| /* |
| * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.rowset.internal; |
| |
| import java.sql.*; |
| import javax.sql.*; |
| import java.util.*; |
| import java.io.*; |
| |
| import com.sun.rowset.*; |
| import javax.sql.rowset.*; |
| import javax.sql.rowset.spi.*; |
| |
| |
| /** |
| * The facility called on internally by the <code>RIOptimisticProvider</code> implementation to |
| * propagate changes back to the data source from which the rowset got its data. |
| * <P> |
| * A <code>CachedRowSetWriter</code> object, called a writer, has the public |
| * method <code>writeData</code> for writing modified data to the underlying data source. |
| * This method is invoked by the rowset internally and is never invoked directly by an application. |
| * A writer also has public methods for setting and getting |
| * the <code>CachedRowSetReader</code> object, called a reader, that is associated |
| * with the writer. The remainder of the methods in this class are private and |
| * are invoked internally, either directly or indirectly, by the method |
| * <code>writeData</code>. |
| * <P> |
| * Typically the <code>SyncFactory</code> manages the <code>RowSetReader</code> and |
| * the <code>RowSetWriter</code> implementations using <code>SyncProvider</code> objects. |
| * Standard JDBC RowSet implementations provide an object instance of this |
| * writer by invoking the <code>SyncProvider.getRowSetWriter()</code> method. |
| * |
| * @author Jonathan Bruce |
| * @see javax.sql.rowset.spi.SyncProvider |
| * @see javax.sql.rowset.spi.SyncFactory |
| * @see javax.sql.rowset.spi.SyncFactoryException |
| */ |
| public class CachedRowSetWriter implements TransactionalWriter, Serializable { |
| |
| /** |
| * The <code>Connection</code> object that this writer will use to make a |
| * connection to the data source to which it will write data. |
| * |
| */ |
| private transient Connection con; |
| |
| /** |
| * The SQL <code>SELECT</code> command that this writer will call |
| * internally. The method <code>initSQLStatements</code> builds this |
| * command by supplying the words "SELECT" and "FROM," and using |
| * metadata to get the table name and column names . |
| * |
| * @serial |
| */ |
| private String selectCmd; |
| |
| /** |
| * The SQL <code>UPDATE</code> command that this writer will call |
| * internally to write data to the rowset's underlying data source. |
| * The method <code>initSQLStatements</code> builds this <code>String</code> |
| * object. |
| * |
| * @serial |
| */ |
| private String updateCmd; |
| |
| /** |
| * The SQL <code>WHERE</code> clause the writer will use for update |
| * statements in the <code>PreparedStatement</code> object |
| * it sends to the underlying data source. |
| * |
| * @serial |
| */ |
| private String updateWhere; |
| |
| /** |
| * The SQL <code>DELETE</code> command that this writer will call |
| * internally to delete a row in the rowset's underlying data source. |
| * |
| * @serial |
| */ |
| private String deleteCmd; |
| |
| /** |
| * The SQL <code>WHERE</code> clause the writer will use for delete |
| * statements in the <code>PreparedStatement</code> object |
| * it sends to the underlying data source. |
| * |
| * @serial |
| */ |
| private String deleteWhere; |
| |
| /** |
| * The SQL <code>INSERT INTO</code> command that this writer will internally use |
| * to insert data into the rowset's underlying data source. The method |
| * <code>initSQLStatements</code> builds this command with a question |
| * mark parameter placeholder for each column in the rowset. |
| * |
| * @serial |
| */ |
| private String insertCmd; |
| |
| /** |
| * An array containing the column numbers of the columns that are |
| * needed to uniquely identify a row in the <code>CachedRowSet</code> object |
| * for which this <code>CachedRowSetWriter</code> object is the writer. |
| * |
| * @serial |
| */ |
| private int[] keyCols; |
| |
| /** |
| * An array of the parameters that should be used to set the parameter |
| * placeholders in a <code>PreparedStatement</code> object that this |
| * writer will execute. |
| * |
| * @serial |
| */ |
| private Object[] params; |
| |
| /** |
| * The <code>CachedRowSetReader</code> object that has been |
| * set as the reader for the <code>CachedRowSet</code> object |
| * for which this <code>CachedRowSetWriter</code> object is the writer. |
| * |
| * @serial |
| */ |
| private CachedRowSetReader reader; |
| |
| /** |
| * The <code>ResultSetMetaData</code> object that contains information |
| * about the columns in the <code>CachedRowSet</code> object |
| * for which this <code>CachedRowSetWriter</code> object is the writer. |
| * |
| * @serial |
| */ |
| private ResultSetMetaData callerMd; |
| |
| /** |
| * The number of columns in the <code>CachedRowSet</code> object |
| * for which this <code>CachedRowSetWriter</code> object is the writer. |
| * |
| * @serial |
| */ |
| private int callerColumnCount; |
| |
| /** |
| * This <code>CachedRowSet<code> will hold the conflicting values |
| * retrieved from the db and hold it. |
| */ |
| private CachedRowSetImpl crsResolve; |
| |
| /** |
| * This <code>ArrayList<code> will hold the values of SyncResolver.* |
| */ |
| private ArrayList status; |
| |
| /** |
| * This will check whether the same field value has changed both |
