Author: oheger
Date: Wed Nov 5 23:23:41 2008
New Revision: 711782
URL: http://svn.apache.org/viewvc?rev=711782&view=rev
Log:
CONFIGURATION-347: The Iterator returned by AbstractConfiguration.getKeys() now
points to a snapshot of the keys. This prevents
ConcurrentModificationExceptions during iteration when a reload happens.
Modified:
commons/proper/configuration/trunk/src/java/org/apache/commons/configuration/AbstractFileConfiguration.java
commons/proper/configuration/trunk/src/test/org/apache/commons/configuration/TestFileConfiguration.java
commons/proper/configuration/trunk/xdocs/changes.xml
Modified:
commons/proper/configuration/trunk/src/java/org/apache/commons/configuration/AbstractFileConfiguration.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/java/org/apache/commons/configuration/AbstractFileConfiguration.java?rev=711782&r1=711781&r2=711782&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/java/org/apache/commons/configuration/AbstractFileConfiguration.java
(original)
+++
commons/proper/configuration/trunk/src/java/org/apache/commons/configuration/AbstractFileConfiguration.java
Wed Nov 5 23:23:41 2008
@@ -32,6 +32,8 @@
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
import org.apache.commons.configuration.reloading.InvariantReloadingStrategy;
import org.apache.commons.configuration.reloading.ReloadingStrategy;
@@ -40,7 +42,7 @@
/**
* <p>Partial implementation of the <code>FileConfiguration</code> interface.
- * Developpers of file based configuration may want to extend this class,
+ * Developers of file based configuration may want to extend this class,
* the two methods left to implement are <code>[EMAIL PROTECTED]
FileConfiguration#load(Reader)}</code>
* and <code>[EMAIL PROTECTED] FileConfiguration#save(Writer)}</code>.</p>
* <p>This base class already implements a couple of ways to specify the
location
@@ -934,10 +936,39 @@
return super.containsKey(key);
}
+ /**
+ * Returns an <code>Iterator</code> with the keys contained in this
+ * configuration. This implementation performs a reload if necessary before
+ * obtaining the keys. The <code>Iterator</code> returned by this method
+ * points to a snapshot taken when this method was called. Later changes at
+ * the set of keys (including those caused by a reload) won't be visible.
+ * This is because a reload can happen at any time during iteration, and it
+ * is impossible to determine how this reload affects the current
iteration.
+ * When using the iterator a client has to be aware that changes of the
+ * configuration are possible at any time. For instance, if after a reload
+ * operation some keys are no longer present, the iterator will still
return
+ * those keys because they were found when it was created.
+ *
+ * @return an <code>Iterator</code> with the keys of this configuration
+ */
public Iterator getKeys()
{
reload();
- return super.getKeys();
+ List keyList = new LinkedList();
+ enterNoReload();
+ try
+ {
+ for (Iterator it = super.getKeys(); it.hasNext();)
+ {
+ keyList.add(it.next());
+ }
+
+ return keyList.iterator();
+ }
+ finally
+ {
+ exitNoReload();
+ }
}
/**
Modified:
commons/proper/configuration/trunk/src/test/org/apache/commons/configuration/TestFileConfiguration.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/test/org/apache/commons/configuration/TestFileConfiguration.java?rev=711782&r1=711781&r2=711782&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/test/org/apache/commons/configuration/TestFileConfiguration.java
(original)
+++
commons/proper/configuration/trunk/src/test/org/apache/commons/configuration/TestFileConfiguration.java
Wed Nov 5 23:23:41 2008
@@ -17,20 +17,21 @@
package org.apache.commons.configuration;
-import java.net.URL;
-import java.util.Properties;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
+import java.net.URL;
+import java.util.Iterator;
+import java.util.Properties;
+
+import junit.framework.TestCase;
import org.apache.commons.configuration.reloading.FileAlwaysReloadingStrategy;
import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy;
-import junit.framework.TestCase;
-
/**
* @author Emmanuel Bourg
* @version $Revision$, $Date$
@@ -426,7 +427,7 @@
}
/**
- * Tests to invoke save() without explicitely setting a file name. This
+ * Tests to invoke save() without explicitly setting a file name. This
* will cause an exception.
*/
public void testSaveWithoutFileName() throws Exception
@@ -590,6 +591,44 @@
}
/**
+ * Tests iterating over the keys of a non hierarchical file-based
+ * configuration while a reload happens. This test is related to
+ * CONFIGURATION-347.
+ */
+ public void testIterationWithReloadFlat() throws ConfigurationException
+ {
+ PropertiesConfiguration config = new
PropertiesConfiguration(TEST_FILE);
+ checkIterationWithReload(config);
+ }
+
+ /**
+ * Tests iterating over the keys of a hierarchical file-based configuration
+ * while a reload happens. This test is related to CONFIGURATION-347.
+ */
+ public void testIterationWithReloadHierarchical()
+ throws ConfigurationException
+ {
+ XMLConfiguration config = new XMLConfiguration("test.xml");
+ checkIterationWithReload(config);
+ }
+
+ /**
+ * Helper method for testing an iteration over the keys of a file-based
+ * configuration while a reload happens.
+ *
+ * @param config the configuration to test
+ */
+ private void checkIterationWithReload(FileConfiguration config)
+ {
+ config.setReloadingStrategy(new FileAlwaysReloadingStrategy());
+ for (Iterator it = config.getKeys(); it.hasNext();)
+ {
+ String key = (String) it.next();
+ assertNotNull("No value for key " + key, config.getProperty(key));
+ }
+ }
+
+ /**
* Helper method for comparing the content of two configuration objects.
*
* @param config1 the first configuration
Modified: commons/proper/configuration/trunk/xdocs/changes.xml
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/xdocs/changes.xml?rev=711782&r1=711781&r2=711782&view=diff
==============================================================================
--- commons/proper/configuration/trunk/xdocs/changes.xml (original)
+++ commons/proper/configuration/trunk/xdocs/changes.xml Wed Nov 5 23:23:41
2008
@@ -23,6 +23,12 @@
<body>
<release version="1.6" date="in SVN" description="">
+ <action dev="oheger" type="fix" issue="CONFIGURATION-347">
+ AbstractFileConfiguration.getKeys() now returns an iterator that points
+ to a snapshot of the keys of the configuration. This prevents
+ ConcurrentModificationExceptions during iteration when a reload is
+ performed.
+ </action>
<action dev="oheger" type="fix" issue="CONFIGURATION-346">
ConfigurationUtils.convertToHierarchical() now creates multiple
configuration nodes for properties with multiple values. This
