de.mathema.pride
Class ResultIterator

java.lang.Object
  de.mathema.pride.ResultIterator

public class ResultIterator
extends java.lang.Object

Helper class to iterate thru a list of results from a query. ResultIterators are initialized be the Database class and provide their results step-by-step in the same Entity object. A typical usage may look like this:

    try {
       Person p = new Person();
       ResultIterator iter = p.queryAll();
       do {
          System.println(p.getName());
       } while(iter.next());
    }
    catch(NoResultsException nrx) {}
 

Author:

Jan Lessner

Field Summary

static int	COLUMN_STARTINDEX
protected java.sql.Connection	connection
protected Database	db
protected java.lang.Object	obj
protected RecordDescriptor	red
protected java.sql.ResultSet	results
static java.lang.String	REVISION_ID
protected java.sql.Statement	statement

Constructor Summary

ResultIterator(java.sql.Statement statement, java.sql.ResultSet rs, Database db, java.sql.Connection con)

ResultIterator(java.sql.Statement statement, java.sql.ResultSet rs, java.lang.Object obj, RecordDescriptor red, Database db, java.sql.Connection con)
Creates a new ResultIterator from an query.

Method Summary

void	close() Closes the iteration by closing the result set, the statement and the database connection passed in the constructor.
java.math.BigDecimal	getBigDecimal(int index)
java.math.BigDecimal	getBigDecimal(java.lang.String column)
java.sql.Date	getDate(int index)
int	getFetchSize() Returns the current fetch size for the underlying ResultSet
int	getInt(int index)
java.lang.Object	getObject() Returns the object, the ResultIterator writes its data to
java.sql.ResultSet	getResultSet() Returns the result set, the iterator is operating on.
boolean	isClosed() Returns true if this result iterator has been closed.
boolean	next() Fetches the next record from the result set and stores it in the entity object passed in the constructor.
void	setFetchSize(int size) Sets the fetch size for the underlying ResultSet
java.lang.Object[]	toArray() Like the function above but returns all data without limitation.
java.lang.Object[]	toArray(long maxResults) Like toArrayList(long) but returns the data as an array.
java.util.ArrayList	toArrayList() Like the function above but returns all data without size limitation.
java.util.ArrayList	toArrayList(long maxResults) Iterates through the complete result set and returns the data in an ArrayList.

Methods inherited from class java.lang.Object

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

Field Detail

COLUMN_STARTINDEX

public static final int COLUMN_STARTINDEX

See Also:

Constant Field Values

statement

protected java.sql.Statement statement

connection

protected java.sql.Connection connection

results

protected java.sql.ResultSet results

obj

protected java.lang.Object obj

red

protected RecordDescriptor red

db

protected Database db

REVISION_ID

public static final java.lang.String REVISION_ID

See Also:

Constant Field Values

Constructor Detail

ResultIterator

public ResultIterator(java.sql.Statement statement,
                      java.sql.ResultSet rs,
                      java.lang.Object obj,
                      RecordDescriptor red,
                      Database db,
                      java.sql.Connection con)

Creates a new ResultIterator from an query.

ResultIterator

public ResultIterator(java.sql.Statement statement,
                      java.sql.ResultSet rs,
                      Database db,
                      java.sql.Connection con)

Method Detail

getResultSet

public java.sql.ResultSet getResultSet()

Returns the result set, the iterator is operating on. This may be required to pass query results to standard reporting engines etc.

close

public void close()
           throws java.sql.SQLException

Closes the iteration by closing the result set, the statement and the database connection passed in the constructor. This function is only required when aborting an iteration. If the complete result set is expected, the iterator is closed automatically.

Throws:

java.sql.SQLException

isClosed

public boolean isClosed()

Returns true if this result iterator has been closed.

next

public boolean next()
             throws java.sql.SQLException

Fetches the next record from the result set and stores it in the entity object passed in the constructor. If there is no further data available, the iterator is closed.

Returns:

false, if there is no more data available.

Throws:

java.sql.SQLException - if accessing the query results fails

{@link - NoResultsException} if the iterator is already closed

getObject

public java.lang.Object getObject()

Returns the object, the ResultIterator writes its data to

toArrayList

public java.util.ArrayList toArrayList(long maxResults)
                                throws java.sql.SQLException

Iterates through the complete result set and returns the data in an ArrayList. The list contains clones of the iterator's operation object for each iteration step.

Parameters:

maxResults - The maximum number of results to collect. If maxResults is -1, the function returns all data from the underlying result set

Returns:

The assembled ArrayList

Throws:

java.lang.CloneNotSupportedException - if the operation object has no public clone method available

java.sql.SQLException - if there occurs a databaes error during iteration

toArrayList

public java.util.ArrayList toArrayList()
                                throws java.sql.SQLException

Like the function above but returns all data without size limitation. This function must be used with great care since the number of elements in a result set can be very large.

Throws:

java.sql.SQLException

toArray

public java.lang.Object[] toArray(long maxResults)
                           throws java.sql.SQLException

Like toArrayList(long) but returns the data as an array. The runtime type of the array's elements is the one of the iterator's operation object.

Throws:

java.sql.SQLException

toArray

public java.lang.Object[] toArray()
                           throws java.sql.SQLException

Like the function above but returns all data without limitation. This function must be used with great care since the number of elements in a result set can be very large.

Throws:

java.sql.SQLException

getFetchSize

public int getFetchSize()
                 throws java.sql.SQLException

Returns the current fetch size for the underlying ResultSet

Throws:

java.sql.SQLException

setFetchSize

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

Sets the fetch size for the underlying ResultSet

Throws:

java.sql.SQLException

getInt

public int getInt(int index)
           throws java.sql.SQLException

Throws:

java.sql.SQLException

getBigDecimal

public java.math.BigDecimal getBigDecimal(int index)
                                   throws java.sql.SQLException

Throws:

java.sql.SQLException

getBigDecimal

public java.math.BigDecimal getBigDecimal(java.lang.String column)
                                   throws java.sql.SQLException

Throws:

java.sql.SQLException

getDate

public java.sql.Date getDate(int index)
                      throws java.sql.SQLException

Throws:

java.sql.SQLException