| * in database and CachedRowSet. |
| */ |
| private int iChangedValsInDbAndCRS; |
| |
| /** |
| * This will hold the number of cols for which the values have |
| * changed only in database. |
| */ |
| private int iChangedValsinDbOnly ; |
| |
| private JdbcRowSetResourceBundle resBundle; |
| |
| public CachedRowSetWriter() { |
| try { |
| resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle(); |
| } catch(IOException ioe) { |
| throw new RuntimeException(ioe); |
| } |
| } |
| |
| /** |
| * Propagates changes in the given <code>RowSet</code> object |
| * back to its underlying data source and returns <code>true</code> |
| * if successful. The writer will check to see if |
| * the data in the pre-modified rowset (the original values) differ |
| * from the data in the underlying data source. If data in the data |
| * source has been modified by someone else, there is a conflict, |
| * and in that case, the writer will not write to the data source. |
| * In other words, the writer uses an optimistic concurrency algorithm: |
| * It checks for conflicts before making changes rather than restricting |
| * access for concurrent users. |
| * <P> |
| * This method is called by the rowset internally when |
| * the application invokes the method <code>acceptChanges</code>. |
| * The <code>writeData</code> method in turn calls private methods that |
| * it defines internally. |
| * The following is a general summary of what the method |
| * <code>writeData</code> does, much of which is accomplished |
| * through calls to its own internal methods. |
| * <OL> |
| * <LI>Creates a <code>CachedRowSet</code> object from the given |
| * <code>RowSet</code> object |
| * <LI>Makes a connection with the data source |
| * <UL> |
| * <LI>Disables autocommit mode if it is not already disabled |
| * <LI>Sets the transaction isolation level to that of the rowset |
| * </UL> |
| * <LI>Checks to see if the reader has read new data since the writer |
| * was last called and, if so, calls the method |
| * <code>initSQLStatements</code> to initialize new SQL statements |
| * <UL> |
| * <LI>Builds new <code>SELECT</code>, <code>UPDATE</code>, |
| * <code>INSERT</code>, and <code>DELETE</code> statements |
| * <LI>Uses the <code>CachedRowSet</code> object's metadata to |
| * determine the table name, column names, and the columns |
| * that make up the primary key |
| * </UL> |
| * <LI>When there is no conflict, propagates changes made to the |
| * <code>CachedRowSet</code> object back to its underlying data source |
| * <UL> |
| * <LI>Iterates through each row of the <code>CachedRowSet</code> object |
| * to determine whether it has been updated, inserted, or deleted |
| * <LI>If the corresponding row in the data source has not been changed |
| * since the rowset last read its |
| * values, the writer will use the appropriate command to update, |
| * insert, or delete the row |
| * <LI>If any data in the data source does not match the original values |
| * for the <code>CachedRowSet</code> object, the writer will roll |
| * back any changes it has made to the row in the data source. |
| * </UL> |
| * </OL> |
| * |
| * @return <code>true</code> if changes to the rowset were successfully |
| * written to the rowset's underlying data source; |
| * <code>false</code> otherwise |
| */ |
| public boolean writeData(RowSetInternal caller) throws SQLException { |
| boolean conflict = false; |
| boolean showDel = false; |
| PreparedStatement pstmtIns = null; |
| iChangedValsInDbAndCRS = 0; |
| iChangedValsinDbOnly = 0; |
| |
| // We assume caller is a CachedRowSet |
| CachedRowSetImpl crs = (CachedRowSetImpl)caller; |
| // crsResolve = new CachedRowSetImpl(); |
| this.crsResolve = new CachedRowSetImpl();; |
| |
| // The reader is registered with the writer at design time. |
| // This is not required, in general. The reader has logic |
| // to get a JDBC connection, so call it. |
| |
| con = reader.connect(caller); |
| |
| |
| if (con == null) { |
| throw new SQLException(resBundle.handleGetObject("crswriter.connect").toString()); |
| } |
| |
| /* |
| // Fix 6200646. |
| // Don't change the connection or transaction properties. This will fail in a |
| // J2EE container. |
| if (con.getAutoCommit() == true) { |
| con.setAutoCommit(false); |
| } |
| |
| con.setTransactionIsolation(crs.getTransactionIsolation()); |
| */ |
| |
| initSQLStatements(crs); |
| int iColCount; |
| |
| RowSetMetaDataImpl rsmdWrite = (RowSetMetaDataImpl)crs.getMetaData(); |
| RowSetMetaDataImpl rsmdResolv = new RowSetMetaDataImpl(); |
| |
| iColCount = rsmdWrite.getColumnCount(); |
| int sz= crs.size()+1; |
| status = new ArrayList(sz); |
| |
| status.add(0,null); |
| rsmdResolv.setColumnCount(iColCount); |
| |
| for(int i =1; i <= iColCount; i++) { |
| rsmdResolv.setColumnType(i, rsmdWrite.getColumnType(i)); |
| rsmdResolv.setColumnName(i, rsmdWrite.getColumnName(i)); |
| rsmdResolv.setNullable(i, ResultSetMetaData.columnNullableUnknown); |
| } |
| this.crsResolve.setMetaData(rsmdResolv); |
| |
| // moved outside the insert inner loop |
| //pstmtIns = con.prepareStatement(insertCmd); |
| |
| if (callerColumnCount < 1) { |
| // No data, so return success. |
| if (reader.getCloseConnection() == true) |
| con.close(); |
| return true; |
