Author: oheger
Date: Thu Aug 22 20:01:24 2013
New Revision: 1516578
URL: http://svn.apache.org/r1516578
Log:
Added a special handling for empty elements.
When converting to a list or to an array it makes sense to handle empty
elements in a configuration in a special way - rather than returning a
collection with a single empty element, an empty collection should be
returned. This is now implemented by DefaultConversionHandler. A new method was
added which determines whether an element is empty. So this can be customized
by subclasses.
Modified:
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/convert/DefaultConversionHandler.java
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/convert/TestDefaultConversionHandler.java
Modified:
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/convert/DefaultConversionHandler.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/convert/DefaultConversionHandler.java?rev=1516578&r1=1516577&r2=1516578&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/convert/DefaultConversionHandler.java
(original)
+++
commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/convert/DefaultConversionHandler.java
Thu Aug 22 20:01:24 2013
@@ -128,6 +128,10 @@ public class DefaultConversionHandler im
{
return null;
}
+ if (isEmptyElement(src))
+ {
+ return Array.newInstance(elemClass, 0);
+ }
ConfigurationInterpolator interpolator = fetchInterpolator(ci);
return elemClass.isPrimitive() ? toPrimitiveArray(src, elemClass,
@@ -151,7 +155,7 @@ public class DefaultConversionHandler im
"Target collection must not be null!");
}
- if (src != null)
+ if (src != null && !isEmptyElement(src))
{
ConfigurationInterpolator interpolator = fetchInterpolator(ci);
convertToCollection(src, elemClass, interpolator, dest);
@@ -181,6 +185,23 @@ public class DefaultConversionHandler im
}
/**
+ * Tests whether the passed in object represents an empty element. This
+ * method is called by conversion methods to arrays or collections. If it
+ * returns <b>true</b>, the resulting array or collection will be empty.
+ * This implementation returns <b>true</b> if and only if the passed in
+ * object is an empty string. With this method it can be controlled if and
+ * how empty elements in configurations are handled.
+ *
+ * @param src the object to be tested
+ * @return a flag whether this object is an empty element
+ */
+ protected boolean isEmptyElement(Object src)
+ {
+ return (src instanceof CharSequence)
+ && ((CharSequence) src).length() == 0;
+ }
+
+ /**
* Performs the conversion from the passed in source object to the
specified
* target class. This method is called for each conversion to be done. The
* source object has already been passed to the
Modified:
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/convert/TestDefaultConversionHandler.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/convert/TestDefaultConversionHandler.java?rev=1516578&r1=1516577&r2=1516578&view=diff
==============================================================================
---
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/convert/TestDefaultConversionHandler.java
(original)
+++
commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/convert/TestDefaultConversionHandler.java
Thu Aug 22 20:01:24 2013
@@ -209,6 +209,18 @@ public class TestDefaultConversionHandle
}
/**
+ * Tests a conversion to a collection if an empty string is passed in. An
+ * empty string should be interpreted as a list with no values.
+ */
+ @Test
+ public void testToCollectionEmptyString()
+ {
+ List<Integer> col = new ArrayList<Integer>(1);
+ handler.toCollection("", Integer.class, null, col);
+ assertTrue("Got elements", col.isEmpty());
+ }
+
+ /**
* Tests toArray() if the source object is null.
*/
@Test
@@ -287,6 +299,17 @@ public class TestDefaultConversionHandle
}
/**
+ * Tests a conversion to an array from an empty string. An empty string
+ * should be interpreted as an empty array.
+ */
+ @Test
+ public void testToArrayEmptyString()
+ {
+ int[] array = (int[]) handler.toArray("", Integer.TYPE, null);
+ assertEquals("Got elements", 0, array.length);
+ }
+
+ /**
* Tests whether the default date format is used if no format has been set.
*/
@Test
