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	/*
	* Copyright (c) 2003, 2011, 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 javax.naming.*;
	import java.io.*;
	import java.lang.reflect.*;

	import com.sun.rowset.*;
	import javax.sql.rowset.*;
	import javax.sql.rowset.spi.*;

	/**
	* The facility called by the <code>RIOptimisticProvider</code> object
	* internally to read data into it. The calling <code>RowSet</code> object
	* must have implemented the <code>RowSetInternal</code> interface
	* and have the standard <code>CachedRowSetReader</code> object set as its
	* reader.
	* <P>
	* This implementation always reads all rows of the data source,
	* and it assumes that the <code>command</code> property for the caller
	* is set with a query that is appropriate for execution by a
	* <code>PreparedStatement</code> object.
	* <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
	* reader by invoking the <code>SyncProvider.getRowSetReader()</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 CachedRowSetReader implements RowSetReader, Serializable {

	/**
	* The field that keeps track of whether the writer associated with
	* this <code>CachedRowSetReader</code> object's rowset has been called since
	* the rowset was populated.
	* <P>
	* When this <code>CachedRowSetReader</code> object reads data into
	* its rowset, it sets the field <code>writerCalls</code> to 0.
	* When the writer associated with the rowset is called to write
	* data back to the underlying data source, its <code>writeData</code>
	* method calls the method <code>CachedRowSetReader.reset</code>,
	* which increments <code>writerCalls</code> and returns <code>true</code>
	* if <code>writerCalls</code> is 1. Thus, <code>writerCalls</code> equals
	* 1 after the first call to <code>writeData</code> that occurs
	* after the rowset has had data read into it.
	*
	* @serial
	*/
	private int writerCalls = 0;

	private boolean userCon = false;

	private int startPosition;

	private JdbcRowSetResourceBundle resBundle;

	public CachedRowSetReader() {
	try {
	resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();
	} catch(IOException ioe) {
	throw new RuntimeException(ioe);
	}
	}


	/**
	* Reads data from a data source and populates the given
	* <code>RowSet</code> object with that data.
	* This method is called by the rowset internally when
	* the application invokes the method <code>execute</code>
	* to read a new set of rows.
	* <P>
	* After clearing the rowset of its contents, if any, and setting
	* the number of writer calls to <code>0</code>, this reader calls
	* its <code>connect</code> method to make
	* a connection to the rowset's data source. Depending on which
	* of the rowset's properties have been set, the <code>connect</code>
	* method will use a <code>DataSource</code> object or the
	* <code>DriverManager</code> facility to make a connection to the
	* data source.
	* <P>
	* Once the connection to the data source is made, this reader
	* executes the query in the calling <code>CachedRowSet</code> object's
	* <code>command</code> property. Then it calls the rowset's
	* <code>populate</code> method, which reads data from the
	* <code>ResultSet</code> object produced by executing the rowset's
	* command. The rowset is then populated with this data.
	* <P>
	* This method's final act is to close the connection it made, thus
	* leaving the rowset disconnected from its data source.
	*
	* @param caller a <code>RowSet</code> object that has implemented
	* the <code>RowSetInternal</code> interface and had
	* this <code>CachedRowSetReader</code> object set as
	* its reader
	* @throws SQLException if there is a database access error, there is a
	* problem making the connection, or the command property has not
	* been set
	*/
	public void readData(RowSetInternal caller) throws SQLException
	{
	Connection con = null;
	try {
	CachedRowSet crs = (CachedRowSet)caller;

	// Get rid of the current contents of the rowset.

	/**
	* Checking added to verify whether page size has been set or not.
	* If set then do not close the object as certain parameters need
	* to be maintained.
	*/

	if(crs.getPageSize() == 0 && crs.size() >0 ) {
	// When page size is not set,
	// crs.size() will show the total no of rows.
	crs.close();
	}

	writerCalls = 0;

	// Get a connection. This reader assumes that the necessary
	// properties have been set on the caller to let it supply a
	// connection.
	userCon = false;

	con = this.connect(caller);

	// Check our assumptions.
	if (con == null \|\| crs.getCommand() == null)
	throw new SQLException(resBundle.handleGetObject("crsreader.connecterr").toString());

	try {
	con.setTransactionIsolation(crs.getTransactionIsolation());
	} catch (Exception ex) {
	;
	}
	// Use JDBC to read the data.
	PreparedStatement pstmt = con.prepareStatement(crs.getCommand());
	// Pass any input parameters to JDBC.

	decodeParams(caller.getParams(), pstmt);
	try {
	pstmt.setMaxRows(crs.getMaxRows());
	pstmt.setMaxFieldSize(crs.getMaxFieldSize());
	pstmt.setEscapeProcessing(crs.getEscapeProcessing());
	pstmt.setQueryTimeout(crs.getQueryTimeout());
	} catch (Exception ex) {
	/*
	* drivers may not support the above - esp. older
	* drivers being used by the bridge..
	*/
	throw new SQLException(ex.getMessage());
	}

	if(crs.getCommand().toLowerCase().indexOf("select") != -1) {
	// can be (crs.getCommand()).indexOf("select")) == 0
	// because we will be getting resultset when
	// it may be the case that some false select query with
	// select coming in between instead of first.