| } |
| // We need to see rows marked for deletion. |
| showDel = crs.getShowDeleted(); |
| crs.setShowDeleted(true); |
| |
| // Look at all the rows. |
| crs.beforeFirst(); |
| |
| int rows =1; |
| while (crs.next()) { |
| if (crs.rowDeleted()) { |
| // The row has been deleted. |
| if (conflict = (deleteOriginalRow(crs, this.crsResolve)) == true) { |
| status.add(rows, new Integer(SyncResolver.DELETE_ROW_CONFLICT)); |
| } else { |
| // delete happened without any occurrence of conflicts |
| // so update status accordingly |
| status.add(rows, new Integer(SyncResolver.NO_ROW_CONFLICT)); |
| } |
| |
| } else if (crs.rowInserted()) { |
| // The row has been inserted. |
| |
| pstmtIns = con.prepareStatement(insertCmd); |
| if ( (conflict = insertNewRow(crs, pstmtIns, this.crsResolve)) == true) { |
| status.add(rows, new Integer(SyncResolver.INSERT_ROW_CONFLICT)); |
| } else { |
| // insert happened without any occurrence of conflicts |
| // so update status accordingly |
| status.add(rows, new Integer(SyncResolver.NO_ROW_CONFLICT)); |
| } |
| } else if (crs.rowUpdated()) { |
| // The row has been updated. |
| if ( conflict = (updateOriginalRow(crs)) == true) { |
| status.add(rows, new Integer(SyncResolver.UPDATE_ROW_CONFLICT)); |
| } else { |
| // update happened without any occurrence of conflicts |
| // so update status accordingly |
| status.add(rows, new Integer(SyncResolver.NO_ROW_CONFLICT)); |
| } |
| |
| } else { |
| /** The row is neither of inserted, updated or deleted. |
| * So set nulls in the this.crsResolve for this row, |
| * as nothing is to be done for such rows. |
| * Also note that if such a row has been changed in database |
| * and we have not changed(inserted, updated or deleted) |
| * that is fine. |
| **/ |
| int icolCount = crs.getMetaData().getColumnCount(); |
| status.add(rows, new Integer(SyncResolver.NO_ROW_CONFLICT)); |
| |
| this.crsResolve.moveToInsertRow(); |
| for(int cols=0;cols<iColCount;cols++) { |
| this.crsResolve.updateNull(cols+1); |
| } //end for |
| |
| this.crsResolve.insertRow(); |
| this.crsResolve.moveToCurrentRow(); |
| |
| } //end if |
| rows++; |
| } //end while |
| |
| // close the insert statement |
| if(pstmtIns!=null) |
| pstmtIns.close(); |
| // reset |
| crs.setShowDeleted(showDel); |
| |
| boolean boolConf = false; |
| for (int j=1;j<status.size();j++){ |
| // ignore status for index = 0 which is set to null |
| if(! ((status.get(j)).equals(new Integer(SyncResolver.NO_ROW_CONFLICT)))) { |
| // there is at least one conflict which needs to be resolved |
| boolConf = true; |
| break; |
| } |
| } |
| |
| crs.beforeFirst(); |
| this.crsResolve.beforeFirst(); |
| |
| if(boolConf) { |
| SyncProviderException spe = new SyncProviderException(status.size() - 1+resBundle.handleGetObject("crswriter.conflictsno").toString()); |
| //SyncResolver syncRes = spe.getSyncResolver(); |
| |
| SyncResolverImpl syncResImpl = (SyncResolverImpl) spe.getSyncResolver(); |
| |
| syncResImpl.setCachedRowSet(crs); |
| syncResImpl.setCachedRowSetResolver(this.crsResolve); |
| |
| syncResImpl.setStatus(status); |
| syncResImpl.setCachedRowSetWriter(this); |
| |
| throw spe; |
| } else { |
| return true; |
| } |
| /* |
| if (conflict == true) { |
| con.rollback(); |
| return false; |
| } else { |
| con.commit(); |
| if (reader.getCloseConnection() == true) { |
| con.close(); |
| } |
| return true; |
| } |
| */ |
| |
| } //end writeData |
| |
| /** |
| * Updates the given <code>CachedRowSet</code> object's underlying data |
| * source so that updates to the rowset are reflected in the original |
| * data source, and returns <code>false</code> if the update was successful. |
| * A return value of <code>true</code> indicates that there is a conflict, |
| * meaning that a value updated in the rowset has already been changed by |
| * someone else in the underlying data source. A conflict can also exist |
| * if, for example, more than one row in the data source would be affected |
| * by the update or if no rows would be affected. In any case, if there is |
| * a conflict, this method does not update the underlying data source. |
| * <P> |
| * This method is called internally by the method <code>writeData</code> |
| * if a row in the <code>CachedRowSet</code> object for which this |
| * <code>CachedRowSetWriter</code> object is the writer has been updated. |
| * |
| * @return <code>false</code> if the update to the underlying data source is |
| * successful; <code>true</code> otherwise |
| * @throws SQLException if a database access error occurs |
| */ |
| private boolean updateOriginalRow(CachedRowSet crs) |
| throws SQLException { |
| PreparedStatement pstmt; |
| int i = 0; |
| int idx = 0; |
| |
| // Select the row from the database. |
| ResultSet origVals = crs.getOriginalRow(); |
| origVals.next(); |
| |
| try { |
| updateWhere = buildWhereClause(updateWhere, origVals); |
| |
| |
| /** |
| * The following block of code is for checking a particular type of |
| * query where in there is a where clause. Without this block, if a |
| * SQL statement is built the "where" clause will appear twice hence |
| * the DB errors out and a SQLException is thrown. This code also |
| * considers that the where clause is in the right place as the |
| * CachedRowSet object would already have been populated with this |
