abstractjdbc2resultset.java

来自「PostgreSQL7.4.6 for Linux」· Java 代码 · 共 1,625 行 · 第 1/3 页

/*-------------------------------------------------------------------------
 *
 * AbstractJdbc2ResultSet.java
 *     This class defines methods of the jdbc2 specification.  This class 
 *     extends org.postgresql.jdbc1.AbstractJdbc1ResultSet which provides the 
 *     jdbc1 methods.  The real Statement class (for jdbc2) is 
 *     org.postgresql.jdbc2.Jdbc2ResultSet
 *
 * Copyright (c) 2003, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/jdbc2/Attic/AbstractJdbc2ResultSet.java,v 1.25.2.9 2004/09/13 07:14:26 jurka Exp $
 *
 *-------------------------------------------------------------------------
 */
package org.postgresql.jdbc2;

import java.io.CharArrayReader;
import java.io.InputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.sql.*;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.util.Vector;
import org.postgresql.Driver;
import org.postgresql.core.BaseStatement;
import org.postgresql.core.Field;
import org.postgresql.core.Encoding;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;


public abstract class AbstractJdbc2ResultSet extends org.postgresql.jdbc1.AbstractJdbc1ResultSet
{

	//needed for updateable result set support
	protected boolean updateable = false;
	protected boolean doingUpdates = false;
	protected boolean onInsertRow = false;
	protected Hashtable updateValues = new Hashtable();
	private boolean usingOID = false;	// are we using the OID for the primary key?
	private Vector primaryKeys;    // list of primary keys
	private int numKeys = 0;
	private boolean singleTable = false;
	protected String tableName = null;
	protected PreparedStatement updateStatement = null;
	protected PreparedStatement insertStatement = null;
	protected PreparedStatement deleteStatement = null;
	private PreparedStatement selectStatement = null;

  
	public AbstractJdbc2ResultSet(BaseStatement statement, Field[] fields, Vector tuples, String status, int updateCount, long insertOID)
	{
		super (statement, fields, tuples, status, updateCount, insertOID);
	}

	public java.net.URL getURL(int columnIndex) throws SQLException
	{
		return null;
	}


	public java.net.URL getURL(String columnName) throws SQLException
	{
		return null;
	}


	/*
	 * Get the value of a column in the current row as a Java object
	 *
	 * <p>This method will return the value of the given column as a
	 * Java object.  The type of the Java object will be the default
	 * Java Object type corresponding to the column's SQL type, following
	 * the mapping specified in the JDBC specification.
	 *
	 * <p>This method may also be used to read database specific abstract
	 * data types.
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return a Object holding the column value
	 * @exception SQLException if a database access error occurs
	 */
	public Object getObject(int columnIndex) throws SQLException
	{
		Field field;

		checkResultSet( columnIndex );

		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		field = fields[columnIndex - 1];

		// some fields can be null, mainly from those returned by MetaData methods
		if (field == null)
		{
			wasNullFlag = true;
			return null;
		}

		switch (field.getSQLType())
		{
			case Types.BIT:
				return getBoolean(columnIndex) ? Boolean.TRUE : Boolean.FALSE;

			case Types.SMALLINT:
				return new Short(getShort(columnIndex));

			case Types.INTEGER:
				return new Integer(getInt(columnIndex));

			case Types.BIGINT:
				return new Long(getLong(columnIndex));

			case Types.NUMERIC:
				return getBigDecimal
					   (columnIndex, (field.getMod() == -1) ? -1 : ((field.getMod() - 4) & 0xffff));

			case Types.REAL:
				return new Float(getFloat(columnIndex));

			case Types.DOUBLE:
				return new Double(getDouble(columnIndex));

			case Types.CHAR:
			case Types.VARCHAR:
				return getString(columnIndex);

			case Types.DATE:
				return getDate(columnIndex);

			case Types.TIME:
				return getTime(columnIndex);

			case Types.TIMESTAMP:
				return getTimestamp(columnIndex);

			case Types.BINARY:
			case Types.VARBINARY:
				return getBytes(columnIndex);

			case Types.ARRAY:
				return getArray(columnIndex);

			default:
				String type = field.getPGType();