	// if ((crs.getCommand()).indexOf("?")) does not return -1
	// implies a Prepared Statement like query exists.

	ResultSet rs = pstmt.executeQuery();
	if(crs.getPageSize() == 0){
	crs.populate(rs);
	}
	else {
	/**
	* If page size has been set then create a ResultSet object that is scrollable using a
	* PreparedStatement handle.Also call the populate(ResultSet,int) function to populate
	* a page of data as specified by the page size.
	*/
	pstmt = con.prepareStatement(crs.getCommand(),ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
	decodeParams(caller.getParams(), pstmt);
	try {
	pstmt.setMaxRows(crs.getMaxRows());
	pstmt.setMaxFieldSize(crs.getMaxFieldSize());
	pstmt.setEscapeProcessing(crs.getEscapeProcessing());
	pstmt.setQueryTimeout(crs.getQueryTimeout());
	} catch (Exception ex) {
	/*
	* drivers may not support the above - esp. older
	* drivers being used by the bridge..
	*/
	throw new SQLException(ex.getMessage());
	}
	rs = pstmt.executeQuery();
	crs.populate(rs,startPosition);
	}
	rs.close();
	} else {
	pstmt.executeUpdate();
	}

	// Get the data.
	pstmt.close();
	try {
	con.commit();
	} catch (SQLException ex) {
	;
	}
	// only close connections we created...
	if (getCloseConnection() == true)
	con.close();
	}
	catch (SQLException ex) {
	// Throw an exception if reading fails for any reason.
	throw ex;
	} finally {
	try {
	// only close connections we created...
	if (con != null && getCloseConnection() == true) {
	try {
	if (!con.getAutoCommit()) {
	con.rollback();
	}
	} catch (Exception dummy) {
	/*
	* not an error condition, we're closing anyway, but
	* we'd like to clean up any locks if we can since
	* it is not clear the connection pool will clean
	* these connections in a timely manner
	*/
	}
	con.close();
	con = null;
	}
	} catch (SQLException e) {
	// will get exception if something already went wrong, but don't
	// override that exception with this one
	}
	}
	}

	/**
	* Checks to see if the writer associated with this reader needs
	* to reset its state. The writer will need to initialize its state
	* if new contents have been read since the writer was last called.
	* This method is called by the writer that was registered with
	* this reader when components were being wired together.
	*
	* @return <code>true</code> if writer associated with this reader needs
	* to reset the values of its fields; <code>false</code> otherwise
	* @throws SQLException if an access error occurs
	*/
	public boolean reset() throws SQLException {
	writerCalls++;
	return writerCalls == 1;
	}

	/**
	* Establishes a connection with the data source for the given
	* <code>RowSet</code> object. If the rowset's <code>dataSourceName</code>
	* property has been set, this method uses the JNDI API to retrieve the
	* <code>DataSource</code> object that it can use to make the connection.
	* If the url, username, and password properties have been set, this
	* method uses the <code>DriverManager.getConnection</code> method to
	* make the connection.
	* <P>
	* This method is used internally by the reader and writer associated with
	* the calling <code>RowSet</code> object; an application never calls it
	* directly.
	*
	* @param caller a <code>RowSet</code> object that has implemented
	* the <code>RowSetInternal</code> interface and had
	* this <code>CachedRowSetReader</code> object set as
	* its reader
	* @return a <code>Connection</code> object that represents a connection
	* to the caller's data source
	* @throws SQLException if an access error occurs
	*/
	public Connection connect(RowSetInternal caller) throws SQLException {

	// Get a JDBC connection.
	if (caller.getConnection() != null) {
	// A connection was passed to execute(), so use it.
	// As we are using a connection the user gave us we
	// won't close it.
	userCon = true;
	return caller.getConnection();
	}
	else if (((RowSet)caller).getDataSourceName() != null) {
	// Connect using JNDI.
	try {
	Context ctx = new InitialContext();
	DataSource ds = (DataSource)ctx.lookup
	(((RowSet)caller).getDataSourceName());

	// Check for username, password,
	// if it exists try getting a Connection handle through them
	// else try without these
	// else throw SQLException

	if(((RowSet)caller).getUsername() != null) {
	return ds.getConnection(((RowSet)caller).getUsername(),
	((RowSet)caller).getPassword());
	} else {
	return ds.getConnection();
	}
	}
	catch (javax.naming.NamingException ex) {
	SQLException sqlEx = new SQLException(resBundle.handleGetObject("crsreader.connect").toString());
	sqlEx.initCause(ex);
	throw sqlEx;
	}
	} else if (((RowSet)caller).getUrl() != null) {
	// Connect using the driver manager.
	return DriverManager.getConnection(((RowSet)caller).getUrl(),
	((RowSet)caller).getUsername(),
	((RowSet)caller).getPassword());
	}
	else {
	return null;
	}
	}