| * query before coming to this point. |
| **/ |
| |
| |
| String tempselectCmd = selectCmd.toLowerCase(); |
| |
| int idxWhere = tempselectCmd.indexOf("where"); |
| |
| if(idxWhere != -1) |
| { |
| String tempSelect = selectCmd.substring(0,idxWhere); |
| selectCmd = tempSelect; |
| } |
| |
| pstmt = con.prepareStatement(selectCmd + updateWhere, |
| ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY); |
| |
| for (i = 0; i < keyCols.length; i++) { |
| if (params[i] != null) { |
| pstmt.setObject(++idx, params[i]); |
| } else { |
| continue; |
| } |
| } |
| |
| try { |
| pstmt.setMaxRows(crs.getMaxRows()); |
| pstmt.setMaxFieldSize(crs.getMaxFieldSize()); |
| pstmt.setEscapeProcessing(crs.getEscapeProcessing()); |
| pstmt.setQueryTimeout(crs.getQueryTimeout()); |
| } catch (Exception ex) { |
| // Older driver don't support these operations. |
| } |
| |
| ResultSet rs = null; |
| rs = pstmt.executeQuery(); |
| if (rs.next() == true) { |
| |
| if (rs.next()) { |
| /** More than one row conflict. |
| * If rs has only one row we are able to |
| * uniquely identify the row where update |
| * have to happen else if more than one |
| * row implies we cannot uniquely identify the row |
| * where we have to do updates. |
| * crs.setKeyColumns needs to be set to |
| * come out of this situation. |
| */ |
| |
| return true; |
| } |
| |
| // don't close the rs |
| // we require the record in rs to be used. |
| // rs.close(); |
| // pstmt.close(); |
| rs.first(); |
| |
| // how many fields need to be updated |
| int colsNotChanged = 0; |
| Vector cols = new Vector(); |
| String updateExec = new String(updateCmd); |
| Object orig; |
| Object curr; |
| Object rsval; |
| boolean boolNull = true; |
| Object objVal = null; |
| |
| // There's only one row and the cursor |
| // needs to be on that row. |
| |
| boolean first = true; |
| boolean flag = true; |
| |
| this.crsResolve.moveToInsertRow(); |
| |
| for (i = 1; i <= callerColumnCount; i++) { |
| orig = origVals.getObject(i); |
| curr = crs.getObject(i); |
| rsval = rs.getObject(i); |
| |
| // reset boolNull if it had been set |
| boolNull = true; |
| |
| /** This addtional checking has been added when the current value |
| * in the DB is null, but the DB had a different value when the |
| * data was actaully fetched into the CachedRowSet. |
| **/ |
| |
| if(rsval == null && orig != null) { |
| // value in db has changed |
| // don't proceed with synchronization |
| // get the value in db and pass it to the resolver. |
| |
| iChangedValsinDbOnly++; |
| // Set the boolNull to false, |
| // in order to set the actual value; |
| boolNull = false; |
| objVal = rsval; |
| } |
| |
| /** Adding the checking for rsval to be "not" null or else |
| * it would through a NullPointerException when the values |
| * are compared. |
| **/ |
| |
| else if(rsval != null && (!rsval.equals(orig))) |
| { |
| // value in db has changed |
| // don't proceed with synchronization |
| // get the value in db and pass it to the resolver. |
| |
| iChangedValsinDbOnly++; |
| // Set the boolNull to false, |
| // in order to set the actual value; |
| boolNull = false; |
| objVal = rsval; |
| } else if ( (orig == null || curr == null) ) { |
| |
| /** Adding the additonal condition of checking for "flag" |
| * boolean variable, which would otherwise result in |
| * building a invalid query, as the comma would not be |
| * added to the query string. |
| **/ |
| |
| if (first == false || flag == false) { |
| updateExec += ", "; |
| } |
| updateExec += crs.getMetaData().getColumnName(i); |
| cols.add(new Integer(i)); |
| updateExec += " = ? "; |
| first = false; |
| |
| /** Adding the extra condition for orig to be "not" null as the |
| * condition for orig to be null is take prior to this, if this |
| * is not added it will result in a NullPointerException when |
| * the values are compared. |
| **/ |
| |
| } else if (orig.equals(curr)) { |
| colsNotChanged++; |
| //nothing to update in this case since values are equal |
| |
| /** Adding the extra condition for orig to be "not" null as the |
| * condition for orig to be null is take prior to this, if this |
| * is not added it will result in a NullPointerException when |
| * the values are compared. |
| **/ |
| |
| } else if(orig.equals(curr) == false) { |
| // When values from db and values in CachedRowSet are not equal, |
| // if db value is same as before updation for each col in |
| // the row before fetching into CachedRowSet, |
| // only then we go ahead with updation, else we |
| // throw SyncProviderException. |
| |
| // if value has changed in db after fetching from db |
| // for some cols of the row and at the same time, some other cols |
| // have changed in CachedRowSet, no synchronization happens |
| |
| // Synchronization happens only when data when fetching is |
| // same or at most has changed in cachedrowset |
| |
| // check orig value with what is there in crs for a column |
| // before updation in crs. |
| |
| if(crs.columnUpdated(i)) { |
| if(rsval.equals(orig)) { |
| // At this point we are sure that |
| // the value updated in crs was from |
| // what is in db now and has not changed |
| if (flag == false || first == false) { |
| updateExec += ", "; |
| } |
| updateExec += crs.getMetaData().getColumnName(i); |
