sqlj.runtime.ref
Class ResultSetIterImpl

java.lang.Object
  |
  +--sqlj.runtime.ref.ResultSetIterImpl

Direct Known Subclasses:

ScrollableResultSetIterImpl

public class ResultSetIterImpl

extends java.lang.Object

implements ResultSetIterator

The result set iter(ator) impl(ementation) class implements the functionality of both a positioned iterator, and a named iterator. However, it does not directly implement either of these interfaces. Rather, the translator will generate iterator classes which subclass this class and implement only the iterator interface that they were declared to implement (thus avoiding iterators which appear to be both positional and named).

This class is used internally by the reference translator code generation. It is expected that clients will not directly reference this class.

See Also:

PositionedIterator, NamedIterator, ForUpdate

Field Summary

protected sqlj.runtime.profile.RTResultSet

resultSet The underlying reference runtime result set

Constructor Summary

ResultSetIterImpl(sqlj.runtime.profile.RTResultSet rs)
Creates a new result set iter impl object that uses data found in the passed result set.

ResultSetIterImpl(sqlj.runtime.profile.RTResultSet rs, int numColumns)
Creates a new result set iter impl object that uses data found in the passed result set.

Method Summary

static void	checkColumns(sqlj.runtime.profile.RTResultSet rs, int expectedColumns) Verifies that the passed result set has the passed expected number of columns.
void	clearWarnings() After this call getWarnings returns null until a new warning is reported for this iterator.
void	close() closes this iterator and the underlying result set.
boolean	endFetch() Returns false if currently on a row, true otherwise.
protected void	finalize() finalizes the super object and calls close if this iterator has not already been closed.
protected int	findColumn(java.lang.String name) Returns the index associated with the passed column name on the underlying result set.
java.lang.String	getCursorName() Returns the cursor name of the underlying result set.
int	getFetchSize() Retrieves the number of rows that is the current fetch size for this iterator object.
java.sql.ResultSet	getResultSet() Returns the JDBC result set associated with this iterator, if any.
int	getSensitivity() Returns the sensitivity of this iterator object.
java.sql.SQLWarning	getWarnings() Returns the first warning reported by calls on this iterator is returned.
boolean	isClosed() Returns true if this iterator has been closed, false otherwise.
boolean	next() Fetches the next row in the iterator and returns true if there was a row to fetch, false otherwise.
void	setFetchSize(int rows) Gives the SQLJ runtime a hint as to the number of rows that should be fetched when more rows are needed from this iterator object.

Methods inherited from class java.lang.Object

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

Field Detail

resultSet

protected sqlj.runtime.profile.RTResultSet resultSet

The underlying reference runtime result set

Constructor Detail

ResultSetIterImpl

public ResultSetIterImpl(sqlj.runtime.profile.RTResultSet rs)

Creates a new result set iter impl object that uses data found in the passed result set.

ResultSetIterImpl

public ResultSetIterImpl(sqlj.runtime.profile.RTResultSet rs,
                         int numColumns)
                  throws java.sql.SQLException

Creates a new result set iter impl object that uses data found in the passed result set. Verifies that the passed result set contains the same number of columns as is passed in the numColumns parameter.

Note: If a SQLException is raised by the constructor, the passed result set is automatically closed.

Parameters:

rs - the underlying result set

numColumns - the expected number of columns in the result set

Throws:

java.sql.SQLException - if the result set does not contain the expected number of columns

See Also:

checkColumns(sqlj.runtime.profile.RTResultSet, int)

Method Detail

checkColumns

public static void checkColumns(sqlj.runtime.profile.RTResultSet rs,
                                int expectedColumns)
                         throws java.sql.SQLException

Verifies that the passed result set has the passed expected number of columns. An exception is raised if not. This method is provided for uniformity of error reporting between select..into and iterators.

Parameters:

rs - the result set to check.

expectedColumns - the expected number of columns in the result set.

Throws:

java.sql.SQLException - if the result set does not have the expected number of columns.

findColumn

protected int findColumn(java.lang.String name)
                  throws java.sql.SQLException

Returns the index associated with the passed column name on the underlying result set. Throws an exception if the column name does not exist. Used by generated named iterators for uniform treatment of findColumn. Assumes that this method is called during construction

Note: We assume that this method is only called during subclass construction, and thus if a SQLException is raised during this method, the underlying result set is automatically closed.

Parameters:

name - the name of the column in question

Throws:

java.sql.SQLException - if the column cannot be found. Underlying result set is closed in this case.

getResultSet

public java.sql.ResultSet getResultSet()
                                throws java.sql.SQLException

Returns the JDBC result set associated with this iterator, if any.

