Author: skitching
Date: Tue Feb 8 18:42:39 2005
New Revision: 152979
URL: http://svn.apache.org/viewcvs?view=rev&rev=152979
Log:
Add methods putInstanceData and getInstanceData, used initially
by the reworked CreateObjectWithFactoryAction.
Modified:
jakarta/commons/proper/digester/branches/digester2/src/java/org/apache/commons/digester2/Context.java
Modified:
jakarta/commons/proper/digester/branches/digester2/src/java/org/apache/commons/digester2/Context.java
URL:
http://svn.apache.org/viewcvs/jakarta/commons/proper/digester/branches/digester2/src/java/org/apache/commons/digester2/Context.java?view=diff&r1=152978&r2=152979
==============================================================================
---
jakarta/commons/proper/digester/branches/digester2/src/java/org/apache/commons/digester2/Context.java
(original)
+++
jakarta/commons/proper/digester/branches/digester2/src/java/org/apache/commons/digester2/Context.java
Tue Feb 8 18:42:39 2005
@@ -18,7 +18,10 @@
package org.apache.commons.digester2;
import java.util.List;
+import java.util.Map;
import java.util.HashMap;
+import java.util.ArrayList;
+import java.util.Iterator;
import java.util.EmptyStackException;
import org.apache.commons.logging.Log;
@@ -40,6 +43,23 @@
public class Context {
// ---------------------------------------------------
+ // Local classes
+ // ---------------------------------------------------
+
+ /**
+ * See method [EMAIL PROTECTED] #putInstanceData}.
+ */
+ private static class InstanceItem {
+ public Object key;
+ public Map map;
+
+ public InstanceItem(Object key, Map map) {
+ this.key = key;
+ this.map = map;
+ }
+ }
+
+ // ---------------------------------------------------
// Instance Variables
// ---------------------------------------------------
@@ -95,6 +115,12 @@
private HashMap stacksByName = new HashMap();
/**
+ * Place where other objects can store any data they like during a parse.
+ * See method [EMAIL PROTECTED] #putInstanceData} for more information.
+ */
+ private List instanceData = new ArrayList();
+
+ /**
* The parameters stack being utilized by CallMethodAction and
* CallParamAction.
*/
@@ -493,5 +519,68 @@
public void pushParams(Object object) {
params.push(object);
+ }
+
+ // -----------------------------------------------
+ // Other public methods
+ // -----------------------------------------------
+
+ /**
+ * Place where an object (typically an Action) can store any data it likes
+ * during a parse. Usually the "named stacks" facility is the most
+ * appropriate location for action-related data, as using stacks allows
+ * Actions to be re-entrant. However in some cases a stack is not
+ * needed (eg when building a cache of Class objects used by an Action).
+ * If the data is specific to an action instance, then the action instance
+ * itself should be passed as the first parameter. If the data is used by
+ * all action instances of a specific class, then the action's Class object
+ * can be used as the first parameter.
+ *
+ * @param instance is a key to separate data related to this object from
+ * other data stored on this context object.
+ *
+ * @param category identifies the particular item of data being stored,
+ * so that an instance can store multiple data items.
+ *
+ * @param data is the object to be stored for later retrieval.
+ */
+ public void putInstanceData(Object instance, String category, Object data)
{
+ // Unfortunately, maps use equals to find a matching key rather than
+ // identity, so we can't use a standard Map to implement this. As the
+ // number of entries here is likely to be very small anyway, we will
+ // just use a list-of-maps, and iterate over the list to find the
+ // correct entry.
+ //
+ // Note that if we trusted System.identityHashCode to return a unique
+ // string for an instance, then we could use a map. However that method
+ // doesn't promise to return a unique string on all platforms.
+
+ for(Iterator i = instanceData.iterator(); i.hasNext(); ) {
+ InstanceItem item = (InstanceItem) i.next();
+ if (item.key == instance) {
+ item.map.put(category, data);
+ return;
+ }
+ }
+
+ // this instance has never stored data before
+ Map map = new HashMap();
+ map.put(category, data);
+ InstanceItem instanceItem = new InstanceItem(instance, map);
+ instanceData.add(instanceItem);
+ }
+
+ /**
+ * Retrieve a piece of data stored earlier via putInstanceData.
+ */
+ public Object getInstanceData(Object instance, String category) {
+ for(Iterator i = instanceData.iterator(); i.hasNext(); ) {
+ InstanceItem item = (InstanceItem) i.next();
+ if (item.key == instance) {
+ return item.map.get(category);
+ }
+ }
+
+ return null;
}
}
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