| cols.add(new Integer(i)); |
| updateExec += " = ? "; |
| flag = false; |
| } else { |
| // Here the value has changed in the db after |
| // data was fetched |
| // Plus store this row from CachedRowSet and keep it |
| // in a new CachedRowSet |
| boolNull= false; |
| objVal = rsval; |
| iChangedValsInDbAndCRS++; |
| } |
| } |
| } |
| |
| if(!boolNull) { |
| this.crsResolve.updateObject(i,objVal); |
| } else { |
| this.crsResolve.updateNull(i); |
| } |
| } //end for |
| |
| this.crsResolve.insertRow(); |
| this.crsResolve.moveToCurrentRow(); |
| |
| /** |
| * if nothing has changed return now - this can happen |
| * if column is updated to the same value. |
| * if colsNotChanged == callerColumnCount implies we are updating |
| * the database with ALL COLUMNS HAVING SAME VALUES, |
| * so skip going to database, else do as usual. |
| **/ |
| if ( (first == false && cols.size() == 0) || |
| colsNotChanged == callerColumnCount ) { |
| return false; |
| } |
| |
| if(iChangedValsInDbAndCRS != 0 || iChangedValsinDbOnly != 0) { |
| return true; |
| } |
| |
| |
| updateExec += updateWhere; |
| |
| pstmt = con.prepareStatement(updateExec); |
| |
| // Comments needed here |
| for (i = 0; i < cols.size(); i++) { |
| Object obj = crs.getObject(((Integer)cols.get(i)).intValue()); |
| if (obj != null) |
| pstmt.setObject(i + 1, obj); |
| else |
| pstmt.setNull(i + 1,crs.getMetaData().getColumnType(i + 1)); |
| } |
| idx = i; |
| |
| // Comments needed here |
| for (i = 0; i < keyCols.length; i++) { |
| if (params[i] != null) { |
| pstmt.setObject(++idx, params[i]); |
| } else { |
| continue; |
| } |
| } |
| |
| i = pstmt.executeUpdate(); |
| |
| /** |
| * i should be equal to 1(row count), because we update |
| * one row(returned as row count) at a time, if all goes well. |
| * if 1 != 1, this implies we have not been able to |
| * do updations properly i.e there is a conflict in database |
| * versus what is in CachedRowSet for this particular row. |
| **/ |
| |
| return false; |
| |
| } else { |
| /** |
| * Cursor will be here, if the ResultSet may not return even a single row |
| * i.e. we can't find the row where to update because it has been deleted |
| * etc. from the db. |
| * Present the whole row as null to user, to force null to be sync'ed |
| * and hence nothing to be synced. |
| * |
| * NOTE: |
| * ------ |
| * In the database if a column that is mapped to java.sql.Types.REAL stores |
| * a Double value and is compared with value got from ResultSet.getFloat() |
| * no row is retrieved and will throw a SyncProviderException. For details |
| * see bug Id 5053830 |
| **/ |
| return true; |
| } |
| } catch (SQLException ex) { |
| ex.printStackTrace(); |
| // if executeUpdate fails it will come here, |
| // update crsResolve with null rows |
| this.crsResolve.moveToInsertRow(); |
| |
| for(i = 1; i <= callerColumnCount; i++) { |
| this.crsResolve.updateNull(i); |
| } |
| |
| this.crsResolve.insertRow(); |
| this.crsResolve.moveToCurrentRow(); |
| |
| return true; |
| } |
| } |
| |
| /** |
| * Inserts a row that has been inserted into the given |
| * <code>CachedRowSet</code> object into the data source from which |
| * the rowset is derived, returning <code>false</code> if the insertion |
| * was successful. |
| * |
| * @param crs the <code>CachedRowSet</code> object that has had a row inserted |
| * and to whose underlying data source the row will be inserted |
| * @param pstmt the <code>PreparedStatement</code> object that will be used |
| * to execute the insertion |
| * @return <code>false</code> to indicate that the insertion was successful; |
| * <code>true</code> otherwise |
| * @throws SQLException if a database access error occurs |
| */ |
| private boolean insertNewRow(CachedRowSet crs, |
| PreparedStatement pstmt, CachedRowSetImpl crsRes) throws SQLException { |
| int i = 0; |
| int icolCount = crs.getMetaData().getColumnCount(); |
| |
| boolean returnVal = false; |
| PreparedStatement pstmtSel = con.prepareStatement(selectCmd, |
| ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY); |
| ResultSet rs, rs2 = null; |
| DatabaseMetaData dbmd = con.getMetaData(); |
| rs = pstmtSel.executeQuery(); |
| String table = crs.getTableName(); |
| rs2 = dbmd.getPrimaryKeys(null, null, table); |
| String [] primaryKeys = new String[icolCount]; |
| int k = 0; |
| while(rs2.next()) { |
| String pkcolname = rs2.getString("COLUMN_NAME"); |
| primaryKeys[k] = pkcolname; |
| k++; |
| } |
| |
| if(rs.next()) { |
| for(int j=0;j<primaryKeys.length;j++) { |
| if(primaryKeys[j] != null) { |
| if(crs.getObject(primaryKeys[j]) == null){ |
| break; |
| } |
| String crsPK = (crs.getObject(primaryKeys[j])).toString(); |
| String rsPK = (rs.getObject(primaryKeys[j])).toString(); |
| if(crsPK.equals(rsPK)) { |
| returnVal = true; |
| this.crsResolve.moveToInsertRow(); |
| for(i = 1; i <= icolCount; i++) { |
| String colname = (rs.getMetaData()).getColumnName(i); |
| if(colname.equals(primaryKeys[j])) |
| this.crsResolve.updateObject(i,rsPK); |
| else |
| this.crsResolve.updateNull(i); |
| } |
| this.crsResolve.insertRow(); |
| this.crsResolve.moveToCurrentRow(); |
| } |
| } |
| } |
| } |
| if(returnVal) |
| return returnVal; |
| |
| try { |
| for (i = 1; i <= icolCount; i++) { |
| Object obj = crs.getObject(i); |
