BATCH-2761: Varargs in reader, processor, and writer builders

If a builder has a builder method that takes a List, it should also provide a builder method that takes a varargs.

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/builder/MongoItemReaderBuilder.java

@@ -16,6 +16,7 @@
 
 package org.springframework.batch.item.data.builder;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -31,6 +32,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Glenn Renfro
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  * @since 4.0
  * @see MongoItemReader
  */
@@ -41,7 +43,7 @@ public class MongoItemReaderBuilder<T> {
 
 	private Class<? extends T> targetType;
 
-	Map<String, Sort.Direction> sorts;
+	private Map<String, Sort.Direction> sorts;
 
 	private String hint;
 
@@ -175,6 +177,17 @@ public class MongoItemReaderBuilder<T> {
 		return this;
 	}
 
+	/**
+	 * Values to be substituted in for each of the parameters in the query.
+	 *
+	 * @param parameterValues values
+	 * @return The current instance of the builder
+	 * @see MongoItemReader#setParameterValues(List)
+	 */
+	public MongoItemReaderBuilder<T> parameterValues(Object... parameterValues) {
+		return parameterValues(Arrays.asList(parameterValues));
+	}
+
 	/**
 	 * JSON defining the fields to be returned from the matching documents by MongoDB.
 	 *

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/builder/RepositoryItemReaderBuilder.java

@@ -37,10 +37,10 @@ import org.springframework.util.StringUtils;
  *
  * @author Glenn Renfro
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  * @since 4.0
  * @see RepositoryItemReader
  */
-
 public class RepositoryItemReaderBuilder<T> {
 
 	private PagingAndSortingRepository<?, ?> repository;
@@ -131,6 +131,17 @@ public class RepositoryItemReaderBuilder<T> {
 		return this;
 	}
 
+	/**
+	 * Arguments to be passed to the data providing method.
+	 *
+	 * @param arguments the method arguments to be passed to the repository.
+	 * @return The current instance of the builder.
+	 * @see RepositoryItemReader#setArguments(List)
+	 */
+	public RepositoryItemReaderBuilder<T> arguments(Object... arguments) {
+		return arguments(Arrays.asList(arguments));
+	}
+
 	/**
 	 * Provides ordering of the results so that order is maintained between paged queries.
 	 *

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/builder/JdbcCursorItemReaderBuilder.java

@@ -35,6 +35,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Michael Minella
  * @author Glenn Renfro
+ * @author Drummond Dawson
  * @since 4.0
  */
 public class JdbcCursorItemReaderBuilder<T> {
@@ -246,7 +247,7 @@ public class JdbcCursorItemReaderBuilder<T> {
 	 * @param args values to set on the reader query
 	 * @return this instance for method chaining
 	 */
-	public JdbcCursorItemReaderBuilder<T> queryArguments(Object[] args) {
+	public JdbcCursorItemReaderBuilder<T> queryArguments(Object... args) {
 		this.preparedStatementSetter = new ArgumentPreparedStatementSetter(args);
 
 		return this;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/builder/StoredProcedureItemReaderBuilder.java

@@ -31,6 +31,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  * @since 4.0.0
  * @see StoredProcedureItemReader
  */
@@ -284,7 +285,7 @@ public class StoredProcedureItemReaderBuilder<T> {
 	 * @return this instance for method chaining
 	 * @see StoredProcedureItemReader#setParameters(SqlParameter[])
 	 */
-	public StoredProcedureItemReaderBuilder<T> parameters(SqlParameter[] parameters) {
+	public StoredProcedureItemReaderBuilder<T> parameters(SqlParameter... parameters) {
 		this.parameters = parameters;
 
 		return this;

