Java tutorial
package org.apache.ddlutils.task; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ import java.security.AccessController; import java.security.PrivilegedAction; import java.util.ArrayList; import java.util.Iterator; import java.util.Properties; import org.apache.commons.dbcp.BasicDataSource; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.ddlutils.Platform; import org.apache.ddlutils.model.Database; import org.apache.log4j.Level; import org.apache.log4j.LogManager; import org.apache.log4j.PropertyConfigurator; import org.apache.tools.ant.AntClassLoader; import org.apache.tools.ant.BuildException; import org.apache.tools.ant.Task; /** * Base class for DdlUtils Ant tasks that operate on a database. * * @version $Revision: 289996 $ * @ant.task ignore="true" */ public abstract class DatabaseTaskBase extends Task { /** The log. */ protected Log _log; /** The platform configuration. */ private PlatformConfiguration _platformConf = new PlatformConfiguration(); /** The sub tasks to execute. */ private ArrayList _commands = new ArrayList(); /** Whether to use simple logging (that the Ant task configures itself via the {@link #_verbosity} setting. */ private boolean _simpleLogging = true; /** The verbosity of the task's debug output. */ private VerbosityLevel _verbosity = null; /** * Specifies whether simple logging (configured by the task via the <code>verbosity</code> * setting) shall be used, or whether logging is configured outside of the task * (e.g. via a log4j properties file). * * @param simpleLogging Whether to use simple logging or not * @ant.not-required Per default, simple logging is enabled. */ public void setSimpleLogging(boolean simpleLogging) { _simpleLogging = simpleLogging; } /** * Specifies the verbosity of the task's debug output. * * @param level The verbosity level * @ant.not-required Default is <code>INFO</code>. */ public void setVerbosity(VerbosityLevel level) { _verbosity = level; } /** * Returns the database type. * * @return The database type */ public String getDatabaseType() { return _platformConf.getDatabaseType(); } /** * Specifies the database type. You should only need to set this if DdlUtils is not able to * derive the setting from the name of the used jdbc driver or the jdbc connection url. * If you have to specify this, please post your jdbc driver and connection url combo * to the user mailing list so that DdlUtils can be enhanced to support this combo.<br/> * Valid values are currently:<br/><code>axion, cloudscape, db2, derby, firebird, hsqldb, interbase, * maxdb, mckoi, mssql, mysql, mysql5, oracle, oracle9, oracle10, postgresql, sapdb, sybase</code> * * @param type The database type * @ant.not-required Per default, DdlUtils tries to determine the database type via JDBC. */ public void setDatabaseType(String type) { if ((type != null) && (type.length() > 0)) { _platformConf.setDatabaseType(type); } } /** * Returns the data source. * * @return The data source */ public BasicDataSource getDataSource() { return _platformConf.getDataSource(); } /** * Adds the data source to use for accessing the database. * * @param dataSource The data source */ public void addConfiguredDatabase(BasicDataSource dataSource) { _platformConf.setDataSource(dataSource); } /** * Specifies a pattern that defines which database catalogs to use. For some * more info on catalog patterns and JDBC, see * <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/sql/DatabaseMetaData.html">java.sql.DatabaseMetaData</a>. * * @param catalogPattern The catalog pattern * @ant.not-required Per default no specific catalog is used. */ public void setCatalogPattern(String catalogPattern) { if ((catalogPattern != null) && (catalogPattern.length() > 0)) { _platformConf.setCatalogPattern(catalogPattern); } } /** * Specifies a pattern that defines which database schemas to use. For some * more info on schema patterns and JDBC, see * <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/sql/DatabaseMetaData.html">java.sql.DatabaseMetaData</a>. * * @param schemaPattern The schema pattern * @ant.not-required Per default no specific schema is used. */ public void setSchemaPattern(String schemaPattern) { if ((schemaPattern != null) && (schemaPattern.length() > 0)) { _platformConf.setSchemaPattern(schemaPattern); } } /** * Determines whether delimited SQL identifiers shall be used (the default). * * @return <code>true</code> if delimited SQL identifiers shall be used */ public boolean isUseDelimitedSqlIdentifiers() { return _platformConf.isUseDelimitedSqlIdentifiers(); } /** * Specifies whether DdlUtils shall use delimited (quoted) identifiers (such as table and column * names). Most databases convert undelimited identifiers to uppercase and ignore the case of * identifiers when performing any SQL command. Undelimited identifiers also cannot be reserved * words and can only contain alphanumerical characters and the underscore.