				// if the backend doesn't know the type then coerce to String
				if (type.equals("unknown"))
				{
					return getString(columnIndex);
				}
                                // Specialized support for ref cursors is neater.
                                else if (type.equals("refcursor"))
                                {
                                        String cursorName = getString(columnIndex);
                                        return statement.createRefCursorResultSet(cursorName);
                                }
				else
				{
					return connection.getObject(field.getPGType(), getString(columnIndex));
				}
		}
	}


	public boolean absolute(int index) throws SQLException
	{
		// index is 1-based, but internally we use 0-based indices
		int internalIndex;

		if (index == 0)
			throw new SQLException("Cannot move to index of 0");

		final int rows_size = rows.size();

		//if index<0, count from the end of the result set, but check
		//to be sure that it is not beyond the first index
		if (index < 0)
		{
			if (index >= -rows_size)
				internalIndex = rows_size + index;
			else
			{
				beforeFirst();
				return false;
			}
		}
		else
		{
			//must be the case that index>0,
			//find the correct place, assuming that
			//the index is not too large
			if (index <= rows_size)
				internalIndex = index - 1;
			else
			{
				afterLast();
				return false;
			}
		}

		current_row = internalIndex;
		this_row = (byte[][]) rows.elementAt(internalIndex);

		rowBuffer = new byte[this_row.length][];
		System.arraycopy(this_row, 0, rowBuffer, 0, this_row.length);
		onInsertRow = false;

		return true;
	}


	public void afterLast() throws SQLException
	{
		final int rows_size = rows.size();
		if (rows_size > 0)
			current_row = rows_size;

		onInsertRow = false;
		this_row = null;
		rowBuffer = null;
	}


	public void beforeFirst() throws SQLException
	{
		if (rows.size() > 0)
			current_row = -1;

		onInsertRow = false;
		this_row = null;
		rowBuffer = null;
	}


	public boolean first() throws SQLException
	{
		if (rows.size() <= 0)
			return false;

		current_row = 0;
		this_row = (byte[][]) rows.elementAt(current_row);

		rowBuffer = new byte[this_row.length][];
		System.arraycopy(this_row, 0, rowBuffer, 0, this_row.length);
		onInsertRow = false;

		return true;
	}


	public java.sql.Array getArray(String colName) throws SQLException
	{
		return getArray(findColumn(colName));
	}


	public java.sql.Array getArray(int i) throws SQLException
	{
		checkResultSet( i );

		wasNullFlag = (this_row[i - 1] == null);
		if (wasNullFlag)
			return null;

		if (i < 1 || i > fields.length)
			throw new PSQLException("postgresql.res.colrange", PSQLState.INVALID_PARAMETER_VALUE);
		return (java.sql.Array) new org.postgresql.jdbc2.Array( connection, i, fields[i - 1], this );
	}


	public java.math.BigDecimal getBigDecimal(int columnIndex) throws SQLException
	{
		return getBigDecimal(columnIndex, -1);
	}


	public java.math.BigDecimal getBigDecimal(String columnName) throws SQLException
	{
		return getBigDecimal(findColumn(columnName));
	}


	public Blob getBlob(String columnName) throws SQLException
	{
		return getBlob(findColumn(columnName));
	}


	public abstract Blob getBlob(int i) throws SQLException;


	public java.io.Reader getCharacterStream(String columnName) throws SQLException
	{
		return getCharacterStream(findColumn(columnName));
	}


	public java.io.Reader getCharacterStream(int i) throws SQLException
	{
		checkResultSet( i );
		wasNullFlag = (this_row[i - 1] == null);
		if (wasNullFlag)
			return null;

		if (((AbstractJdbc2Connection) connection).haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports AsciiStream for all the PG text types
			//As the spec/javadoc for this method indicate this is to be used for
			//large text values (i.e. LONGVARCHAR)	PG doesn't have a separate
			//long string datatype, but with toast the text datatype is capable of
			//handling very large values.  Thus the implementation ends up calling
			//getString() since there is no current way to stream the value from the server
			return new CharArrayReader(getString(i).toCharArray());
		}
		else
		{
			// In 7.1 Handle as BLOBS so return the LargeObject input stream
			Encoding encoding = connection.getEncoding();
			InputStream input = getBinaryStream(i);
			return encoding.getDecodingReader(input);
		}
	}


	public Clob getClob(String columnName) throws SQLException
	{
		return getClob(findColumn(columnName));
	}


	public abstract Clob getClob(int i) throws SQLException;


