setBeanFactory

public void setBeanFactory(BeanFactory beanFactory)

Specified by:

setBeanFactory in interface BeanFactoryAware

indicatesUninitializedDatabase

protected boolean indicatesUninitializedDatabase(Connection c,
                                                 SQLException e)
                                          throws SQLException

Determine if an exception thrown during SQLSchemaUpdater.databaseNeedsInitialization(java.sql.Connection) is consistent with an uninitialized database.

The implementation in SpringSQLSchemaUpdater looks for a BadSqlGrammarException.

Overrides:

indicatesUninitializedDatabase in class SQLSchemaUpdater

Parameters:

c - connection on which the exception occurred

e - exception thrown during database access in SQLSchemaUpdater.databaseNeedsInitialization(java.sql.Connection)

Throws:

SQLException - if an error occurs

See Also:

SQLSchemaUpdater.databaseNeedsInitialization(java.sql.Connection)

apply

protected void apply(Connection c,
                     DatabaseAction<Connection> action)
              throws SQLException

Apply a DatabaseAction to a Connection.

The implementation in SQLSchemaUpdater invokes the action and delegates to translate() to convert any SQLException thrown.

Overrides:

apply in class SQLSchemaUpdater

Throws:

SQLException - if an error occurs attempting to translate a thrown SQLException

DataAccessException - if an error occurs accessing the database

See Also:

translate()

translate

protected DataAccessException translate(SQLException e,
                                        Connection c,
                                        String sql)
                                 throws SQLException

Converts SQLExceptions into Spring DataAccessExceptions.

Throws:

SQLException

getOrderingTieBreaker

protected Comparator<SchemaUpdate<Connection>> getOrderingTieBreaker()

Get the preferred ordering of two updates that do not have any predecessor constraints (including implied indirect constraints) between them.

In the case no schema updates are explicitly configured, the Comparator returned by the implementation in SpringSQLSchemaUpdater sorts updates in the same order that they appear in the containing ListableBeanFactory. Otherwise, the superclass method is used.

Overrides:

getOrderingTieBreaker in class AbstractSchemaUpdater<DataSource,Connection>

Returns:

a Comparator that sorts incomparable updates in the order they should be applied