[LMS-486] add: - 'AnnotationUtils.getAnnotatedParameters' and its test.

SVN: 7188

common/source/java/ch/systemsx/cisd/common/utilities/AnnotationUtils.java

@@ -116,4 +116,87 @@ public final class AnnotationUtils
         }
         return list;
     }
+
+    /**
+     * From the list of given annotations tries to return the one of given type.
+     * 
+     * @return <code>null</code> if not found.
+     */
+    public final static <A extends Annotation> A tryGetAnnotation(final Annotation[] annotations,
+            final Class<A> annotationType)
+    {
+        assert annotations != null : "Unspecified annotations";
+        assert annotationType != null : "Unspecified annotation type";
+        for (final Annotation annotation : annotations)
+        {
+            if (annotation.annotationType().equals(annotationType))
+            {
+                return annotationType.cast(annotation);
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns a list of method parameters where given <var>annotation</var> could be found.
+     * 
+     * @return never <code>null</code> but could return an empty list.
+     */
+    public final static <A extends Annotation> List<Parameter<A>> getAnnotatedParameters(
+            final Method method, final Class<A> annotationType)
+    {
+        assert method != null : "Unspecified method";
+        assert annotationType != null : "Unspecified annotation type";
+        final Annotation[][] annotations = method.getParameterAnnotations();
+        final Class<?>[] types = method.getParameterTypes();
+        final List<Parameter<A>> list = new ArrayList<Parameter<A>>();
+        for (int i = 0; i < types.length; i++)
+        {
+            final Class<?> type = types[i];
+            final A annotationOrNull = tryGetAnnotation(annotations[i], annotationType);
+            if (annotationOrNull != null)
+            {
+                list.add(new Parameter<A>(i, type, annotationOrNull));
+            }
+        }
+        return list;
+    }
+
+    //
+    // Helper classes
+    //
+
+    public final static class Parameter<A extends Annotation>
+    {
+        /**
+         * This parameter index in the list of method arguments.
+         */
+        private final int index;
+
+        private final Class<?> type;
+
+        private final A annotation;
+
+        Parameter(final int index, final Class<?> type, final A annotation)
+        {
+            this.index = index;
+            this.type = type;
+            this.annotation = annotation;
+        }
+
+        public final int getIndex()
+        {
+            return index;
+        }
+
+        public final Class<?> getType()
+        {
+            return type;
+        }
+
+        public final A getAnnotation()
+        {
+            return annotation;
+        }
+    }
 }

common/sourceTest/java/ch/systemsx/cisd/common/utilities/AnnotationUtilsTest.java

@@ -17,6 +17,7 @@
 package ch.systemsx.cisd.common.utilities;
 
 import static org.testng.AssertJUnit.assertEquals;
+import static org.testng.AssertJUnit.assertFalse;
 import static org.testng.AssertJUnit.fail;
 
 import java.lang.reflect.Field;
@@ -26,6 +27,7 @@ import java.util.List;
 import org.testng.annotations.Test;
 
 import ch.systemsx.cisd.common.annotation.BeanProperty;
+import ch.systemsx.cisd.common.utilities.AnnotationUtils.Parameter;
 
 /**
  * Test cases for the {@link AnnotationUtils} class.
@@ -35,6 +37,20 @@ import ch.systemsx.cisd.common.annotation.BeanProperty;
 public final class AnnotationUtilsTest
 {
 
+    private final static Method getDoSomethingMethod()
+    {
+        final Method[] methods = A.class.getDeclaredMethods();
+        for (final Method method : methods)
+        {
+            if (method.getName().equals("doSomething"))
+            {
+                return method;
+            }
+        }
+        fail();
+        return null;
+    }
+
     @Test
     public final void testGetAnnotatedFieldList()
     {
@@ -55,14 +71,15 @@ public final class AnnotationUtilsTest
     @Test
     public final void testGetAnnotatedMethodList()
     {
+        boolean fail = true;
         try
         {
             AnnotationUtils.getAnnotatedMethodList(null, null);
-            fail("Null value not accepted.");
         } catch (final AssertionError e)
         {
-            // Nothing to do here.
+            fail = false;
         }
+        assertFalse(fail);
         List<Method> methods = AnnotationUtils.getAnnotatedMethodList(A.class, BeanProperty.class);
         assertEquals(1, methods.size());
         methods = AnnotationUtils.getAnnotatedMethodList(B.class, BeanProperty.class);
@@ -73,6 +90,31 @@ public final class AnnotationUtilsTest
         }
     }
 
+    @SuppressWarnings("unchecked")
+    @Test
+    public final void testGetAnnotatedParameters()
+    {
+        boolean fail = true;
+        try
+        {
+            AnnotationUtils.getAnnotatedParameters(null, null);
+        } catch (final AssertionError e)
+        {
+            fail = false;
+        }
+        assertFalse(fail);
+        final Method method = getDoSomethingMethod();
+        List<?> annotatedParameters =
+                AnnotationUtils.getAnnotatedParameters(method, BeanProperty.class);
+        assertEquals(0, annotatedParameters.size());
+        annotatedParameters = AnnotationUtils.getAnnotatedParameters(method, Deprecated.class);
+        assertEquals(1, annotatedParameters.size());
+        final Parameter<Deprecated> parameter = (Parameter<Deprecated>) annotatedParameters.get(0);
+        assertEquals(Deprecated.class, parameter.getAnnotation().annotationType());
+        assertEquals(Object.class, parameter.getType());
+        assertEquals(2, parameter.getIndex());
+    }
+
     //
     // Helper classes
     //
@@ -91,6 +133,10 @@ public final class AnnotationUtilsTest
             this.a = a;
         }
 
+        void doSomething(final Object c, final String d, @Deprecated
+        final Object e)
+        {
+        }
     }
 
     private final static class B extends A
@@ -110,4 +156,4 @@ public final class AnnotationUtilsTest
             this.a = a;
         }
     }
-}
+}
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