	/**
	* Sets the parameter placeholders
	* in the rowset's command (the given <code>PreparedStatement</code>
	* object) with the parameters in the given array.
	* This method, called internally by the method
	* <code>CachedRowSetReader.readData</code>, reads each parameter, and
	* based on its type, determines the correct
	* <code>PreparedStatement.setXXX</code> method to use for setting
	* that parameter.
	*
	* @param params an array of parameters to be used with the given
	* <code>PreparedStatement</code> object
	* @param pstmt the <code>PreparedStatement</code> object that is the
	* command for the calling rowset and into which
	* the given parameters are to be set
	* @throws SQLException if an access error occurs
	*/
	@SuppressWarnings("deprecation")
	private void decodeParams(Object[] params,
	PreparedStatement pstmt) throws SQLException {
	// There is a corresponding decodeParams in JdbcRowSetImpl
	// which does the same as this method. This is a design flaw.
	// Update the JdbcRowSetImpl.decodeParams when you update
	// this method.

	// Adding the same comments to JdbcRowSetImpl.decodeParams.

	int arraySize;
	Object[] param = null;

	for (int i=0; i < params.length; i++) {
	if (params[i] instanceof Object[]) {
	param = (Object[])params[i];

	if (param.length == 2) {
	if (param[0] == null) {
	pstmt.setNull(i + 1, ((Integer)param[1]).intValue());
	continue;
	}

	if (param[0] instanceof java.sql.Date \|\|
	param[0] instanceof java.sql.Time \|\|
	param[0] instanceof java.sql.Timestamp) {
	System.err.println(resBundle.handleGetObject("crsreader.datedetected").toString());
	if (param[1] instanceof java.util.Calendar) {
	System.err.println(resBundle.handleGetObject("crsreader.caldetected").toString());
	pstmt.setDate(i + 1, (java.sql.Date)param[0],
	(java.util.Calendar)param[1]);
	continue;
	}
	else {
	throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString());
	}
	}

	if (param[0] instanceof Reader) {
	pstmt.setCharacterStream(i + 1, (Reader)param[0],
	((Integer)param[1]).intValue());
	continue;
	}

	/*
	* What's left should be setObject(int, Object, scale)
	*/
	if (param[1] instanceof Integer) {
	pstmt.setObject(i + 1, param[0], ((Integer)param[1]).intValue());
	continue;
	}

	} else if (param.length == 3) {

	if (param[0] == null) {
	pstmt.setNull(i + 1, ((Integer)param[1]).intValue(),
	(String)param[2]);
	continue;
	}

	if (param[0] instanceof java.io.InputStream) {
	switch (((Integer)param[2]).intValue()) {
	case CachedRowSetImpl.UNICODE_STREAM_PARAM:
	pstmt.setUnicodeStream(i + 1,
	(java.io.InputStream)param[0],
	((Integer)param[1]).intValue());
	break;
	case CachedRowSetImpl.BINARY_STREAM_PARAM:
	pstmt.setBinaryStream(i + 1,
	(java.io.InputStream)param[0],
	((Integer)param[1]).intValue());
	break;
	case CachedRowSetImpl.ASCII_STREAM_PARAM:
	pstmt.setAsciiStream(i + 1,
	(java.io.InputStream)param[0],
	((Integer)param[1]).intValue());
	break;
	default:
	throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString());
	}
	}

	/*
	* no point at looking at the first element now;
	* what's left must be the setObject() cases.
	*/
	if (param[1] instanceof Integer && param[2] instanceof Integer) {
	pstmt.setObject(i + 1, param[0], ((Integer)param[1]).intValue(),
	((Integer)param[2]).intValue());
	continue;
	}

	throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString());

	} else {
	// common case - this catches all SQL92 types
	pstmt.setObject(i + 1, params[i]);
	continue;
	}
	} else {
	// Try to get all the params to be set here
	pstmt.setObject(i + 1, params[i]);

	}
	}
	}

	/**
	* Assists in determining whether the current connection was created by this
	* CachedRowSet to ensure incorrect connections are not prematurely terminated.
	*
	* @return a boolean giving the status of whether the connection has been closed.
	*/
	protected boolean getCloseConnection() {
	if (userCon == true)
	return false;

	return true;
	}

	/**
	* This sets the start position in the ResultSet from where to begin. This is
	* called by the Reader in the CachedRowSetImpl to set the position on the page
	* to begin populating from.
	* @param pos integer indicating the position in the <code>ResultSet</code> to begin
	* populating from.
	*/
	public void setStartPosition(int pos){
	startPosition = pos;
	}

	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
	// Default state initialization happens here
	ois.defaultReadObject();
	// Initialization of Res Bundle happens here .
	try {
	resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();
	} catch(IOException ioe) {
	throw new RuntimeException(ioe);
	}

	}

	static final long serialVersionUID =5049738185801363801L;
	}

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