| if (obj != null) { |
| pstmt.setObject(i, obj); |
| } else { |
| pstmt.setNull(i,crs.getMetaData().getColumnType(i)); |
| } |
| } |
| |
| i = pstmt.executeUpdate(); |
| return false; |
| |
| } catch (SQLException ex) { |
| /** |
| * Cursor will come here if executeUpdate fails. |
| * There can be many reasons why the insertion failed, |
| * one can be violation of primary key. |
| * Hence we cannot exactly identify why the insertion failed |
| * Present the current row as a null row to the user. |
| **/ |
| this.crsResolve.moveToInsertRow(); |
| |
| for(i = 1; i <= icolCount; i++) { |
| this.crsResolve.updateNull(i); |
| } |
| |
| this.crsResolve.insertRow(); |
| this.crsResolve.moveToCurrentRow(); |
| |
| return true; |
| } |
| } |
| |
| /** |
| * Deletes the row in the underlying data source that corresponds to |
| * a row that has been deleted in the given <code> CachedRowSet</code> object |
| * and returns <code>false</code> if the deletion was successful. |
| * <P> |
| * This method is called internally by this writer's <code>writeData</code> |
| * method when a row in the rowset has been deleted. The values in the |
| * deleted row are the same as those that are stored in the original row |
| * of the given <code>CachedRowSet</code> object. If the values in the |
| * original row differ from the row in the underlying data source, the row |
| * in the data source is not deleted, and <code>deleteOriginalRow</code> |
| * returns <code>true</code> to indicate that there was a conflict. |
| * |
| * |
| * @return <code>false</code> if the deletion was successful, which means that |
| * there was no conflict; <code>true</code> otherwise |
| * @throws SQLException if there was a database access error |
| */ |
| private boolean deleteOriginalRow(CachedRowSet crs, CachedRowSetImpl crsRes) throws SQLException { |
| PreparedStatement pstmt; |
| int i; |
| int idx = 0; |
| String strSelect; |
| // Select the row from the database. |
| ResultSet origVals = crs.getOriginalRow(); |
| origVals.next(); |
| |
| deleteWhere = buildWhereClause(deleteWhere, origVals); |
| pstmt = con.prepareStatement(selectCmd + deleteWhere, |
| ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY); |
| |
| for (i = 0; i < keyCols.length; i++) { |
| if (params[i] != null) { |
| pstmt.setObject(++idx, params[i]); |
| } else { |
| continue; |
| } |
| } |
| |
| try { |
| pstmt.setMaxRows(crs.getMaxRows()); |
| pstmt.setMaxFieldSize(crs.getMaxFieldSize()); |
| pstmt.setEscapeProcessing(crs.getEscapeProcessing()); |
| pstmt.setQueryTimeout(crs.getQueryTimeout()); |
| } catch (Exception ex) { |
| /* |
| * Older driver don't support these operations... |
| */ |
| ; |
| } |
| |
| ResultSet rs = pstmt.executeQuery(); |
| |
| if (rs.next() == true) { |
| if (rs.next()) { |
| // more than one row |
| return true; |
| } |
| rs.first(); |
| |
| // Now check all the values in rs to be same in |
| // db also before actually going ahead with deleting |
| boolean boolChanged = false; |
| |
| crsRes.moveToInsertRow(); |
| |
| for (i = 1; i <= crs.getMetaData().getColumnCount(); i++) { |
| |
| Object original = origVals.getObject(i); |
| Object changed = rs.getObject(i); |
| |
| if(original != null && changed != null ) { |
| if(! (original.toString()).equals(changed.toString()) ) { |
| boolChanged = true; |
| crsRes.updateObject(i,origVals.getObject(i)); |
| } |
| } else { |
| crsRes.updateNull(i); |
| } |
| } |
| |
| crsRes.insertRow(); |
| crsRes.moveToCurrentRow(); |
| |
| if(boolChanged) { |
| // do not delete as values in db have changed |
| // deletion will not happen for this row from db |
| // exit now returning true. i.e. conflict |
| return true; |
| } else { |
| // delete the row. |
| // Go ahead with deleting, |
| // don't do anything here |
| } |
| |
| String cmd = deleteCmd + deleteWhere; |
| pstmt = con.prepareStatement(cmd); |
| |
| idx = 0; |
| for (i = 0; i < keyCols.length; i++) { |
| if (params[i] != null) { |
| pstmt.setObject(++idx, params[i]); |
| } else { |
| continue; |
| } |
| } |
| |
| if (pstmt.executeUpdate() != 1) { |
| return true; |
| } |
| pstmt.close(); |
| } else { |
| // didn't find the row |
| return true; |
| } |
| |
| // no conflict |
| return false; |
| } |
| |
| /** |
| * Sets the reader for this writer to the given reader. |
| * |
| * @throws SQLException if a database access error occurs |
| */ |
| public void setReader(CachedRowSetReader reader) throws SQLException { |
| this.reader = reader; |
| } |
| |
| /** |
| * Gets the reader for this writer. |
| * |
| * @throws SQLException if a database access error occurs |
| */ |
| public CachedRowSetReader getReader() throws SQLException { |
| return reader; |
| } |
| |
| /** |
| * Composes a <code>SELECT</code>, <code>UPDATE</code>, <code>INSERT</code>, |
| * and <code>DELETE</code> statement that can be used by this writer to |
| * write data to the data source backing the given <code>CachedRowSet</code> |
| * object. |
| * |
| * @ param caller a <code>CachedRowSet</code> object for which this |
| * <code>CachedRowSetWriter</code> object is the writer |
| * @throws SQLException if a database access error occurs |
| */ |
| private void initSQLStatements(CachedRowSet caller) throws SQLException { |
| |
| int i; |
| |
| callerMd = caller.getMetaData(); |
