tyweed420
asked on
trying to ake a clone of my queueArray however it is not cloning the entire array?
I have implemented a QueueArray and now i'm simply trying to make a clone , however there is something missing in my clone() in order to get the complete copy of my existing queueArray.
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
//i need something here to somehow clone the array portion as well yes?
return queue;
}
============ entire code=====
/**
* Array-based implementation of the queue.
* @author Mark Allen Weiss
*/
public class QueueArray implements Cloneable
{
/**
* Construct the queue.
*/
public QueueArray( )
{
this( DEFAULT_CAPACITY );
}
/**
* Construct the queue.
*/
public QueueArray( int capacity )
{
theArray = new int[ capacity ];
makeEmpty( );
}
/**
* Test if the queue is logically empty.
* @return true if empty, false otherwise.
*/
public boolean isEmpty( )
{
return currentSize == 0;
}
/**
* Test if the queue is logically full.
* @return true if full, false otherwise.
*/
public boolean isFull( )
{
return currentSize == theArray.length;
}
/**
* Make the queue logically empty.
*/
public void makeEmpty( )
{
currentSize = 0;
front = 0;
back = -1;
}
/**
* Get the least recently inserted item in the queue.
* Does not alter the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int getFront( )
{
if( isEmpty( ) )
return -1;
return theArray[ front ];
}
/**
* Return and remove the least recently inserted item from the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int dequeue( )
{
if( isEmpty( ) )
return -1;
currentSize--;
int frontItem = theArray[ front ];
theArray[ front ] = -1;
front = increment( front );
return frontItem;
}
/**
* Insert a new item into the queue.
* @param x the item to insert.
* @exception Overflow if queue is full.
*/
public void enqueue( int x )
{
if( isFull( ) )
System.out.println("queue is full");
back = increment( back );
theArray[ back ] = x;
currentSize++;
}
/**
* Internal method to increment with wraparound.
* @param x any index in theArray's range.
* @return x+1, or 0, if x is at the end of theArray.
*/
private int increment( int x )
{
if( ++x == theArray.length )
x = 0;
return x;
}
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return queue;
}
private int [ ] theArray;
private int currentSize;
private int front;
private int back;
static final int DEFAULT_CAPACITY = 10;
public static void main( String [ ] args )
{
QueueArray q = new QueueArray( );
QueueArray temp = new QueueArray( );
try
{
q.enqueue( 1 );
q.enqueue( 2 );
q.enqueue( 3 );
temp = (QueueArray) q.clone();
temp.enqueue(4);
System.out.println( q.getFront() + "test") ;
}
catch( Exception e ) { System.out.println( "Unexpected overflow" ); }
while( !q.isEmpty( ) )
System.out.println( q.dequeue( ) );
System.out.println("=");
while( !temp.isEmpty( ) )
System.out.println( temp.dequeue( ) );
}
}
========================
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
//i need something here to somehow clone the array portion as well yes?
return queue;
}
============ entire code=====
/**
* Array-based implementation of the queue.
* @author Mark Allen Weiss
*/
public class QueueArray implements Cloneable
{
/**
* Construct the queue.
*/
public QueueArray( )
{
this( DEFAULT_CAPACITY );
}
/**
* Construct the queue.
*/
public QueueArray( int capacity )
{
theArray = new int[ capacity ];
makeEmpty( );
}
/**
* Test if the queue is logically empty.
* @return true if empty, false otherwise.
*/
public boolean isEmpty( )
{
return currentSize == 0;
}
/**
* Test if the queue is logically full.
* @return true if full, false otherwise.
*/
public boolean isFull( )
{
return currentSize == theArray.length;
}
/**
* Make the queue logically empty.
*/
public void makeEmpty( )
{
currentSize = 0;
front = 0;
back = -1;
}
/**
* Get the least recently inserted item in the queue.
* Does not alter the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int getFront( )
{
if( isEmpty( ) )
return -1;
return theArray[ front ];
}
/**
* Return and remove the least recently inserted item from the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int dequeue( )
{
if( isEmpty( ) )
return -1;
currentSize--;
int frontItem = theArray[ front ];
theArray[ front ] = -1;
front = increment( front );
return frontItem;
}
/**
* Insert a new item into the queue.
