RESOLVED - issue SWF-343: MapAccessor does not correctly handle null values

http://opensource.atlassian.com/projects/spring/browse/SWF-343

spring-binding/src/main/java/org/springframework/binding/collection/MapAccessor.java

@@ -48,6 +48,15 @@ public class MapAccessor implements MapAdaptable {
 		return map;
 	}
 
+	/**
+	 * Returns a value in the map, returning null if the attribute is not present.
+	 * @param key the key
+	 * @return the value
+	 */
+	public Object get(Object key) {
+		return map.get(key);
+	}
+
 	/**
 	 * Returns a value in the map, returning the defaultValue if no value was found.
 	 * @param key the key
@@ -390,7 +399,7 @@ public class MapAccessor implements MapAdaptable {
 	}
 
 	/**
-	 * Assert that value of the mak key is of the required type.
+	 * Assert that value of the map key, if non-null, is of the required type.
 	 * @param key the attribute name
 	 * @param requiredType the required attribute value type
 	 * @return the attribute value
@@ -400,7 +409,7 @@ public class MapAccessor implements MapAdaptable {
 	}
 
 	/**
-	 * Assert that the key value is an instance of the required type.
+	 * Assert that the key value, if non null, is an instance of the required type.
 	 * @param key the key
 	 * @param value the value
 	 * @param requiredType the required type
@@ -408,10 +417,10 @@ public class MapAccessor implements MapAdaptable {
 	 */
 	public Object assertKeyValueInstanceOf(Object key, Object value, Class requiredType) {
 		Assert.notNull(requiredType, "The required type to assert is required");
-		if (!requiredType.isInstance(value)) {
+		if (value != null && !requiredType.isInstance(value)) {
 			throw new IllegalArgumentException("Map key '" + key + "' has value [" + value
 					+ "] that is not of expected type [" + requiredType + "], instead it is of type ["
-					+ (value != null ? value.getClass().getName() : "null") + "]");
+					+ value.getClass().getName() + "]");
 		}
 		return value;
 	}

spring-binding/src/test/java/org/springframework/binding/collection/MapAccessorTests.java

@@ -0,0 +1,48 @@
+package org.springframework.binding.collection;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import junit.framework.TestCase;
+
+public class MapAccessorTests extends TestCase {
+	private MapAccessor accessor;
+
+	protected void setUp() throws Exception {
+		Map map = new HashMap();
+		map.put("string", "hello");
+		map.put("integer", new Integer(9));
+		map.put("null", null);
+		this.accessor = new MapAccessor(map);
+	}
+
+	public void testAccessNullAttribute() {
+		assertEquals(null, accessor.get("null"));
+		assertEquals(null, accessor.get("null", "something else"));
+		assertEquals(null, accessor.getRequired("null"));
+		assertEquals(null, accessor.getString("null"));
+		assertEquals(null, accessor.getRequiredString("null"));
+		assertEquals(null, accessor.getInteger("null"));
+		assertEquals(null, accessor.getRequiredInteger("null"));
+		assertEquals(null, accessor.getCollection("null"));
+		assertEquals(null, accessor.getRequiredCollection("null"));
+	}
+
+	public void testGetString() {
+		assertEquals("hello", accessor.getString("string"));
+		assertEquals("hello", accessor.getRequiredString("string"));
+	}
+
+	public void testGetInteger() {
+		assertEquals(new Integer(9), accessor.getInteger("integer"));
+		assertEquals(new Integer(9), accessor.getRequiredInteger("integer"));
+	}
+
+	public void testGetRequiredMissingKey() {
+		try {
+			accessor.getRequired("bogus");
+		} catch (IllegalArgumentException e) {
+		}
+	}
+
+}

spring-webflow/changelog.txt

@@ -5,6 +5,9 @@ http://www.springframework.org/webflow
 Changes in version 1.0.5 (21.08.2007)
 -------------------------------------
 
+Package org.springframework.webflow.binding
+* Fixed bug in MapAccessor where accessing a map entry with a null value would result in an exception (SWF-343).
+
 Package org.springframework.webflow.engine
 * Ensured the RequestContext attribute map can never be null (SWF-347).