| callerColumnCount = callerMd.getColumnCount(); |
| if (callerColumnCount < 1) |
| // No data, so return. |
| return; |
| |
| /* |
| * If the RowSet has a Table name we should use it. |
| * This is really a hack to get round the fact that |
| * a lot of the jdbc drivers can't provide the tab. |
| */ |
| String table = caller.getTableName(); |
| if (table == null) { |
| /* |
| * attempt to build a table name using the info |
| * that the driver gave us for the first column |
| * in the source result set. |
| */ |
| table = callerMd.getTableName(1); |
| if (table == null || table.length() == 0) { |
| throw new SQLException(resBundle.handleGetObject("crswriter.tname").toString()); |
| } |
| } |
| String catalog = callerMd.getCatalogName(1); |
| String schema = callerMd.getSchemaName(1); |
| DatabaseMetaData dbmd = con.getMetaData(); |
| |
| /* |
| * Compose a SELECT statement. There are three parts. |
| */ |
| |
| // Project List |
| selectCmd = "SELECT "; |
| for (i=1; i <= callerColumnCount; i++) { |
| selectCmd += callerMd.getColumnName(i); |
| if ( i < callerMd.getColumnCount() ) |
| selectCmd += ", "; |
| else |
| selectCmd += " "; |
| } |
| |
| // FROM clause. |
| selectCmd += "FROM " + buildTableName(dbmd, catalog, schema, table); |
| |
| /* |
| * Compose an UPDATE statement. |
| */ |
| updateCmd = "UPDATE " + buildTableName(dbmd, catalog, schema, table); |
| |
| |
| /** |
| * The following block of code is for checking a particular type of |
| * query where in there is a where clause. Without this block, if a |
| * SQL statement is built the "where" clause will appear twice hence |
| * the DB errors out and a SQLException is thrown. This code also |
| * considers that the where clause is in the right place as the |
| * CachedRowSet object would already have been populated with this |
| * query before coming to this point. |
| **/ |
| |
| String tempupdCmd = updateCmd.toLowerCase(); |
| |
| int idxupWhere = tempupdCmd.indexOf("where"); |
| |
| if(idxupWhere != -1) |
| { |
| updateCmd = updateCmd.substring(0,idxupWhere); |
| } |
| updateCmd += "SET "; |
| |
| /* |
| * Compose an INSERT statement. |
| */ |
| insertCmd = "INSERT INTO " + buildTableName(dbmd, catalog, schema, table); |
| // Column list |
| insertCmd += "("; |
| for (i=1; i <= callerColumnCount; i++) { |
| insertCmd += callerMd.getColumnName(i); |
| if ( i < callerMd.getColumnCount() ) |
| insertCmd += ", "; |
| else |
| insertCmd += ") VALUES ("; |
| } |
| for (i=1; i <= callerColumnCount; i++) { |
| insertCmd += "?"; |
| if (i < callerColumnCount) |
| insertCmd += ", "; |
| else |
| insertCmd += ")"; |
| } |
| |
| /* |
| * Compose a DELETE statement. |
| */ |
| deleteCmd = "DELETE FROM " + buildTableName(dbmd, catalog, schema, table); |
| |
| /* |
| * set the key desriptors that will be |
| * needed to construct where clauses. |
| */ |
| buildKeyDesc(caller); |
| } |
| |
| /** |
| * Returns a fully qualified table name built from the given catalog and |
| * table names. The given metadata object is used to get the proper order |
| * and separator. |
| * |
| * @param dbmd a <code>DatabaseMetaData</code> object that contains metadata |
| * about this writer's <code>CachedRowSet</code> object |
| * @param catalog a <code>String</code> object with the rowset's catalog |
| * name |
| * @param table a <code>String</code> object with the name of the table from |
| * which this writer's rowset was derived |
| * @return a <code>String</code> object with the fully qualified name of the |
| * table from which this writer's rowset was derived |
| * @throws SQLException if a database access error occurs |
| */ |
| private String buildTableName(DatabaseMetaData dbmd, |
| String catalog, String schema, String table) throws SQLException { |
| |
| // trim all the leading and trailing whitespaces, |
| // white spaces can never be catalog, schema or a table name. |
| |
| String cmd = new String(); |
| |
| catalog = catalog.trim(); |
| schema = schema.trim(); |
| table = table.trim(); |
| |
| if (dbmd.isCatalogAtStart() == true) { |
| if (catalog != null && catalog.length() > 0) { |
| cmd += catalog + dbmd.getCatalogSeparator(); |
| } |
| if (schema != null && schema.length() > 0) { |
| cmd += schema + "."; |
| } |
| cmd += table; |
| } else { |
| if (schema != null && schema.length() > 0) { |
| cmd += schema + "."; |
| } |
| cmd += table; |
| if (catalog != null && catalog.length() > 0) { |
| cmd += dbmd.getCatalogSeparator() + catalog; |
| } |
| } |
| cmd += " "; |
| return cmd; |
| } |
| |
| /** |
| * Assigns to the given <code>CachedRowSet</code> object's |
| * <code>params</code> |
| * field an array whose length equals the number of columns needed |
| * to uniquely identify a row in the rowset. The array is given |
| * values by the method <code>buildWhereClause</code>. |
| * <P> |
| * If the <code>CachedRowSet</code> object's <code>keyCols</code> |
| * field has length <code>0</code> or is <code>null</code>, the array |
| * is set with the column number of every column in the rowset. |
| * Otherwise, the array in the field <code>keyCols</code> is set with only |
| * the column numbers of the columns that are required to form a unique |
| * identifier for a row. |
| * |
| * @param crs the <code>CachedRowSet</code> object for which this |
