Add @Nullable to ParametersParameterAccessor.getValue().

Add missing Override and Nullable annotations. Update Javadoc to mention correct return value.

Closes #2506

src/main/java/org/springframework/data/repository/query/ParameterAccessor.java

@@ -31,7 +31,7 @@ import org.springframework.lang.Nullable;
 public interface ParameterAccessor extends Iterable<Object> {
 
 	/**
-	 * Returns the {@link Pageable} of the parameters, if available. Returns {@code null} otherwise.
+	 * Returns the {@link Pageable} of the parameters, if available. Returns {@link Pageable#unpaged()} otherwise.
 	 *
 	 * @return
 	 */
@@ -39,7 +39,8 @@ public interface ParameterAccessor extends Iterable<Object> {
 
 	/**
 	 * Returns the sort instance to be used for query creation. Will use a {@link Sort} parameter if available or the
-	 * {@link Sort} contained in a {@link Pageable} if available. Returns {@code null} if no {@link Sort} can be found.
+	 * {@link Sort} contained in a {@link Pageable} if available. Returns {@link Sort#unsorted()} if no {@link Sort} can
+	 * be found.
 	 *
 	 * @return
 	 */
@@ -72,6 +73,7 @@ public interface ParameterAccessor extends Iterable<Object> {
 	 * @param index
 	 * @return
 	 */
+	@Nullable
 	Object getBindableValue(int index);
 
 	/**

src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java

@@ -96,6 +96,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#getPageable()
 	 */
+	@Override
 	public Pageable getPageable() {
 
 		if (!parameters.hasPageableParameter()) {
@@ -111,6 +112,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#getSort()
 	 */
+	@Override
 	public Sort getSort() {
 
 		if (parameters.hasSortParameter()) {
@@ -158,6 +160,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * @return
 	 */
 	@SuppressWarnings("unchecked")
+	@Nullable
 	protected <T> T getValue(int index) {
 		return (T) values[index];
 	}
@@ -166,6 +169,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#getBindableValue(int)
 	 */
+	@Override
 	public Object getBindableValue(int index) {
 		return values[parameters.getBindableParameter(index).getIndex()];
 	}
@@ -174,6 +178,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#hasBindableNullValue()
 	 */
+	@Override
 	public boolean hasBindableNullValue() {
 
 		for (Parameter parameter : parameters.getBindableParameters()) {
@@ -189,6 +194,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.ParameterAccessor#iterator()
 	 */
+	@Override
 	public BindableParameterIterator iterator() {
 		return new BindableParameterIterator(this);
 	}
@@ -223,6 +229,8 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		 *
 		 * @return
 		 */
+		@Nullable
+		@Override
 		public Object next() {
 			return accessor.getBindableValue(currentIndex++);
 		}
@@ -231,6 +239,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		 * (non-Javadoc)
 		 * @see java.util.Iterator#hasNext()
 		 */
+		@Override
 		public boolean hasNext() {
 			return bindableParameterCount > currentIndex;
 		}
@@ -239,6 +248,7 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		 * (non-Javadoc)
 		 * @see java.util.Iterator#remove()
 		 */
+		@Override
 		public void remove() {
 			throw new UnsupportedOperationException();
 		}