	public int getConcurrency() throws SQLException
	{
		if (statement == null)
			return java.sql.ResultSet.CONCUR_READ_ONLY;
		return statement.getResultSetConcurrency();
	}


	public java.sql.Date getDate(int i, java.util.Calendar cal) throws SQLException
	{
		// If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getDate()?
		// for now...
		return getDate(i);
	}


	public Time getTime(int i, java.util.Calendar cal) throws SQLException
	{
		// If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getTime()?
		// for now...
		return getTime(i);
	}


	public Timestamp getTimestamp(int i, java.util.Calendar cal) throws SQLException
	{
		// If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getDate()?
		// for now...
		return getTimestamp(i);
	}


	public java.sql.Date getDate(String c, java.util.Calendar cal) throws SQLException
	{
		return getDate(findColumn(c), cal);
	}


	public Time getTime(String c, java.util.Calendar cal) throws SQLException
	{
		return getTime(findColumn(c), cal);
	}


	public Timestamp getTimestamp(String c, java.util.Calendar cal) throws SQLException
	{
		return getTimestamp(findColumn(c), cal);
	}


	public int getFetchDirection() throws SQLException
	{
		//PostgreSQL normally sends rows first->last
		return java.sql.ResultSet.FETCH_FORWARD;
	}


	public Object getObject(String columnName, java.util.Map map) throws SQLException
	{
		return getObject(findColumn(columnName), map);
	}


	/*
	 * This checks against map for the type of column i, and if found returns
	 * an object based on that mapping. The class must implement the SQLData
	 * interface.
	 */
	public Object getObject(int i, java.util.Map map) throws SQLException
	{
		throw org.postgresql.Driver.notImplemented();
	}


	public Ref getRef(String columnName) throws SQLException
	{
		return getRef(findColumn(columnName));
	}


	public Ref getRef(int i) throws SQLException
	{
		//The backend doesn't yet have SQL3 REF types
		throw new PSQLException("postgresql.psqlnotimp", PSQLState.NOT_IMPLEMENTED);
	}


	public int getRow() throws SQLException
	{
		final int rows_size = rows.size();

		if (current_row < 0 || current_row >= rows_size)
			return 0;

		return current_row + 1;
	}


	// This one needs some thought, as not all ResultSets come from a statement
	public Statement getStatement() throws SQLException
	{
		return (Statement) statement;
	}


	public int getType() throws SQLException
	{
		// This implementation allows scrolling but is not able to
		// see any changes. Sub-classes may overide this to return a more
		// meaningful result.
		return java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE;
	}


	public boolean isAfterLast() throws SQLException
	{
		final int rows_size = rows.size();
		return (current_row >= rows_size && rows_size > 0);
	}


	public boolean isBeforeFirst() throws SQLException
	{
		return (current_row < 0 && rows.size() > 0);
	}


	public boolean isFirst() throws SQLException
	{
		return (current_row == 0 && rows.size() >= 0);
	}


	public boolean isLast() throws SQLException
	{
		final int rows_size = rows.size();
		return (current_row == rows_size - 1 && rows_size > 0);
	}


	public boolean last() throws SQLException
	{
		final int rows_size = rows.size();
		if (rows_size <= 0)
			return false;

		current_row = rows_size - 1;
		this_row = (byte[][]) rows.elementAt(current_row);

		rowBuffer = new byte[this_row.length][];
		System.arraycopy(this_row, 0, rowBuffer, 0, this_row.length);
		onInsertRow = false;

		return true;
	}


	public boolean previous() throws SQLException
	{
		if (current_row-1 < 0) {
			current_row = -1;
			this_row = null;
			rowBuffer = null;
			return false;
		} else {
			current_row--;
		}
		this_row = (byte[][]) rows.elementAt(current_row);
		rowBuffer = new byte[this_row.length][];
		System.arraycopy(this_row, 0, rowBuffer, 0, this_row.length);
		return true;
	}


	public boolean relative(int rows) throws SQLException
	{
		//have to add 1 since absolute expects a 1-based index
		return absolute(current_row + 1 + rows);
	}


	public void setFetchDirection(int direction) throws SQLException
	{
		throw new PSQLException("postgresql.psqlnotimp", PSQLState.NOT_IMPLEMENTED);
	}


	public synchronized void cancelRowUpdates()
	throws SQLException
	{
		if (doingUpdates)
		{
			doingUpdates = false;

			clearRowBuffer(true);
		}
	}