| * <code>CachedRowSetWriter</code> object is the writer |
| * |
| * @throws SQLException if a database access error occurs |
| */ |
| private void buildKeyDesc(CachedRowSet crs) throws SQLException { |
| |
| keyCols = crs.getKeyColumns(); |
| if (keyCols == null || keyCols.length == 0) { |
| keyCols = new int[callerColumnCount]; |
| for (int i = 0; i < keyCols.length; ) { |
| keyCols[i] = ++i; |
| } |
| } |
| params = new Object[keyCols.length]; |
| } |
| |
| /** |
| * Constructs an SQL <code>WHERE</code> clause using the given |
| * string as a starting point. The resulting clause will contain |
| * a column name and " = ?" for each key column, that is, each column |
| * that is needed to form a unique identifier for a row in the rowset. |
| * This <code>WHERE</code> clause can be added to |
| * a <code>PreparedStatement</code> object that updates, inserts, or |
| * deletes a row. |
| * <P> |
| * This method uses the given result set to access values in the |
| * <code>CachedRowSet</code> object that called this writer. These |
| * values are used to build the array of parameters that will serve as |
| * replacements for the "?" parameter placeholders in the |
| * <code>PreparedStatement</code> object that is sent to the |
| * <code>CachedRowSet</code> object's underlying data source. |
| * |
| * @param whereClause a <code>String</code> object that is an empty |
| * string ("") |
| * @param rs a <code>ResultSet</code> object that can be used |
| * to access the <code>CachedRowSet</code> object's data |
| * @return a <code>WHERE</code> clause of the form "<code>WHERE</code> |
| * columnName = ? AND columnName = ? AND columnName = ? ..." |
| * @throws SQLException if a database access error occurs |
| */ |
| private String buildWhereClause(String whereClause, |
| ResultSet rs) throws SQLException { |
| whereClause = "WHERE "; |
| |
| for (int i = 0; i < keyCols.length; i++) { |
| if (i > 0) { |
| whereClause += "AND "; |
| } |
| whereClause += callerMd.getColumnName(keyCols[i]); |
| params[i] = rs.getObject(keyCols[i]); |
| if (rs.wasNull() == true) { |
| whereClause += " IS NULL "; |
| } else { |
| whereClause += " = ? "; |
| } |
| } |
| return whereClause; |
| } |
| |
| void updateResolvedConflictToDB(CachedRowSet crs, Connection con) throws SQLException { |
| //String updateExe = ; |
| PreparedStatement pStmt ; |
| String strWhere = "WHERE " ; |
| String strExec =" "; |
| String strUpdate = "UPDATE "; |
| int icolCount = crs.getMetaData().getColumnCount(); |
| int keyColumns[] = crs.getKeyColumns(); |
| Object param[]; |
| String strSet=""; |
| |
| strWhere = buildWhereClause(strWhere, crs); |
| |
| if (keyColumns == null || keyColumns.length == 0) { |
| keyColumns = new int[icolCount]; |
| for (int i = 0; i < keyColumns.length; ) { |
| keyColumns[i] = ++i; |
| } |
| } |
| param = new Object[keyColumns.length]; |
| |
| strUpdate = "UPDATE " + buildTableName(con.getMetaData(), |
| crs.getMetaData().getCatalogName(1), |
| crs.getMetaData().getSchemaName(1), |
| crs.getTableName()); |
| |
| // changed or updated values will become part of |
| // set clause here |
| strUpdate += "SET "; |
| |
| boolean first = true; |
| |
| for (int i=1; i<=icolCount;i++) { |
| if (crs.columnUpdated(i)) { |
| if (first == false) { |
| strSet += ", "; |
| } |
| strSet += crs.getMetaData().getColumnName(i); |
| strSet += " = ? "; |
| first = false; |
| } //end if |
| } //end for |
| |
| // keycols will become part of where clause |
| strUpdate += strSet; |
| strWhere = "WHERE "; |
| |
| for (int i = 0; i < keyColumns.length; i++) { |
| if (i > 0) { |
| strWhere += "AND "; |
| } |
| strWhere += crs.getMetaData().getColumnName(keyColumns[i]); |
| param[i] = crs.getObject(keyColumns[i]); |
| if (crs.wasNull() == true) { |
| strWhere += " IS NULL "; |
| } else { |
| strWhere += " = ? "; |
| } |
| } |
| strUpdate += strWhere; |
| |
| pStmt = con.prepareStatement(strUpdate); |
| |
| int idx =0; |
| for (int i = 0; i < icolCount; i++) { |
| if(crs.columnUpdated(i+1)) { |
| Object obj = crs.getObject(i+1); |
| if (obj != null) { |
| pStmt.setObject(++idx, obj); |
| } else { |
| pStmt.setNull(i + 1,crs.getMetaData().getColumnType(i + 1)); |
| } //end if ..else |
| } //end if crs.column... |
| } //end for |
| |
| // Set the key cols for after WHERE =? clause |
| for (int i = 0; i < keyColumns.length; i++) { |
| if (param[i] != null) { |
| pStmt.setObject(++idx, param[i]); |
| } |
| } |
| |
| int id = pStmt.executeUpdate(); |
| } |
| |
| |
| /** |
| * |
| */ |
| public void commit() throws SQLException { |
| con.commit(); |
| if (reader.getCloseConnection() == true) { |
| con.close(); |
| } |
| } |
| |
| public void commit(CachedRowSetImpl crs, boolean updateRowset) throws SQLException { |
| con.commit(); |
| if(updateRowset) { |
| if(crs.getCommand() != null) |
| crs.execute(con); |
| } |
| |
| if (reader.getCloseConnection() == true) { |
| con.close(); |
| } |
| } |
| |
| /** |
| * |
| */ |
| public void rollback() throws SQLException { |
| con.rollback(); |
| if (reader.getCloseConnection() == true) { |
| con.close(); |
| } |
| } |
| |
| /** |
| * |
| */ |
| public void rollback(Savepoint s) throws SQLException { |
| con.rollback(s); |
| if (reader.getCloseConnection() == true) { |
| con.close(); |
| } |
| } |
| |
| } |