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

@@ -54,6 +54,7 @@ import org.springframework.util.StringUtils;
  * @author Michael Minella
  * @author Glenn Renfro
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  * @since 4.0
  * @see FlatFileItemReader
  */
@@ -183,7 +184,7 @@ public class FlatFileItemReaderBuilder<T> {
 	 * @return The current instance of the builder.
 	 * @see FlatFileItemReader#setComments(String[])
 	 */
-	public FlatFileItemReaderBuilder<T> comments(String[] comments) {
+	public FlatFileItemReaderBuilder<T> comments(String... comments) {
 		this.comments.addAll(Arrays.asList(comments));
 		return this;
 	}
@@ -610,7 +611,7 @@ public class FlatFileItemReaderBuilder<T> {
 		 * @return The parent {@link FlatFileItemReaderBuilder}
 		 * @see DelimitedLineTokenizer#setNames(String[])
 		 */
-		public FlatFileItemReaderBuilder<T> names(String [] names) {
+		public FlatFileItemReaderBuilder<T> names(String... names) {
 			this.names.addAll(Arrays.asList(names));
 			return this.parent;
 		}
@@ -691,7 +692,7 @@ public class FlatFileItemReaderBuilder<T> {
 		 * @return This instance for chaining
 		 * @see FixedLengthTokenizer#setColumns(Range[])
 		 */
-		public FixedLengthBuilder<T> columns(Range[] ranges) {
+		public FixedLengthBuilder<T> columns(Range... ranges) {
 			this.ranges.addAll(Arrays.asList(ranges));
 			return this;
 		}
@@ -728,7 +729,7 @@ public class FlatFileItemReaderBuilder<T> {
 		 * @return The parent builder
 		 * @see FixedLengthTokenizer#setNames(String[])
 		 */
-		public FlatFileItemReaderBuilder<T> names(String [] names) {
+		public FlatFileItemReaderBuilder<T> names(String... names) {
 			this.names.addAll(Arrays.asList(names));
 			return this.parent;
 		}

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

@@ -38,6 +38,7 @@ import org.springframework.util.StringUtils;
  * @author Michael Minella
  * @author Glenn Renfro
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  * @since 4.0
  * @see FlatFileItemWriter
  */
@@ -364,7 +365,7 @@ public class FlatFileItemWriterBuilder<T> {
 		 * @return The parent {@link FlatFileItemWriterBuilder}
 		 * @see BeanWrapperFieldExtractor#setNames(String[])
 		 */
-		public FlatFileItemWriterBuilder<T> names(String[] names) {
+		public FlatFileItemWriterBuilder<T> names(String... names) {
 			this.names.addAll(Arrays.asList(names));
 			return this.parent;
 		}
@@ -438,7 +439,7 @@ public class FlatFileItemWriterBuilder<T> {
 		 * @return The parent {@link FlatFileItemWriterBuilder}
 		 * @see BeanWrapperFieldExtractor#setNames(String[])
 		 */
-		public FlatFileItemWriterBuilder<T> names(String[] names) {
+		public FlatFileItemWriterBuilder<T> names(String... names) {
 			this.names.addAll(Arrays.asList(names));
 			return this.parent;
 		}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -28,6 +28,7 @@ import org.springframework.util.StringUtils;
  * A builder implementation for the {@link MultiResourceItemReader}.
  *
  * @author Glenn Renfro
+ * @author Drummond Dawson
  * @since 4.0
  * @see MultiResourceItemReader
  */
@@ -83,7 +84,7 @@ public class MultiResourceItemReaderBuilder<T> {
 	 *
 	 * @see MultiResourceItemReader#setResources(Resource[])
 	 */
-	public MultiResourceItemReaderBuilder<T> resources(Resource[] resources) {
+	public MultiResourceItemReaderBuilder<T> resources(Resource... resources) {
 		this.resources = resources;
 
 		return this;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/builder/CompositeItemProcessorBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 
 package org.springframework.batch.item.support.builder;
 
+import java.util.Arrays;
 import java.util.List;
 
 import org.springframework.batch.item.ItemProcessor;
@@ -26,7 +27,7 @@ import org.springframework.util.Assert;
  * Creates a fully qualified {@link CompositeItemProcessorBuilder}.
  *
  * @author Glenn Renfro
- *
+ * @author Drummond Dawson
  * @since 4.0
  */
 public class CompositeItemProcessorBuilder<I, O> {
@@ -44,6 +45,16 @@ public class CompositeItemProcessorBuilder<I, O> {
 		return this;
 	}
 
+	/**
+	 * Establishes the {@link ItemProcessor} delegates that will work on the item to be processed.
+	 * @param delegates the {@link ItemProcessor} delegates that will work on the item.
+	 * @return this instance for method chaining.
+	 * @see CompositeItemProcessorBuilder#delegates(List)
+	 */
+	public CompositeItemProcessorBuilder<I, O> delegates(ItemProcessor<?, ?>... delegates) {
+		return delegates(Arrays.asList(delegates));
+	}
+
 	/**
 	 * Returns a fully constructed {@link CompositeItemProcessor}.
 	 *

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/builder/CompositeItemWriterBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 
 package org.springframework.batch.item.support.builder;
 
+import java.util.Arrays;
 import java.util.List;
 
 import org.springframework.batch.item.ItemWriter;
@@ -26,7 +27,7 @@ import org.springframework.util.Assert;
  * Creates a fully qualified CompositeItemWriter.
  *
  * @author Glenn Renfro
- *
+ * @author Drummond Dawson
  * @since 4.0
  */
 public class CompositeItemWriterBuilder<T> {
@@ -67,6 +68,20 @@ public class CompositeItemWriterBuilder<T> {
 		return this;
 	}
 
