SPR-8015

+ update default key generator strategy to improve compatibility for implicit declaration on one arg method
+ updated docs

org.springframework.context/src/main/java/org/springframework/cache/KeyGenerator.java

@@ -20,7 +20,7 @@ import java.lang.reflect.Method;
 
 /**
  * Cache 'key' extractor. Used for creating a key based on the given method
- * (used as context) and its parameter.
+ * (used as context) and its parameters.
  * 
  * @author Costin Leau
  */

org.springframework.context/src/main/java/org/springframework/cache/support/DefaultKeyGenerator.java

@@ -21,14 +21,22 @@ import java.lang.reflect.Method;
 import org.springframework.cache.KeyGenerator;
 
 /**
- * Default key generator. Computes a resulting key based on the hashcode of the
- * given parameters.
+ * Default key generator. Returns 0 if no param is given, the param itself if only one is given or a hash code computed
+ * from all given params hash code.
  * 
  * @author Costin Leau
  */
 public class DefaultKeyGenerator implements KeyGenerator<Object> {
 
 	public Object extract(Method method, Object... params) {
+		if (params.length == 1) {
+			return params[0];
+		}
+
+		if (params.length == 0) {
+			return 0;
+		}
+
 		int hashCode = 17;
 
 		for (Object object : params) {

org.springframework.context/src/test/java/org/springframework/cache/config/AbstractAnnotationTest.java

@@ -77,6 +77,21 @@ public abstract class AbstractAnnotationTest {
 		assertSame(r3, r4);
 	}
 
+	public void testInvalidateWKey(CacheableService service) throws Exception {
+		Object o1 = new Object();
+		Object o2 = new Object();
+
+		Object r1 = service.cache(o1);
+		Object r2 = service.cache(o1);
+
+		assertSame(r1, r2);
+		service.invalidate(o1, null);
+		Object r3 = service.cache(o1);
+		Object r4 = service.cache(o1);
+		assertNotSame(r1, r3);
+		assertSame(r3, r4);
+	}
+
 	public void testConditionalExpression(CacheableService service)
 			throws Exception {
 		Object r1 = service.conditional(4);
@@ -132,6 +147,11 @@ public abstract class AbstractAnnotationTest {
 		testInvalidate(cs);
 	}
 
+	@Test
+	public void testInvalidateWithKey() throws Exception {
+		testInvalidateWKey(cs);
+	}
+
 	@Test
 	public void testConditionalExpression() throws Exception {
 		testConditionalExpression(cs);
@@ -152,6 +172,11 @@ public abstract class AbstractAnnotationTest {
 		testInvalidate(ccs);
 	}
 
+	@Test
+	public void testClassCacheInvalidateWKey() throws Exception {
+		testInvalidateWKey(ccs);
+	}
+
 	@Test
 	public void testNullValue() throws Exception {
 		testNullValue(cs);

org.springframework.context/src/test/java/org/springframework/cache/config/AnnotatedClassCacheableService.java

@@ -42,6 +42,10 @@ public class AnnotatedClassCacheableService implements CacheableService {
 	public void invalidate(Object arg1) {
 	}
 
+	@CacheEvict(value = "default", key = "#p0")
+	public void invalidate(Object arg1, Object arg2) {
+	}
+
 	@Cacheable(value = "default", key = "#p0")
 	public Object key(Object arg1, Object arg2) {
 		return counter.getAndIncrement();

org.springframework.context/src/test/java/org/springframework/cache/config/CacheableService.java

@@ -28,6 +28,8 @@ public interface CacheableService<T> {
 
 	void invalidate(Object arg1);
 
+	void invalidate(Object arg1, Object arg2);
+
 	T conditional(int field);
 
 	T key(Object arg1, Object arg2);

org.springframework.context/src/test/java/org/springframework/cache/config/DefaultCacheableService.java

@@ -40,6 +40,10 @@ public class DefaultCacheableService implements CacheableService<Long> {
 	public void invalidate(Object arg1) {
 	}
 
+	@CacheEvict(value = "default", key = "#p0")
+	public void invalidate(Object arg1, Object arg2) {
+	}
+
 	@Cacheable(value = "default", condition = "#classField == 3")
 	public Long conditional(int classField) {
 		return counter.getAndIncrement();