Fix some issues from last commit

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/adapter/AbstractMethodInvokingDelegator.java

@@ -207,7 +207,7 @@ public abstract class AbstractMethodInvokingDelegator<T> implements Initializing
 	 * is assumed correct values will be supplied at runtime.
 	 */
 	public void setArguments(Object[] arguments) {
-		this.arguments = Arrays.asList(arguments).toArray();
+		this.arguments = arguments == null ? null : Arrays.asList(arguments).toArray();
 	}
 
 	/**

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/MultiResourceItemReader.java

@@ -204,6 +204,7 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
 	 * @param resources input resources
 	 */
 	public void setResources(Resource[] resources) {
+		Assert.notNull(resources, "The resources must not be null");
 		this.resources = Arrays.asList(resources).toArray(new Resource[resources.length]);
 	}
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/transform/AbstractLineTokenizer.java

@@ -79,7 +79,7 @@ public abstract class AbstractLineTokenizer implements LineTokenizer {
 	 * @param names
 	 */
 	public void setNames(String[] names) {
-		this.names = Arrays.asList(names).toArray(new String[names.length]);
+		this.names = names==null ? null : Arrays.asList(names).toArray(new String[names.length]);
 	}
 
 	/**

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/transform/BeanWrapperFieldExtractor.java

@@ -41,6 +41,7 @@ public class BeanWrapperFieldExtractor<T> implements FieldExtractor<T>, Initiali
 	 * @param names field names to be extracted by the {@link #extract(Object)} method.
 	 */
 	public void setNames(String[] names) {
+		Assert.notNull(names, "Names must be non-null");
 		this.names = Arrays.asList(names).toArray(new String[names.length]);
 	}