<br/> * These limitations do not exist for delimited identifiers where identifiers have to be enclosed * in double quotes. Delimited identifiers can contain unicode characters, and even reserved * words can be used as identifiers. Please be aware though, that they always have to enclosed * in double quotes, and that the case of the identifier will be important in every SQL command * executed against the database. * * @param useDelimitedSqlIdentifiers <code>true</code> if delimited SQL identifiers shall be used * @ant.not-required Default is <code>false</code>. */ public void setUseDelimitedSqlIdentifiers(boolean useDelimitedSqlIdentifiers) { _platformConf.setUseDelimitedSqlIdentifiers(useDelimitedSqlIdentifiers); } /** * Determines whether a table's foreign keys read from a live database * shall be sorted alphabetically. Is <code>false</code> by default. * * @return <code>true</code> if the foreign keys shall be sorted */ public boolean isSortForeignKeys() { return _platformConf.isSortForeignKeys(); } /** * Specifies whether DdlUtils shall sort the foreign keys of a table read from a live database or * leave them in the order in which they are returned by the database/JDBC driver. Note that * the sort is case sensitive only if delimited identifier mode is on * (<code>useDelimitedSqlIdentifiers</code> is set to <code>true</code>). * * @param sortForeignKeys <code>true</code> if the foreign keys shall be sorted * @ant.not-required Default is <code>false</code>. */ public void setSortForeignKeys(boolean sortForeignKeys) { _platformConf.setSortForeignKeys(sortForeignKeys); } /** * Determines whether the database shall be shut down after the task has finished. * * @return <code>true</code> if the database shall be shut down */ public boolean isShutdownDatabase() { return _platformConf.isShutdownDatabase(); } /** * Specifies whether DdlUtils shall shut down the database after the task has finished. * This is mostly useful for embedded databases. * * @param shutdownDatabase <code>true</code> if the database shall be shut down * @ant.not-required Default is <code>false</code>. */ public void setShutdownDatabase(boolean shutdownDatabase) { _platformConf.setShutdownDatabase(shutdownDatabase); } /** * Adds a command. * * @param command The command */ protected void addCommand(Command command) { _commands.add(command); } /** * Determines whether there are commands to perform. * * @return <code>true</code> if there are commands */ protected boolean hasCommands() { return !_commands.isEmpty(); } /** * Returns the commands. * * @return The commands */ protected Iterator getCommands() { return _commands.iterator(); } /** * Creates the platform configuration. * * @return The platform configuration */ protected PlatformConfiguration getPlatformConfiguration() { return _platformConf; } /** * Creates the platform for the configured database. * * @return The platform */ protected Platform getPlatform() { return _platformConf.getPlatform(); } /** * Reads the database model on which the commands will work. * * @return The database model */ protected abstract Database readModel(); /** * Initializes the logging. */ private void initLogging() { if (_simpleLogging) { // For Ant, we're forcing DdlUtils to do logging via log4j to the console Properties props = new Properties(); String level = (_verbosity == null ? Level.INFO.toString() : _verbosity.getValue()).toUpperCase(); props.setProperty("log4j.rootCategory", level + ",A"); props.setProperty("log4j.appender.A", "org.apache.log4j.ConsoleAppender"); props.setProperty("log4j.appender.A.layout", "org.apache.log4j.PatternLayout"); props.setProperty("log4j.appender.A.layout.ConversionPattern", "%m%n"); // we don't want debug logging from Digester props.setProperty("log4j.logger.org.apache.commons", "WARN"); LogManager.resetConfiguration(); PropertyConfigurator.configure(props); } _log = LogFactory.getLog(getClass()); } /** * Executes the commands. * * @param model The database model */ protected void executeCommands(Database model) throws BuildException { for (Iterator it = getCommands(); it.hasNext();) { Command cmd = (Command) it.next(); if (cmd.isRequiringModel() && (model == null)) { throw new BuildException("No database model specified"); } if (cmd instanceof DatabaseCommand) { ((DatabaseCommand) cmd).setPlatformConfiguration(_platformConf); } cmd.execute(this, model); } } /** * {@inheritDoc} */ public void execute() throws BuildException { initLogging(); if (!hasCommands()) { _log.info("No sub tasks specified, so there is nothing to do."); return; } ClassLoader sysClassLoader = (ClassLoader) AccessController.doPrivileged(new PrivilegedAction() { public Object run() { try { ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader(); AntClassLoader newClassLoader = new AntClassLoader(getClass().getClassLoader(), true); // we're changing the thread classloader so that we can access resources // from the classpath used to load this task's class Thread.currentThread().setContextClassLoader(newClassLoader); return contextClassLoader; } catch (SecurityException ex) { throw new BuildException("Could not change the context clas loader", ex); } } }); try { executeCommands(readModel()); } finally { if ((getDataSource() != null) && isShutdownDatabase()) { getPlatform().shutdownDatabase(); } // rollback of our classloader change Thread.currentThread().setContextClassLoader(sysClassLoader); } } }