Added builder for MongoItemWriter

resolves BATCH-2613

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

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2017 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.
+ *  You may obtain a copy of the License at
+ *
+ *          http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.springframework.batch.item.data.builder;
+
+import org.springframework.batch.item.data.MongoItemWriter;
+import org.springframework.data.mongodb.core.MongoOperations;
+import org.springframework.util.Assert;
+
+/**
+ * A builder implementation for the {@link MongoItemWriter}
+ *
+ * @author Glenn Renfro
+ * @since 4.0
+ * @see MongoItemWriter
+ */
+public class MongoItemWriterBuilder<T> {
+
+	private MongoOperations template;
+
+	private String collection;
+
+	private boolean delete = false;
+
+	/**
+	 * Indicates if the items being passed to the writer are to be saved or removed from
+	 * the data store. If set to false (default), the items will be saved. If set to true,
+	 * the items will be removed.
+	 *
+	 * @param delete removal indicator
+	 * @return The current instance of the builder
+	 * @see MongoItemWriter#setDelete(boolean)
+	 */
+	public MongoItemWriterBuilder<T> delete(boolean delete) {
+		this.delete = delete;
+
+		return this;
+	}
+
+	/**
+	 * Set the {@link MongoOperations} to be used to save items to be written.
+	 *
+	 * @param template the template implementation to be used.
+	 * @return The current instance of the builder
+	 * @see MongoItemWriter#setTemplate(MongoOperations)
+	 */
+	public MongoItemWriterBuilder<T> template(MongoOperations template) {
+		this.template = template;
+
+		return this;
+	}
+
+	/**
+	 * Set the name of the Mongo collection to be written to.
+	 *
+	 * @param collection the name of the collection.
+	 * @return The current instance of the builder
+	 * @see MongoItemWriter#setCollection(String)
+	 * 
+	 */
+	public MongoItemWriterBuilder<T> collection(String collection) {
+		this.collection = collection;
+
+		return this;
+	}
+
+	/**
+	 * Validates and builds a {@link MongoItemWriter}.
+	 *
+	 * @return a {@link MongoItemWriter}
+	 */
+	public MongoItemWriter<T> build() {
+		Assert.notNull(this.template, "template is required.");
+
+		MongoItemWriter<T> writer = new MongoItemWriter<>();
+		writer.setTemplate(this.template);
+		writer.setDelete(this.delete);
+		writer.setCollection(this.collection);
+
+		return writer;
+	}
+
+}

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

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2017 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.
+ *  You may obtain a copy of the License at
+ *
+ *          http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.springframework.batch.item.data.builder;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import org.springframework.batch.item.data.MongoItemWriter;
+import org.springframework.data.mongodb.core.MongoOperations;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+/**
+ * @author Glenn Renfro
+ */
+public class MongoItemWriterBuilderTests {
+	@Mock
+	private MongoOperations template;
+
+	private List<String> items;
+
+	@Before
+	public void setUp() throws Exception {
+		MockitoAnnotations.initMocks(this);
+		this.items = new ArrayList<String>() {
+			{
+				add("foo");
+				add("bar");
+			}
+		};
+	}
+
+	@Test
+	public void testBasicWrite() throws Exception {
+		MongoItemWriter<String> writer = new MongoItemWriterBuilder<String>().template(this.template).build();
+		writer.write(this.items);
+
+		verify(this.template).save(this.items.get(0));
+		verify(this.template).save(this.items.get(1));
+		verify(this.template, never()).remove(this.items.get(0));
+		verify(this.template, never()).remove(this.items.get(1));
+	}
+
+	@Test
+	public void testDelete() throws Exception {
+		MongoItemWriter<String> writer = new MongoItemWriterBuilder<String>().template(this.template).delete(true)
+				.build();
+
+		writer.write(this.items);
+
+		verify(this.template).remove(this.items.get(0));
+		verify(this.template).remove(this.items.get(1));
+		verify(this.template, never()).save(this.items.get(0));
+		verify(this.template, never()).save(this.items.get(1));
+	}
+
+	@Test
+	public void testWriteToCollection() throws Exception {
+		MongoItemWriter<String> writer = new MongoItemWriterBuilder<String>().collection("collection")
+				.template(this.template).build();
+
+		writer.write(this.items);
+
+		verify(this.template).save(this.items.get(0), "collection");
+		verify(this.template).save(this.items.get(1), "collection");
+		verify(this.template, never()).remove(this.items.get(0), "collection");
+		verify(this.template, never()).remove(this.items.get(1), "collection");
+	}
+
+	@Test
+	public void testNullTemplate() {
+		try {
+			new MongoItemWriterBuilder<>().build();
+			fail("IllegalArgumentException should have been thrown");
+		}
+		catch (IllegalArgumentException iae) {
+			assertEquals("IllegalArgumentException message did not match the expected result.", "template is required.",
+					iae.getMessage());
+		}
+	}
+}