Specified by:

getResultSet in interface ResultSetIterator

Throws:

java.sql.SQLException - if there is no JDBC result set associated with this iterator.

close

public void close()
           throws java.sql.SQLException

closes this iterator and the underlying result set.

Specified by:

close in interface ResultSetIterator

Throws:

java.sql.SQLException - if an error occurs during close

See Also:

ResultSetIterator.close()

isClosed

public boolean isClosed()
                 throws java.sql.SQLException

Returns true if this iterator has been closed, false otherwise.

Specified by:

isClosed in interface ResultSetIterator

Throws:

java.sql.SQLException - if a database access error occurs.

See Also:

ResultSetIterator.isClosed()

getCursorName

public java.lang.String getCursorName()
                               throws java.sql.SQLException

Returns the cursor name of the underlying result set.

Throws:

java.sql.SQLException - if the underlying result set does not have a cursor name.

See Also:

ForUpdate.getCursorName()

endFetch

public boolean endFetch()
                 throws java.sql.SQLException

Returns false if currently on a row, true otherwise. Provides a termination condition for FETCH..INTO statements, as endFetch will be true after the last row has been FETCHed.

Throws:

java.sql.SQLException - if a database access error occurs.

See Also:

PositionedIterator.endFetch()

next

public boolean next()
             throws java.sql.SQLException

Fetches the next row in the iterator and returns true if there was a row to fetch, false otherwise.

Specified by:

next in interface ResultSetIterator

Throws:

java.sql.SQLException - if an error occurs in the underlying result set's call to next.

See Also:

ResultSetIterator.next()

getWarnings

public java.sql.SQLWarning getWarnings()
                                throws java.sql.SQLException

Returns the first warning reported by calls on this iterator is returned. Subsequent iterator warings will be chained to this SQLWarning.

Specified by:

getWarnings in interface ResultSetIterator

Throws:

java.sql.SQLException - if a database access error occurs.

See Also:

ResultSetIterator.getWarnings()

clearWarnings

public void clearWarnings()
                   throws java.sql.SQLException

After this call getWarnings returns null until a new warning is reported for this iterator.

Specified by:

clearWarnings in interface ResultSetIterator

Throws:

java.sql.SQLException - if a database-access error occurs.

finalize

protected void finalize()
                 throws java.lang.Throwable

finalizes the super object and calls close if this iterator has not already been closed.

Throws:

java.lang.Throwable - if an error occurs during finalization

Overrides:

finalize in class java.lang.Object

See Also:

close(), isClosed()

getFetchSize

public int getFetchSize()
                 throws java.sql.SQLException

Retrieves the number of rows that is the current fetch size for this iterator object. If this iterator object has not set a fetch size by calling the method setFetchSize, or has set a fetch size of zero, then the value returned is implementation-dependent.

Specified by:

getFetchSize in interface ResultSetIterator

Returns:

the default fetch size for the iterator object.

Throws:

java.sql.SQLException - if a database access error occurs.

setFetchSize

public void setFetchSize(int rows)
                  throws java.sql.SQLException

Gives the SQLJ runtime a hint as to the number of rows that should be fetched when more rows are needed from this iterator object. If the value specified is zero, then the the runtime is free to choose an implementation-dependent fetch size.

Specified by:

setFetchSize in interface ResultSetIterator

Parameters:

rows - the default fetch size for result sets generated from this iterator object.

Throws:

java.sql.SQLException - if a database access error occurs, or the condition 0 <= rows <= ECtxt.getMaxRows() is not satisfied, where ECtxt is the ExecutionContext object that was used to create this iterator object.

getSensitivity

public int getSensitivity()
                   throws java.sql.SQLException

Returns the sensitivity of this iterator object. The type is determined by the declaration of the iterator object and by the SQLJ runtime implementation that created the iterator object.

Specified by:

getSensitivity in interface ResultSetIterator

Returns:

• ResultSetIterator.SENSITIVE - if this iterator object was declared with the <predefined iterator with keyword> sensitivity and a corresponding <with value> SENSITIVE, and the SQLJ runtime that created this iterator object supports sensitive iterators.
• ResultSetIterator.INSENSITIVE - if this iterator object object was declared with the <predefined iterator with keyword> sensitivity and a corresponding <with value> INSENSITIVE, and the SQLJ runtime that created this iterator object supports insensitive iterators.
• ResultSetIterator.ASENSITIVE - if this iterator object was declared with the <predefined iterator with keyword> sensitivity and a corresponding <with value> ASENSITIVE.
• An implementation-dependent value otherwise.

Throws:

java.sql.SQLException - if a database access error occurs