+	/**
+	 * The item writers to use as delegates. Items are written to each of the
+	 * delegates.
+	 *
+	 * @param delegates the delegates to use. The delegates list must not be null
+	 * nor be empty.
+	 * @return this instance for method chaining.
+	 *
+	 * @see CompositeItemWriter#setDelegates(List)
+	 */
+	public CompositeItemWriterBuilder<T> delegates(ItemWriter<? super T>... delegates) {
+		return delegates(Arrays.asList(delegates));
+	}
+
 	/**
 	 * Returns a fully constructed {@link CompositeItemWriter}.
 	 *

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/MongoItemReaderBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -40,6 +40,7 @@ import static org.mockito.Mockito.when;
 
 /**
  * @author Glenn Renfro
+ * @author Drummond Dawson
  */
 public class MongoItemReaderBuilderTests {
 	@Mock
@@ -123,6 +124,27 @@ public class MongoItemReaderBuilderTests {
 		assertEquals("collection", collectionContainer.getValue());
 	}
 
+	@Test
+	public void testVarargs() throws Exception {
+		MongoItemReader<String> reader = getBasicBuilder()
+				.parameterValues("foo")
+				.jsonQuery("{ name : ?0 }")
+				.collection("collection")
+				.build();
+
+		ArgumentCaptor<String> collectionContainer = ArgumentCaptor.forClass(String.class);
+
+		when(this.template.find(this.queryContainer.capture(), eq(String.class), collectionContainer.capture()))
+				.thenReturn(new ArrayList<>());
+
+		assertNull("reader should not return result", reader.read());
+
+		Query query = this.queryContainer.getValue();
+		assertEquals("{ \"name\" : \"foo\" }", query.getQueryObject().toJson());
+		assertEquals("{ \"name\" : -1 }", query.getSortObject().toJson());
+		assertEquals("collection", collectionContainer.getValue());
+	}
+
 	@Test
 	public void testNullTemplate() {
 		validateExceptionMessage(new MongoItemReaderBuilder<String>().targetType(String.class)

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/RepositoryItemReaderBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -40,6 +40,7 @@ import static org.mockito.Mockito.when;
 
 /**
  * @author Glenn Renfro
+ * @author Drummond Dawson
  */
 public class RepositoryItemReaderBuilderTests {
 
@@ -257,6 +258,26 @@ public class RepositoryItemReaderBuilderTests {
 		verifyMultiArgRead(arg1Captor, arg2Captor, arg3Captor, result);
 	}
 
+	@Test
+	public void testVarargArguments() throws Exception {
+		ArgumentCaptor<String> arg1Captor = ArgumentCaptor.forClass(String.class);
+		ArgumentCaptor<String> arg2Captor = ArgumentCaptor.forClass(String.class);
+		ArgumentCaptor<String> arg3Captor = ArgumentCaptor.forClass(String.class);
+		when(this.repository.foo(arg1Captor.capture(), arg2Captor.capture(), arg3Captor.capture(),
+				this.pageRequestContainer.capture())).thenReturn(this.page);
+
+		RepositoryItemReader<Object> reader = new RepositoryItemReaderBuilder<>().repository(this.repository)
+				.sorts(this.sorts)
+				.maxItemCount(5)
+				.methodName("foo")
+				.name("bar")
+				.arguments(ARG1, ARG2, ARG3)
+				.build();
+
+		String result = (String) reader.read();
+		verifyMultiArgRead(arg1Captor, arg2Captor, arg3Captor, result);
+	}
+
 	public interface TestRepository extends PagingAndSortingRepository<Object, Integer> {
 
 		Object foo(PageRequest request);

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/builder/JdbcCursorItemReaderBuilderTests.java

@@ -46,6 +46,7 @@ import static org.junit.Assert.fail;
 
 /**
  * @author Michael Minella
+ * @author Drummond Dawson
  */
 public class JdbcCursorItemReaderBuilderTests {
 
@@ -156,7 +157,7 @@ public class JdbcCursorItemReaderBuilderTests {
 				.dataSource(this.dataSource)
 				.name("fooReader")
 				.sql("SELECT * FROM FOO WHERE FIRST > ? ORDER BY FIRST")
-				.queryArguments(new Integer[] {3})
+				.queryArguments(3)
 				.rowMapper((rs, rowNum) -> {
 					Foo foo = new Foo();
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/builder/FlatFileItemReaderBuilderTests.java

