(Richard Jones)

- SF Patch #1659837 ItemIterator now deals with item ids also


git-svn-id: http://scm.dspace.org/svn/repo/trunk@1756 9c30dcfa-912a-0410-8fc2-9e0234be79fd

dspace/CHANGES

@@ -1,5 +1,8 @@
 1.4.2 beta
 ===========
+(Richard Jones)
+- SF Patch #1659837 ItemIterator now deals with item ids also
+
 (Andrea Bollini)
 - SF Patch #1528142 Malformed OAI-PMH response: illegal bytes in UTF-8 for SF Bug #1490162
 
@@ -646,4 +649,4 @@ Bug fix for bug causing corruption of metadata if edited post-submission
 - Which metadata fields are indexed by lucene is now configurable.
 
 (Dave Stuve)
-- Oracle compatibility added
+- Oracle compatibility added

dspace/src/org/dspace/content/ItemIterator.java

@@ -41,6 +41,9 @@ package org.dspace.content;
 
 import java.sql.SQLException;
 
+import java.util.Iterator;
+import java.util.ArrayList;
+
 import org.dspace.core.Context;
 import org.dspace.storage.rdbms.TableRow;
 import org.dspace.storage.rdbms.TableRowIterator;
@@ -50,8 +53,12 @@ import org.dspace.storage.rdbms.TableRowIterator;
  * items into memory one by one, since in many cases, it would not make sense to
  * load a set of items into memory all at once. For example, loading in an
  * entire community or site's worth of items wouldn't make sense.
+ *
+ * Note that this class is not a real Iterator, as it does not implement
+ * the Iterator interface
  * 
  * @author Robert Tansley
+ * @author Richard Jones
  * @version $Revision$
  */
 public class ItemIterator
@@ -66,29 +73,55 @@ public class ItemIterator
     /** The table row iterator of Item rows */
     private TableRowIterator itemRows;
 
+    /** a real iterator which works over the item ids when present */
+    private Iterator iditr;
+    
     /**
-     * Construct an item iterator. This is not a public method, since this
-     * iterator is only created by CM API methods.
+     * Construct an item iterator using a set of TableRow objects from
+     * the item table
      * 
      * @param context
      *            our context
      * @param rows
      *            the rows that correspond to the Items to be iterated over
      */
-    ItemIterator(Context context, TableRowIterator rows)
+    public ItemIterator(Context context, TableRowIterator rows)
     {
         ourContext = context;
         itemRows = rows;
     }
 
+    /**
+     * Construct an item iterator using an array list of item ids
+     * 
+     * @param context
+     *            our context
+     * @param iids
+     *            the array list to be iterated over
+     */
+    public ItemIterator(Context context, ArrayList iids)
+    {
+    	ourContext = context;
+    	iditr = iids.iterator();
+    }
+    
     /**
      * Find out if there are any more items to iterate over
      * 
      * @return <code>true</code> if there are more items
+     * @throws SQLException
      */
     public boolean hasNext() throws SQLException
     {
-        return itemRows.hasNext();
+    	if (iditr != null)
+    	{
+    		return iditr.hasNext();
+    	}
+    	else if (itemRows != null)
+    	{
+    		return itemRows.hasNext();
+    	}
+    	return false;
     }
 
     /**
@@ -96,10 +129,125 @@ public class ItemIterator
      * are no more items.
      * 
      * @return the next item, or <code>null</code>
+     * @throws SQLException
      */
     public Item next() throws SQLException
     {
-        if (itemRows.hasNext())
+    	if (iditr != null)
+    	{
+    		return nextByID();
+    	}
+    	else if (itemRows != null)
+    	{
+    		return nextByRow();
+    	}
+    	return null;
+    }
+    
+    /**
+     * This private method knows how to get the next result out of the 
+     * item id iterator
+     * 
+     * @return	the next item instantiated from the id
+     * @throws SQLException
+     */
+    private Item nextByID()
+    	throws SQLException
+    {
+    	if (iditr.hasNext())
+        {
+    		// get the id
+    		int id = ((Integer) iditr.next()).intValue();
+    		
+            // Check cache
+            Item fromCache = (Item) ourContext.fromCache(Item.class, id);
+
+            if (fromCache != null)
+            {
+                return fromCache;
+            }
+            else
+            {
+                return Item.find(ourContext, id);
+            }
+        }
+        else
+        {
+            return null;
+        }
+    }
+    
+    /**
+     * return the id of the next item.
+     * 
+     * @return	the next id or -1 if none
+     */
+    public int nextID()
+    	throws SQLException
+    {
+    	if (iditr != null)
+    	{
+    		return nextByIDID();
+    	}
+    	else if (itemRows != null)
+    	{
+    		return nextByRowID();
+    	}
+    	return -1;
+    }
+    
+    /**
+     * Sorry about the name of this one!  It returns the ID of the item
+     * as opposed to the item itself when we are iterating over an ArrayList
+     * of item ids
+     * 
+     * @return	the item id, or -1 if none
+     */
+    private int nextByIDID()
+    {
+    	if (iditr.hasNext())
+        {
+    		// get the id
+    		int id = ((Integer) iditr.next()).intValue();
+    		
+            return id;
+        }
+        else
+        {
+            return -1;
+        }
+    }
+    
+    /**
+     * Returns the ID of the item as opposed to the item itself when we are
+     * iterating over the TableRow array.
+     * 
+     * @return	the item id, or -1 if none
+     */
+    private int nextByRowID()
+    	throws SQLException
+    {
+    	if (itemRows.hasNext())
+        {
+            TableRow row = itemRows.next();
+            return row.getIntColumn("item_id");
+        }
+        else
+        {
+            return -1;
+        }
+    }
+    
+    /**
+     * Return the next item instantiated from the supplied TableRow
+     * 
+     * @return	the item or null if none
+     * @throws SQLException
+     */
+    private Item nextByRow()
+    	throws SQLException
+    {
+    	if (itemRows.hasNext())
         {
             // Convert the row into an Item object
             TableRow row = itemRows.next();