* @param x the item to insert.
* @exception Overflow if queue is full.
*/
public void enqueue( int x )
{
if( isFull( ) )
System.out.println("queue is full");
back = increment( back );
theArray[ back ] = x;
currentSize++;
}
/**
* Internal method to increment with wraparound.
* @param x any index in theArray's range.
* @return x+1, or 0, if x is at the end of theArray.
*/
private int increment( int x )
{
if( ++x == theArray.length )
x = 0;
return x;
}
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return queue;
}
private int [ ] theArray;
private int currentSize;
private int front;
private int back;
static final int DEFAULT_CAPACITY = 10;
public static void main( String [ ] args )
{
QueueArray q = new QueueArray( );
QueueArray temp = new QueueArray( );
try
{
q.enqueue( 1 );
q.enqueue( 2 );
q.enqueue( 3 );
temp = (QueueArray) q.clone();
temp.enqueue(4);
System.out.println( q.getFront() + "test") ;
}
catch( Exception e ) { System.out.println( "Unexpected overflow" ); }
while( !q.isEmpty( ) )
System.out.println( q.dequeue( ) );
System.out.println("=");
while( !temp.isEmpty( ) )
System.out.println( temp.dequeue( ) );
}
}
========================
SOLUTION
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ASKER
Ok, im trying to do a deep clone and having no luck. I'v done research on this site and tried using a class cloner() . however the cloner method is throwing my catch statement in main? could someone please help me get this queue to become deep cloned ! i'll increase points.
my code
/**
* Array-based implementation of the queue.
* @author Mark Allen Weiss
*/
import java.io.ByteArrayOutputStr
import java.io.ByteArrayInputStre
import java.io.ObjectOutputStream
import java.io.ObjectInputStream;
public class QueueArray implements Cloneable
{
/**
* Construct the queue.
*/
public QueueArray( )
{
this( DEFAULT_CAPACITY );
}
/**
* Construct the queue.
*/
public QueueArray( int capacity )
{
theArray = new int[ capacity ];
makeEmpty( );
}
/**
* Test if the queue is logically empty.
* @return true if empty, false otherwise.
*/
public boolean isEmpty( )
{
return currentSize == 0;
}
/**
* Test if the queue is logically full.
* @return true if full, false otherwise.
*/
public boolean isFull( )
{
return currentSize == theArray.length;
}
/**
* Make the queue logically empty.
*/
public void makeEmpty( )
{
currentSize = 0;
front = 0;
back = -1;
}
/**
* Get the least recently inserted item in the queue.
* Does not alter the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int getFront( )
{
if( isEmpty( ) )
return -1;
return theArray[ front ];
}
/**
* Return and remove the least recently inserted item from the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int dequeue( )
{
if( isEmpty( ) )
return -1;
currentSize--;
int frontItem = theArray[ front ];
theArray[ front ] = -1;
front = increment( front );
return frontItem;
}
/**
* Insert a new item into the queue.
* @param x the item to insert.
* @exception Overflow if queue is full.
*/
public void enqueue( int x )
{
if( isFull( ) )
System.out.println("queue is full");
back = increment( back );
theArray[ back ] = x;
currentSize++;
}
/**
* Internal method to increment with wraparound.
* @param x any index in theArray's range.
* @return x+1, or 0, if x is at the end of theArray.
*/
private int increment( int x )
{
if( ++x == theArray.length )
x = 0;
return x;
}
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return queue;
}
public static Object cloneObject(Object o) throws Exception
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bOut);
out.writeObject(o);
ByteArrayInputStream bIn = new ByteArrayInputStream(bOut.
