org.geotools.data.jdbc
Class ResultSetAttributeIO

java.lang.Object
  org.geotools.data.AbstractAttributeIO
      org.geotools.data.jdbc.ResultSetAttributeIO

All Implemented Interfaces:

AttributeReader, AttributeWriter, QueryDataListener

public class ResultSetAttributeIO

extends AbstractAttributeIO

implements QueryDataListener, AttributeWriter, AttributeReader

Provides an AttriuteReader over a result set limiting the columns to a defined range. This uses the default SQL->Java type mappings of the result set.

Ranges are based on JDBC ResultSet column indexes which begin at 1

This reader does not handle any geometries.

Author:

Sean Geoghegan, Defence Science and Technology Organisation

Field Summary

Fields inherited from class org.geotools.data.AbstractAttributeIO

metaData

Constructor Summary

ResultSetAttributeIO(AttributeType[] metadata, JDBCDataStore.QueryData querydata, int startColumn, int endColumn)
Creates a new RangedResultSetAttributeReader.

Method Summary

void	close() This closes the QueryData object that the Read was constructed with.
boolean	hasNext() Returns true if there are more rows.
boolean	isClosed()
void	next() Moves to the next row in the result set.
void	queryDataClosed(JDBCDataStore.QueryData queryData)
java.lang.Object	read(int i) Reads an attribute from the given column in the current row.
void	rowDeleted(JDBCDataStore.QueryData queryData)
void	write(int position, java.lang.Object attribute) This writes the attribute to the position within the ResultSet.

Methods inherited from class org.geotools.data.AbstractAttributeIO

copy, getAttributeCount, getAttributeType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.geotools.data.AttributeWriter

getAttributeCount, getAttributeType

Methods inherited from interface org.geotools.data.AttributeReader

getAttributeCount, getAttributeType

Constructor Detail

ResultSetAttributeIO

public ResultSetAttributeIO(AttributeType[] metadata,
                            JDBCDataStore.QueryData querydata,
                            int startColumn,
                            int endColumn)

Creates a new RangedResultSetAttributeReader. This will read all the attributes in the columns from startColumn to endColumn - 1. These indexes are 1 based.

Parameters:

metadata - The meta data of the columns.

startColumn - The starting column, inclusive.

endColumn - The ending index, exclusive.

Method Detail

close

public void close()
           throws java.io.IOException

This closes the QueryData object that the Read was constructed with. Closing this object will force all other Readers using the queryData object to be notified of the close if they are registered as QueryDataListeners of the queryData object.

This method will also set a flag to indicate that the results have been closed elsewhere and future calls to the read methods of the reader will throw errors.

Specified by:

close in interface AttributeWriter

Throws:

java.io.IOException - This will never be thrown by this class.

See Also:

AttributeReader.close()

hasNext

public boolean hasNext()
                throws java.io.IOException

Returns true if there are more rows.

Specified by:

hasNext in interface AttributeWriter

Returns:

Throws:

java.io.IOException - This will only occur if an SQLException occurs on the result set.

See Also:

AttributeReader.hasNext()

next

public void next()
          throws java.io.IOException

Moves to the next row in the result set.

Specified by:

next in interface AttributeWriter

Throws:

java.io.IOException

See Also:

AttributeReader.next()

read

public java.lang.Object read(int i)
                      throws java.io.IOException,
                             java.lang.ArrayIndexOutOfBoundsException

Reads an attribute from the given column in the current row.

Specified by:

read in interface AttributeReader

Parameters:

i - The zero based index into the attributes of this attribute reader. This index is based on the index of the attribute in the array of AttributeTypes this Reader uses as meta data. The index is internally mapped to the result set column index so this is transparent to the user.

Returns:

Object Attribute at given index

Throws:

java.io.IOException - If an error occurs setting thr row or retreiving the value from the column or the Reader has previously bee closed.

java.lang.ArrayIndexOutOfBoundsException - If the index passed as i is greater than the number of attributes in the schema or outside the range of this reader. i is outside the range of the reader if (startColumn + i) < startColumn or (startColumn + i) >= endColumn.

See Also:

AttributeReader.read(int)

write

public void write(int position,
                  java.lang.Object attribute)
           throws java.io.IOException

This writes the attribute to the position within the ResultSet.

Currently uses the update methods of result set to write the data.

Issues to consider:
• Where should updateRow() and insertRow() be called?
• Who should handle the positioning of the cursor. This can either be done in this method or by the FeatureWriter. If it is done here we need to check for insertion. This could be done by checking if isAfterLast is true, in which case we go to the insertRow.
• Where should moveToInsertRow() and moveToCurrentRow() be called??

Specified by:

write in interface AttributeWriter

Throws:

java.io.IOException

See Also:

AttributeWriter.write(int, java.lang.Object)

queryDataClosed

public void queryDataClosed(JDBCDataStore.QueryData queryData)

Specified by:

queryDataClosed in interface QueryDataListener

rowDeleted

public void rowDeleted(JDBCDataStore.QueryData queryData)

Specified by:

rowDeleted in interface QueryDataListener

Parameters:

queryData -

See Also:

QueryDataListener.rowDeleted(org.geotools.data.jdbc.JDBCDataStore.QueryData)

isClosed

public boolean isClosed()