Add ItemWriter for Redis

Issue #3957

pom.xml

@@ -70,6 +70,7 @@
 		<spring-data-commons.version>3.2.0-SNAPSHOT</spring-data-commons.version>
 		<spring-data-jpa.version>3.2.0-SNAPSHOT</spring-data-jpa.version>
 		<spring-data-mongodb.version>4.2.0-SNAPSHOT</spring-data-mongodb.version>
+		<spring-data-redis.version>2.5.2-SNAPSHOT</spring-data-redis.version>
 		<spring-kafka.version>3.0.11-SNAPSHOT</spring-kafka.version>
 		<spring-amqp.version>3.0.9-SNAPSHOT</spring-amqp.version>
 		<spring-ldap.version>3.2.0-SNAPSHOT</spring-ldap.version>

spring-batch-infrastructure/pom.xml

@@ -185,6 +185,12 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-redis</artifactId>
+			<version>${spring-data-redis.version}</version>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.mongodb</groupId>
 			<artifactId>mongodb-driver-sync</artifactId>

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

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2019-2021 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
+ *
+ *      https://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.database;
+
+import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.KeyValueItemWriter;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.util.Assert;
+
+/**
+ * <p>
+ * An {@link ItemWriter} implementation for Redis using a
+ * {@link RedisTemplate} .
+ * </p>
+ *
+ * @author Santiago Molano
+ * @since 4.2
+ */
+public class RedisItemWriter<K, T> extends KeyValueItemWriter<K, T> {
+    private RedisTemplate<K, T> redisTemplate;
+
+
+    @Override
+    protected void writeKeyValue(K key, T value) {
+
+        redisTemplate.opsForValue().set(key, value);
+    }
+
+    @Override
+    protected void init() {
+        Assert.notNull(redisTemplate, "RedisTemplate must not be null");
+    }
+
+    public void setRedisTemplate(RedisTemplate<K, T> redisTemplate) {
+        this.redisTemplate = redisTemplate;
+    }
+}

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

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2019-2021 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
+ *
+ *      https://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.database;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.core.ValueOperations;
+
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+public class RedisItemWriterTests {
+    @Mock
+    private RedisTemplate<String, String> redisTemplate;
+    @Mock
+    private ValueOperations<String, String> valueOperations;
+    private RedisItemWriter<String, String> redisItemWriter = new RedisItemWriter<>();
+    private RedisItemKeyMapper redisItemKeyMapper;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.openMocks(this);
+        redisItemWriter.setRedisTemplate(this.redisTemplate);
+        when(redisTemplate.opsForValue()).thenReturn(valueOperations);
+        doNothing().when(valueOperations).set(any(), any());
+        this.redisItemKeyMapper = new RedisItemKeyMapper();
+        this.redisItemWriter.setItemKeyMapper(redisItemKeyMapper);
+
+    }
+
+    @Test
+    public void shouldWriteToRedisDatabaseUsingKeyValue() {
+        this.redisItemWriter.writeKeyValue("oneKey", "oneValue");
+        verify(this.redisTemplate.opsForValue()).set("oneKey", "oneValue");
+    }
+    @Test
+    public void shouldWriteAllItemsToRedis() throws Exception {
+        List<String> items = Arrays.asList("val1", "val2");
+        this.redisItemWriter.write(items);
+        verify(this.redisTemplate.opsForValue()).set(items.get(0), items.get(0));
+        verify(this.redisTemplate.opsForValue()).set(items.get(1), items.get(1));
+    }
+    static class RedisItemKeyMapper implements Converter<String, String> {
+
+        @Override
+        public String convert(String source) {
+            return source;
+        }
+    }
+}