ObjectInputStream in = new ObjectInputStream(bIn);
return(in.readObject());
}
private int [ ] theArray;
private int currentSize;
private int front;
private int back;
static final int DEFAULT_CAPACITY = 10;
public static void main( String [ ] args )
{
QueueArray q = new QueueArray( );
QueueArray temp = new QueueArray( );
try
{
q.enqueue( 1 );
q.enqueue( 2 );
q.enqueue( 3 );
temp = (QueueArray)Cloner.cloneOb
temp.enqueue(4);
System.out.println( q.getFront() + "test") ;
}
catch( Exception e ) { System.out.println( "Unexpected overflow" ); } <=== im getting this unexpectedoverflow??
while( !q.isEmpty( ) )
System.out.println( q.dequeue( ) );
System.out.println("=");
while( !temp.isEmpty( ) )
System.out.println( temp.dequeue( ) );
}
}
class Cloner
{
private Cloner() {}
public static Object cloneObject(Object o) throws Exception
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bOut);
out.writeObject(o);
ByteArrayInputStream bIn =
new ByteArrayInputStream(bOut.
ObjectInputStream in = new ObjectInputStream(bIn);
return(in.readObject());
}
}
my code
/**
* Array-based implementation of the queue.
* @author Mark Allen Weiss
*/
import java.io.ByteArrayOutputStr
import java.io.ByteArrayInputStre
import java.io.ObjectOutputStream
import java.io.ObjectInputStream;
public class QueueArray implements Cloneable
{
/**
* Construct the queue.
*/
public QueueArray( )
{
this( DEFAULT_CAPACITY );
}
/**
* Construct the queue.
*/
public QueueArray( int capacity )
{
theArray = new int[ capacity ];
makeEmpty( );
}
/**
* Test if the queue is logically empty.
* @return true if empty, false otherwise.
*/
public boolean isEmpty( )
{
return currentSize == 0;
}
/**
* Test if the queue is logically full.
* @return true if full, false otherwise.
*/
public boolean isFull( )
{
return currentSize == theArray.length;
}
/**
* Make the queue logically empty.
*/
public void makeEmpty( )
{
currentSize = 0;
front = 0;
back = -1;
}
/**
* Get the least recently inserted item in the queue.
* Does not alter the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int getFront( )
{
if( isEmpty( ) )
return -1;
return theArray[ front ];
}
/**
* Return and remove the least recently inserted item from the queue.
* @return the least recently inserted item in the queue, or null, if empty.
*/
public int dequeue( )
{
if( isEmpty( ) )
return -1;
currentSize--;
int frontItem = theArray[ front ];
theArray[ front ] = -1;
front = increment( front );
return frontItem;
}
/**
* Insert a new item into the queue.
* @param x the item to insert.
* @exception Overflow if queue is full.
*/
public void enqueue( int x )
{
if( isFull( ) )
System.out.println("queue is full");
back = increment( back );
theArray[ back ] = x;
currentSize++;
}
/**
* Internal method to increment with wraparound.
* @param x any index in theArray's range.
* @return x+1, or 0, if x is at the end of theArray.
*/
private int increment( int x )
{
if( ++x == theArray.length )
x = 0;
return x;
}
public Object clone()
{
QueueArray queue = null;
try
{
queue = (QueueArray) super.clone();
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return queue;
}
public static Object cloneObject(Object o) throws Exception
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bOut);
out.writeObject(o);
ByteArrayInputStream bIn = new ByteArrayInputStream(bOut.
ObjectInputStream in = new ObjectInputStream(bIn);
return(in.readObject());
}
private int [ ] theArray;
private int currentSize;
private int front;
private int back;
static final int DEFAULT_CAPACITY = 10;
public static void main( String [ ] args )
{
QueueArray q = new QueueArray( );
QueueArray temp = new QueueArray( );
try
{
q.enqueue( 1 );
q.enqueue( 2 );
q.enqueue( 3 );
temp = (QueueArray)Cloner.cloneOb
temp.enqueue(4);
System.out.println( q.getFront() + "test") ;
}
catch( Exception e ) { System.out.println( "Unexpected overflow" ); } <=== im getting this unexpectedoverflow??
while( !q.isEmpty( ) )
System.out.println( q.dequeue( ) );
System.out.println("=");
while( !temp.isEmpty( ) )
System.out.println( temp.dequeue( ) );
}
}
class Cloner
{
private Cloner() {}
public static Object cloneObject(Object o) throws Exception
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bOut);
out.writeObject(o);
ByteArrayInputStream bIn =
new ByteArrayInputStream(bOut.
