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HSQLDB example source code file (TextTable.java)
The HSQLDB TextTable.java source code/* Copyright (c) 2001-2008, The HSQL Development Group * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the HSQL Development Group nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG, * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package org.hsqldb; import org.hsqldb.lib.FileUtil; import org.hsqldb.lib.StringConverter; import org.hsqldb.persist.TextCache; // tony_lai@users 20020820 - patch 595099 - user define PK name /** * Subclass of Table to handle TEXT data source. <p> * * Extends Table to provide the notion of an SQL base table object whose * data is read from and written to a text format data file. * * @author sqlbob@users (RMP) * @version 1.8.0 */ class TextTable extends org.hsqldb.Table { private String dataSource = ""; private boolean isReversed = false; private boolean isConnected = false; /** * Constructs a new TextTable from the given arguments. * * @param db the owning database * @param name the table's HsqlName * @param type (normal or temp text table) * @param sessionid the id of the owning session (for temp table) * @exception HsqlException Description of the Exception */ TextTable(Database db, HsqlNameManager.HsqlName name, int type) throws HsqlException { super(db, name, type); } /** * common handling for all errors during <code>connect */ private void onConnectError(Session session) { if (cache != null) { try { cache.close(false); } catch (HsqlException ex) {} } cache = null; clearAllRows(session); } public boolean isConnected() { return isConnected; } /** * connects to the data source */ public void connect(Session session) throws HsqlException { connect(session, isReadOnly); } /** * connects to the data source */ private void connect(Session session, boolean withReadOnlyData) throws HsqlException { // Open new cache: if ((dataSource.length() == 0) || isConnected) { // nothing to do return; } try { cache = database.logger.openTextCache(this, dataSource, withReadOnlyData, isReversed); // read and insert all the rows from the source file CachedRow row = null; int nextpos = 0; if (((TextCache) cache).ignoreFirst) { nextpos += ((TextCache) cache).readHeaderLine(); } while (true) { row = (CachedRow) rowStore.get(nextpos); if (row == null) { break; } nextpos = row.getPos() + row.getStorageSize(); row.setNewNodes(); insertFromTextSource(row); } } catch (HsqlException e) { int linenumber = cache == null ? 0 : ((TextCache) cache) .getLineNumber(); onConnectError(session); // everything is in order here. // At this point table should either have a valid (old) data // source and cache or have an empty source and null cache. throw Trace.error(Trace.TEXT_FILE, new Object[] { new Integer(linenumber), e.getMessage() }); } catch (java.lang.RuntimeException t) { int linenumber = cache == null ? 0 : ((TextCache) cache) .getLineNumber(); onConnectError(session); throw Trace.error(Trace.TEXT_FILE, new Object[] { new Integer(linenumber), t.getClass().getName() + ": " + t.getMessage() }); } isConnected = true; setIsReadOnly(withReadOnlyData); } /** * disconnects from the data source */ public void disconnect(Session session) throws HsqlException { // Close old cache: database.logger.closeTextCache(this); cache = null; clearAllRows(session); isConnected = false; } /** * This method does some of the work involved with managing the creation * and openning of the cache, the rest is done in Log.java and * TextCache.java. * * Better clarification of the role of the methods is needed. */ private void openCache(Session session, String dataSourceNew, boolean isReversedNew, boolean isReadOnlyNew) throws HsqlException { if (dataSourceNew == null) { dataSourceNew = ""; } disconnect(session); dataSource = dataSourceNew; isReversed = (isReversedNew && dataSource.length() > 0); connect(session, isReadOnlyNew); } /** * High level command to assign a data source to the table definition. * Reassigns only if the data source or direction has changed. */ protected void setDataSource(Session session, String dataSourceNew, boolean isReversedNew, boolean newFile) throws HsqlException { if (getTableType() == Table.TEMP_TEXT_TABLE) { ; } else { session.checkAdmin(); } dataSourceNew = dataSourceNew.trim(); if (newFile && FileUtil.getDefaultInstance().exists(dataSourceNew)) { throw Trace.error(Trace.TEXT_SOURCE_EXISTS, dataSourceNew); } //-- Open if descending, direction changed, file changed, or not connected currently if (isReversedNew || (isReversedNew != isReversed) || !dataSource.equals(dataSourceNew) || !isConnected) { openCache(session, dataSourceNew, isReversedNew, isReadOnly); } if (isReversed) { setIsReadOnly(true); } } protected String getDataSource() { return dataSource; } protected boolean isDescDataSource() { return isReversed; } public void setHeader(String header) throws HsqlException { if (cache != null && ((TextCache) cache).ignoreFirst) { ((TextCache) cache).setHeader(header); return; } throw Trace.error(Trace.TEXT_TABLE_HEADER); } public String getHeader() { String header = cache == null ? null : ((TextCache) cache).getHeader(); return header == null ? null : StringConverter.toQuotedString(header, '\"', true); } /** * Used by INSERT, DELETE, UPDATE operations. This class will return * a more appropriate message when there is no data source. */ void checkDataReadOnly() throws HsqlException { if (dataSource.length() == 0) { throw Trace.error(Trace.UNKNOWN_DATA_SOURCE); } if (isDataReadOnly()) { throw Trace.error(Trace.DATA_IS_READONLY); } } public boolean isDataReadOnly() { return !isConnected() || super.isDataReadOnly(); } void setDataReadOnly(boolean value) throws HsqlException { if (isReversed && value == false) { throw Trace.error(Trace.DATA_IS_READONLY); } openCache(null, dataSource, isReversed, value); setIsReadOnly(value); } boolean isIndexCached() { return false; } protected Table duplicate() throws HsqlException { return new TextTable(database, tableName, getTableType()); } void drop() throws HsqlException { openCache(null, "", false, false); } void setIndexRoots(String s) throws HsqlException { // do nothing } } Other HSQLDB examples (source code examples)Here is a short list of links related to this HSQLDB TextTable.java source code file: |
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