@@ -46,6 +46,7 @@ import static org.junit.Assert.fail;
 /**
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  */
 public class FlatFileItemReaderBuilderTests {
 
@@ -55,8 +56,8 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(getResource("1  2  3"))
 				.fixedLength()
-				.columns(new Range[] {new Range(1, 3), new Range(4, 6), new Range(7)})
-				.names(new String[] {"first", "second", "third"})
+				.columns(new Range(1, 3), new Range(4, 6), new Range(7))
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -74,7 +75,7 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(getResource("1,2,3"))
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -93,7 +94,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1 2 3"))
 				.delimited()
 				.delimiter(" ")
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -112,7 +113,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1\t2\t3"))
 				.delimited()
 				.delimiter(DelimitedLineTokenizer.DELIMITER_TAB)
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -133,7 +134,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1,2,3\n4,5,$1,2,3$\n@this is a comment\n6,7, 8"))
 				.delimited()
 				.quoteCharacter('$')
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.linesToSkip(1)
 				.skippedLinesCallback(skippedLines::add)
@@ -170,7 +171,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1 2%\n  3\n4 5%\n  6\n@this is a comment\n7 8%\n  9\n"))
 				.fixedLength()
 				.columns(new Range[] {new Range(1, 2), new Range(3, 5), new Range(6)})
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.recordSeparatorPolicy(new DefaultRecordSeparatorPolicy("\"", "%"))
 				.maxItemCount(2)
@@ -202,7 +203,7 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(new FileSystemResource("this/file/does/not/exist"))
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.strict(false)
 				.build();
@@ -250,9 +251,9 @@ public class FlatFileItemReaderBuilderTests {
 		FlatFileItemReader<Foo> reader = new FlatFileItemReaderBuilder<Foo>()
 				.name("fooReader")
 				.resource(getResource("1,2,3\n@this is a comment\n+so is this\n4,5,6"))
-				.comments(new String[] {"@", "+"})
+				.comments("@", "+")
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -276,7 +277,7 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(getResource("1,2,3"))
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.prototypeBeanName("foo")
 				.beanFactory(factory)
 				.build();
@@ -295,7 +296,7 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(getResource("1,2,3"))
 				.delimited()
-				.names(new String[] {"setFirst", "setSecond", "setThird"})
+				.names("setFirst", "setSecond", "setThird")
 				.targetType(Foo.class)
 				.beanMapperStrict(true)
 				.build();
@@ -316,7 +317,7 @@ public class FlatFileItemReaderBuilderTests {
 				.delimited()
 				.includedFields(new Integer[] {0, 2})
 				.addIncludedField(1)
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -383,7 +384,7 @@ public class FlatFileItemReaderBuilderTests {
 					}
 				})
 				.columns(new Range[] {new Range(1, 3), new Range(4, 6), new Range(7)})
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -403,7 +404,7 @@ public class FlatFileItemReaderBuilderTests {
 					.resource(getResource("1  2  3"))
 					.fixedLength()
 					.columns(new Range[]{new Range(1, 3), new Range(4, 6), new Range(7)})
-					.names(new String[]{"first", "second", "third"})
+					.names("first", "second", "third")
 					.targetType(Foo.class)
 					.build();
 			fail("null name should throw exception");
@@ -416,7 +417,7 @@ public class FlatFileItemReaderBuilderTests {
 					.resource(getResource("1  2  3"))
 					.fixedLength()
 					.columns(new Range[]{new Range(1, 3), new Range(4, 6), new Range(7)})
-					.names(new String[]{"first", "second", "third"})
+					.names("first", "second", "third")
 					.targetType(Foo.class)
 					.name(null)
 					.build();
@@ -428,7 +429,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1  2  3"))
 				.fixedLength()
 				.columns(new Range[]{new Range(1, 3), new Range(4, 6), new Range(7)})
-				.names(new String[]{"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.saveState(false)
 				.build());
@@ -437,7 +438,7 @@ public class FlatFileItemReaderBuilderTests {
 				.resource(getResource("1  2  3"))
 				.fixedLength()
 				.columns(new Range[]{new Range(1, 3), new Range(4, 6), new Range(7)})
-				.names(new String[]{"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.name("foobar")
 				.build());
@@ -451,7 +452,7 @@ public class FlatFileItemReaderBuilderTests {
 				.name("fooReader")
 				.resource(getResource("1,2,3"))
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 
@@ -467,7 +468,7 @@ public class FlatFileItemReaderBuilderTests {
 				.encoding(encoding)
 				.fixedLength()
 				.columns(new Range[] {new Range(1, 3), new Range(4, 6), new Range(7)})
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.targetType(Foo.class)
 				.build();
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/builder/FlatFileItemWriterBuilderTests.java

