Author: oheger
Date: Tue Sep 9 17:56:29 2014
New Revision: 1623862
URL: http://svn.apache.org/r1623862
Log:
[CONFIGURATION-570] Alternative implementation of SystemConfiguration.getKeys().
In order to avoid ConcurrentModificationExceptions when iterating over the
keys of a SystemConfiguration, the iterator returned for the keys is now a
snapshot.
Modified:
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/SystemConfiguration.java
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/TestSystemConfiguration.java
Modified:
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/SystemConfiguration.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/SystemConfiguration.java?rev=1623862&r1=1623861&r2=1623862&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/SystemConfiguration.java
(original)
+++
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/SystemConfiguration.java
Tue Sep 9 17:56:29 2014
@@ -104,4 +104,14 @@ public class SystemConfiguration extends
System.setProperty(key, value);
}
}
+
+ /**
+ * {@inheritDoc} This implementation returns a snapshot of the keys in the
+ * system properties. If another thread modifies system properties
concurrently,
+ * these changes are not reflected by the iterator returned by this method.
+ */
+ @Override
+ protected Iterator<String> getKeysInternal() {
+ return System.getProperties().stringPropertyNames().iterator();
+ }
}
Modified:
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/TestSystemConfiguration.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/TestSystemConfiguration.java?rev=1623862&r1=1623861&r2=1623862&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/TestSystemConfiguration.java
(original)
+++
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/TestSystemConfiguration.java
Tue Sep 9 17:56:29 2014
@@ -22,7 +22,9 @@ import static org.junit.Assert.assertTru
import java.io.File;
import java.io.IOException;
+import java.util.Iterator;
import java.util.Properties;
+import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.commons.configuration.ex.ConfigurationException;
import org.apache.commons.configuration.io.FileHandler;
@@ -92,4 +94,61 @@ public class TestSystemConfiguration
assertEquals("System property not changed", "true",
System.getProperty(testProperty));
}
+
+ /**
+ * Tests an append operation with a system configuration while system
+ * properties are modified from another thread. This is related to
+ * CONFIGURATION-570.
+ */
+ @Test
+ public void testAppendWhileConcurrentAccess() throws InterruptedException
+ {
+ final AtomicBoolean stop = new AtomicBoolean();
+ final String property =
+ SystemConfiguration.class.getName() + ".testProperty";
+ Thread t = new Thread()
+ {
+ @Override
+ public void run()
+ {
+ boolean setValue = true;
+ while (!stop.get())
+ {
+ if (setValue)
+ {
+ System.setProperty(property, "true");
+ }
+ else
+ {
+ System.clearProperty(property);
+ }
+ setValue = !setValue;
+ }
+ }
+ };
+ try
+ {
+ t.start();
+
+ SystemConfiguration config = new SystemConfiguration();
+ PropertiesConfiguration props = new PropertiesConfiguration();
+ props.append(config);
+
+ stop.set(true);
+ t.join();
+ for (Iterator<String> keys = config.getKeys(); keys.hasNext();)
+ {
+ String key = keys.next();
+ if (!property.equals(key))
+ {
+ assertEquals("Wrong value for " + key,
+ config.getString(key), props.getString(key));
+ }
+ }
+ }
+ finally
+ {
+ System.clearProperty(property);
+ }
+ }
}