ObjectInputStream in = new ObjectInputStream(bIn);
return(in.readObject());
}
}
The reason is that QueueArray is not serializable;
either make it serilibale or
change your clone funcion as
public Object clone()
{
QueueArray copyQueue = null;
try
{
copyQueue = (QueueArray) super.clone();
copyQueue.theArray = new int[copyQueue.currentSize]
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return copyQueue;
}
<CE>
either make it serilibale or
change your clone funcion as
public Object clone()
{
QueueArray copyQueue = null;
try
{
copyQueue = (QueueArray) super.clone();
copyQueue.theArray = new int[copyQueue.currentSize]
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
}
catch (CloneNotSupportedExceptio
{
//This will never happen because this class is Clonable
return null; //Never get here
}
return copyQueue;
}
<CE>
<< <=== im getting this unexpectedoverflow??
The reason is that QueueArray is not serializable and it is throwing a java.io.NotSerializableExc
either make it serializable (i.e write a serializer/deserializer) for out.writeObject(o) for QueueArray requires a serializer.
The reason is that QueueArray is not serializable and it is throwing a java.io.NotSerializableExc
either make it serializable (i.e write a serializer/deserializer) for out.writeObject(o) for QueueArray requires a serializer.
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
>>
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
>>
It would actually be more efficient to use System.arraycopy
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
>>
It would actually be more efficient to use System.arraycopy
ASKER
Thank you, very much! i can move forward with my work!
tyweed420 can you explain why i got none of the points there to a question i answered?
ASKER
CEHJ : You need to make a deep copy, going into the object graph of the target
A: I knew i needed a deep copy i just didn't know how to implement it.
CEHJ:
>>
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
>>
It would actually be more efficient to use System.arraycopy
A: I just needed it to work and coding experts was able to write the entire clone method for me and compiled and worked great! I thought he deserved those points.
However, CEHJ you have helped me with many problems and do not want to anger you, I apologize. i'd be more than happy to give you some points for your responses. Hows a 100 points sound fair? I'll create a quick question answer it real fast i'll send the points your way. I want your continued help in my infinitly many questions i will ask in the near future. You are a cding "god" your input isd important to me.What you think :)
A: I knew i needed a deep copy i just didn't know how to implement it.
CEHJ:
>>
for(int i=0;i<copyQueue.currentSiz
copyQueue.theArray[i] = theArray[i];
>>
It would actually be more efficient to use System.arraycopy
A: I just needed it to work and coding experts was able to write the entire clone method for me and compiled and worked great! I thought he deserved those points.
However, CEHJ you have helped me with many problems and do not want to anger you, I apologize. i'd be more than happy to give you some points for your responses. Hows a 100 points sound fair? I'll create a quick question answer it real fast i'll send the points your way. I want your continued help in my infinitly many questions i will ask in the near future. You are a cding "god" your input isd important to me.What you think :)
Well i certainly don't object to CodingExperts getting points on this - s/he deserves them. It's just that i thought *some* points might have come my way, having answered the question ;-) I'd be happy with 50. I'll ask a page editor to help - so do nothing yet ;-)
8-)
tyweed420,
Could you also then award me points in the following two questions which I answered and you ignored my comments:
https://www.experts-exchange.com/questions/21158761/I-cannot-get-my-binary-search-tree-to-grow-when-i-call-my-insert-method.html
https://www.experts-exchange.com/questions/21154430/can-someone-tell-me-why-i-can't-get-the-height-of-a-binary-search-treee.html
Could you also then award me points in the following two questions which I answered and you ignored my comments:
https://www.experts-exchange.com/questions/21158761/I-cannot-get-my-binary-search-tree-to-grow-when-i-call-my-insert-method.html
https://www.experts-exchange.com/questions/21154430/can-someone-tell-me-why-i-can't-get-the-height-of-a-binary-search-treee.html
http://javatechniques.com/public/java/docs/basics/faster-deep-copy.html