@@ -37,6 +37,7 @@ import static org.junit.Assert.assertTrue;
 /**
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
+ * @author Drummond Dawson
  */
 public class FlatFileItemWriterBuilderTests {
 
@@ -58,10 +59,10 @@ public class FlatFileItemWriterBuilderTests {
 				.resource(output)
 				.delimited()
 				.delimiter(";")
-				.names(new String[] {"foo", "bar"})
+				.names("foo", "bar")
 				.formatted()
 				.format("%2s%2s")
-				.names(new String[] {"foo", "bar"})
+				.names("foo", "bar")
 				.build();
 	}
 
@@ -101,7 +102,7 @@ public class FlatFileItemWriterBuilderTests {
 				.resource(output)
 				.lineSeparator("$")
 				.delimited()
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.encoding("UTF-16LE")
 				.headerCallback(writer1 -> writer1.append("HEADER"))
 				.footerCallback(writer12 -> writer12.append("FOOTER"))
@@ -129,7 +130,7 @@ public class FlatFileItemWriterBuilderTests {
 				.lineSeparator("$")
 				.delimited()
 				.delimiter(";")
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.encoding("UTF-16LE")
 				.headerCallback(writer1 -> writer1.append("HEADER"))
 				.footerCallback(writer12 -> writer12.append("FOOTER"))
@@ -185,7 +186,7 @@ public class FlatFileItemWriterBuilderTests {
 				.lineSeparator("$")
 				.formatted()
 				.format("%2s%2s%2s")
-				.names(new String[] {"first", "second", "third"})
+				.names("first", "second", "third")
 				.encoding("UTF-16LE")
 				.headerCallback(writer1 -> writer1.append("HEADER"))
 				.footerCallback(writer12 -> writer12.append("FOOTER"))

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/support/builder/CompositeItemProcessorBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -34,6 +34,7 @@ import static org.mockito.Mockito.when;
 
 /**
  * @author Glenn Renfro
+ * @author Drummond Dawson
  */
 public class CompositeItemProcessorBuilderTests {
 
@@ -68,10 +69,26 @@ public class CompositeItemProcessorBuilderTests {
 		assertSame(itemAfterSecondTransformation, composite.process(item));
 	}
 
+	@Test
+	public void testTransformVarargs() throws Exception {
+		Object item = new Object();
+		Object itemAfterFirstTransformation = new Object();
+		Object itemAfterSecondTransformation = new Object();
+		CompositeItemProcessor<Object, Object> composite = new CompositeItemProcessorBuilder<>()
+				.delegates(this.processor1, this.processor2).build();
+
+		when(processor1.process(item)).thenReturn(itemAfterFirstTransformation);
+		when(processor2.process(itemAfterFirstTransformation)).thenReturn(itemAfterSecondTransformation);
+
+		assertSame(itemAfterSecondTransformation, composite.process(item));
+	}
+
 	@Test
 	public void testNullOrEmptyDelegates() throws Exception {
 		validateExceptionMessage(new CompositeItemProcessorBuilder<>().delegates(new ArrayList<>()),
 				"The delegates list must have one or more delegates.");
+		validateExceptionMessage(new CompositeItemProcessorBuilder<>().delegates(),
+				"The delegates list must have one or more delegates.");
 		validateExceptionMessage(new CompositeItemProcessorBuilder<>(),
 				"A list of delegates is required.");
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/support/builder/CompositeItemWriterBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@ import static org.mockito.Mockito.verify;
 
 /**
  * @author Glenn Renfro
+ * @author Drummond Dawson
  */
 public class CompositeItemWriterBuilderTests {
 
@@ -58,6 +59,28 @@ public class CompositeItemWriterBuilderTests {
 
 	}
 
+	@Test
+	@SuppressWarnings("unchecked")
+	public void testProcessVarargs() throws Exception {
+
+		List<Object> data = Collections.singletonList(new Object());
+
+		List<ItemWriter<? super Object>> writers = new ArrayList<>();
+
+		ItemWriter<? super Object> writer1 = mock(ItemWriter.class);
+		writers.add(writer1);
+		ItemWriter<? super Object> writer2 = mock(ItemWriter.class);
+		writers.add(writer2);
+
+		CompositeItemWriter<Object> itemWriter = new CompositeItemWriterBuilder<>().delegates(writer1, writer2).build();
+		itemWriter.write(data);
+
+		for (ItemWriter<? super Object> writer : writers) {
+			verify(writer).write(data);
+		}
+
+	}
+
 	@Test
 	public void isStreamOpen() throws Exception {
 		ignoreItemStream(false);