javatools.database
Class ResultIterator<T>

java.lang.Object
  javatools.datatypes.PeekIterator<T>
      javatools.database.ResultIterator<T>

All Implemented Interfaces:

java.io.Closeable, java.lang.Iterable<T>, java.util.Iterator<T>

public class ResultIterator<T>
extends PeekIterator<T>

This class is part of the Java Tools (see http://mpii.de/yago-naga/javatools). It is licensed under the Creative Commons Attribution License (see http://creativecommons.org/licenses/by/3.0) by the YAGO-NAGA team (see http://mpii.de/yago-naga). This class wraps a ResultSet into an Iterator over a given Class. It requires a method that can wrap a row of a ResultSet into an object of the given class.
Example:

  // We need this class to define how to construct an Employer from a table row
  public static class EmployerWrapper implements ResultWrapper<Employer> {

     // Wraps the current row in a ResultSet into an Employer
     public Employer wrap(ResultSet r) {  
       return(new Employer(r.getString(1),r.getDouble(2)); 
     }

  }

  Database d=new OracleDatabase("scott","tiger");
  for(Employer e : d.query("SELECT * FROM employers WHERE salary>1000",
                           new EmployerConstructor())) {
     System.out.println(e);
  }
  

Nested Class Summary

static interface

ResultIterator.ResultWrapper<T> Wraps the current row in a ResultSet into a T

Nested classes/interfaces inherited from class javatools.datatypes.PeekIterator

PeekIterator.ElementaryPeekIterator<T>, PeekIterator.SimplePeekIterator<T>

Field Summary

static ResultIterator.ResultWrapper<java.lang.Boolean>	BooleanWrapper ResultWrapper for a single Boolean column
static ResultIterator.ResultWrapper<java.lang.Double[]>	DoublesWrapper ResultWrapper for several Doubles.
static ResultIterator.ResultWrapper<java.lang.Double>	DoubleWrapper ResultWrapper for a single Double column.
static ResultIterator.ResultWrapper<java.lang.Integer[]>	IntegersWrapper ResultWrapper for several Integers.
static ResultIterator.ResultWrapper<java.lang.Integer>	IntegerWrapper ResultWrapper for a single Integer column
static ResultIterator.ResultWrapper<java.lang.Long>	LongWrapper ResultWrapper for a single Long column.
static ResultIterator.ResultWrapper<java.lang.String[]>	StringsWrapper ResultWrapper for String columns
static ResultIterator.ResultWrapper<java.lang.String>	StringWrapper ResultWrapper for a single String column

Fields inherited from class javatools.datatypes.PeekIterator

closed, initialized, next

Constructor Summary

ResultIterator(java.sql.ResultSet s, ResultIterator.ResultWrapper<T> cons)
Creates a ResultIterator for a ResultSet

Method Summary

void	close() Closes the resultset and the underlying statement
void	finalize() Closes the resultset
T	internalNext() Returns the next or NULL if no next element is available

Methods inherited from class javatools.datatypes.PeekIterator

asList, asList, asSet, asSet, asSet, emptyIterator, hasNext, iterator, list, list, main, next, nextOrNull, numElements, numElements, peek, remove, toString, toString, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

BooleanWrapper

public static final ResultIterator.ResultWrapper<java.lang.Boolean> BooleanWrapper

ResultWrapper for a single Boolean column

StringWrapper

public static final ResultIterator.ResultWrapper<java.lang.String> StringWrapper

ResultWrapper for a single String column

StringsWrapper

public static final ResultIterator.ResultWrapper<java.lang.String[]> StringsWrapper

ResultWrapper for String columns

LongWrapper

public static final ResultIterator.ResultWrapper<java.lang.Long> LongWrapper

ResultWrapper for a single Long column. Returns NULL for NULL

DoubleWrapper

public static final ResultIterator.ResultWrapper<java.lang.Double> DoubleWrapper

ResultWrapper for a single Double column. Returns NULL for NULL

DoublesWrapper

public static final ResultIterator.ResultWrapper<java.lang.Double[]> DoublesWrapper

ResultWrapper for several Doubles. Returns NULL for NULL

IntegerWrapper

public static final ResultIterator.ResultWrapper<java.lang.Integer> IntegerWrapper

ResultWrapper for a single Integer column

IntegersWrapper

public static final ResultIterator.ResultWrapper<java.lang.Integer[]> IntegersWrapper

ResultWrapper for several Integers. Returns NULL for NULL

Constructor Detail

ResultIterator

public ResultIterator(java.sql.ResultSet s,
                      ResultIterator.ResultWrapper<T> cons)

Creates a ResultIterator for a ResultSet

Method Detail

internalNext

public T internalNext()
               throws java.lang.Exception

Description copied from class: PeekIterator

Returns the next or NULL if no next element is available

Throws:

java.lang.Exception

close

public void close()

Closes the resultset and the underlying statement

Specified by:

close in interface java.io.Closeable

Overrides:

close in class PeekIterator<T>

finalize

public void finalize()

Closes the resultset

Overrides:

finalize in class java.lang.Object