From b1f2eac2b998af7d392d05ad89c011d2e119f790 Mon Sep 17 00:00:00 2001
From: Oliver Gierke <info@olivergierke.de>
Date: Thu, 2 Feb 2012 14:50:01 +0100
Subject: [PATCH] DATACMNS-128 - Introduced
 ParameterAccessor.hasBindableNullValue().

---
 .../repository/query/ParameterAccessor.java   |  7 ++++
 .../query/ParametersParameterAccessor.java    | 24 +++++++++++
 .../ParametersParameterAccessorUnitTests.java | 40 ++++++++++++++-----
 3 files changed, 62 insertions(+), 9 deletions(-)

diff --git a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParameterAccessor.java b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParameterAccessor.java
index fd25a2adc..ecdfa33ab 100644
--- a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParameterAccessor.java
+++ b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParameterAccessor.java
@@ -52,6 +52,13 @@ public interface ParameterAccessor extends Iterable<Object> {
 	 */
 	Object getBindableValue(int index);
 
+	/**
+	 * Returns whether one of the bindable parameter values is {@literal null}.
+	 * 
+	 * @return
+	 */
+	boolean hasBindableNullValue();
+
 	/**
 	 * Returns an iterator over all <em>bindable</em> parameters. This means parameters implementing {@link Pageable} or
 	 * {@link Sort} will not be included in this {@link Iterator}.
diff --git a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java
index 945529081..58ab19d33 100644
--- a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java
+++ b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java
@@ -48,6 +48,15 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		this.values = values.clone();
 	}
 
+	/**
+	 * Returns the {@link Parameters} instance backing the accessor.
+	 * 
+	 * @return the parameters will never be {@literal null}.
+	 */
+	public Parameters getParameters() {
+		return parameters;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#getPageable()
@@ -98,6 +107,21 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		return values[parameters.getBindableParameter(index).getIndex()];
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.query.ParameterAccessor#hasBindableNullValue()
+	 */
+	public boolean hasBindableNullValue() {
+
+		for (Parameter parameter : parameters.getBindableParameters()) {
+			if (values[parameter.getIndex()] == null) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#iterator()
diff --git a/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/ParametersParameterAccessorUnitTests.java b/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/ParametersParameterAccessorUnitTests.java
index 190e4d670..a874c5879 100644
--- a/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/ParametersParameterAccessorUnitTests.java
+++ b/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/ParametersParameterAccessorUnitTests.java
@@ -18,24 +18,32 @@ package org.springframework.data.repository.query;
 import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
+import java.lang.reflect.Method;
 import java.util.Iterator;
 
+import org.junit.Before;
 import org.junit.Test;
+import org.springframework.data.domain.Pageable;
 
 /**
  * Unit tests for {@link ParametersParameterAccessor}.
- *
+ * 
  * @author Oliver Gierke
  */
 public class ParametersParameterAccessorUnitTests {
 
-	
+	Parameters parameters;
+
+	@Before
+	public void setUp() throws Exception {
+		parameters = new Parameters(Sample.class.getMethod("method", String.class, int.class));
+	}
+
 	@Test
 	public void accessorIteratorHasNext() throws SecurityException, NoSuchMethodException {
-		
-		Parameters parameters = new Parameters(Sample.class.getMethod("method", String.class, int.class));
-		ParameterAccessor accessor = new ParametersParameterAccessor(parameters, new Object[] { "Foo", 2});
-		
+
+		ParameterAccessor accessor = new ParametersParameterAccessor(parameters, new Object[] { "Foo", 2 });
+
 		Iterator<Object> iterator = accessor.iterator();
 		assertThat(iterator.hasNext(), is(true));
 		assertThat(iterator.next(), is((Object) "Foo"));
@@ -43,10 +51,24 @@ public class ParametersParameterAccessorUnitTests {
 		assertThat(iterator.next(), is((Object) 2));
 		assertThat(iterator.hasNext(), is(false));
 	}
-	
-	
+
+	@Test
+	public void detectsNullValue() throws Exception {
+
+		ParameterAccessor accessor = new ParametersParameterAccessor(parameters, new Object[] { null, 5 });
+		assertThat(accessor.hasBindableNullValue(), is(true));
+
+		Method method = Sample.class.getMethod("method", Pageable.class, String.class);
+		Parameters parameters = new Parameters(method);
+
+		accessor = new ParametersParameterAccessor(parameters, new Object[] { null, "Foo" });
+		assertThat(accessor.hasBindableNullValue(), is(false));
+	}
+
 	interface Sample {
-		
+
 		void method(String string, int integer);
+
+		void method(Pageable pageable, String string);
 	}
 }