From fb2e29b39730821e1983dfc6df9f8c78642fc9f4 Mon Sep 17 00:00:00 2001
From: Chen Li <717626659@qq.com>
Date: Thu, 17 Feb 2022 13:57:31 +0800
Subject: [PATCH 1/3] Support for scan in RedisTemplate.

---
 .../data/redis/core/RedisOperations.java        | 12 +++++++++++-
 .../data/redis/core/RedisTemplate.java          | 16 +++++++++++++++-
 .../core/RedisTemplateIntegrationTests.java     | 17 +++++++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/springframework/data/redis/core/RedisOperations.java b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
index d4404435d7..67fb405577 100644
--- a/src/main/java/org/springframework/data/redis/core/RedisOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2021 the original author or authors.
+ * Copyright 2011-2022 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.
@@ -45,6 +45,7 @@
  * @author Mark Paluch
  * @author ihaohong
  * @author Todd Merrill
+ * @author Chen Li
  */
 public interface RedisOperations<K, V> {
 
@@ -259,6 +260,15 @@ <T> T execute(RedisScript<T> script, RedisSerializer<?> argsSerializer, RedisSer
 	@Nullable
 	Set<K> keys(K pattern);
 
+	/**
+	 * Use a {@link Cursor} to iterate over keys.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @see <a href="https://redis.io/commands/scan">Redis Documentation: SCAN</a>
+	 */
+	Cursor<K> scan(ScanOptions options);
+
 	/**
 	 * Return a random key from the keyspace.
 	 *
diff --git a/src/main/java/org/springframework/data/redis/core/RedisTemplate.java b/src/main/java/org/springframework/data/redis/core/RedisTemplate.java
index 9075f96933..d67295496a 100644
--- a/src/main/java/org/springframework/data/redis/core/RedisTemplate.java
+++ b/src/main/java/org/springframework/data/redis/core/RedisTemplate.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2021 the original author or authors.
+ * Copyright 2011-2022 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.
@@ -83,6 +83,7 @@
  * @author Mark Paluch
  * @author Denis Zavedeev
  * @author ihaohong
+ * @author Chen Li
  * @param <K> the Redis key type against which the template works (usually a String)
  * @param <V> the Redis value type against which the template works
  * @see StringRedisTemplate
@@ -897,6 +898,19 @@ public Set<K> keys(K pattern) {
 		return keySerializer != null ? SerializationUtils.deserialize(rawKeys, keySerializer) : (Set<K>) rawKeys;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.RedisOperations#scan(java.lang.Object)
+	 */
+	@Override
+	public Cursor<K> scan(ScanOptions options) {
+		Assert.notNull(options, "ScanOptions must not be null!");
+
+		return executeWithStickyConnection(
+				(RedisCallback<Cursor<K>>) connection -> new ConvertingCursor<>(connection.scan(options),
+						this::deserializeKey));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.RedisOperations#persist(java.lang.Object)
diff --git a/src/test/java/org/springframework/data/redis/core/RedisTemplateIntegrationTests.java b/src/test/java/org/springframework/data/redis/core/RedisTemplateIntegrationTests.java
index caaecbb800..8f470920d3 100644
--- a/src/test/java/org/springframework/data/redis/core/RedisTemplateIntegrationTests.java
+++ b/src/test/java/org/springframework/data/redis/core/RedisTemplateIntegrationTests.java
@@ -62,6 +62,7 @@
  * @author Mark Paluch
  * @author ihaohong
  * @author Hendrik Duerkop
+ * @author Chen Li
  */
 @MethodSource("testParams")
 public class RedisTemplateIntegrationTests<K, V> {
@@ -126,6 +127,22 @@ void testKeys() throws Exception {
 		assertThat(redisTemplate.keys(keyPattern)).isNotNull();
 	}
 
+	@ParameterizedRedisTest // GH-2260
+	void testScan() {
+		K key1 = keyFactory.instance();
+		V value1 = valueFactory.instance();
+		assumeThat(key1 instanceof String || key1 instanceof byte[]).isTrue();
+		redisTemplate.opsForValue().set(key1, value1);
+		Cursor<K> cursor = redisTemplate.scan(ScanOptions.scanOptions().count(1).build());
+		long count = 0;
+		while (cursor.hasNext()) {
+			assertThat(cursor.next()).isEqualTo(key1);
+			count++;
+		}
+		cursor.close();
+		assertThat(count).isEqualTo(1);
+	}
+
 	@SuppressWarnings("rawtypes")
 	@ParameterizedRedisTest
 	void testTemplateNotInitialized() throws Exception {

From 9a8c032693fbdae357631b471ac7217981ce8c8b Mon Sep 17 00:00:00 2001
From: Chen Li <717626659@qq.com>
Date: Thu, 17 Feb 2022 14:36:55 +0800
Subject: [PATCH 2/3] Add notification for scan.

---
 .../org/springframework/data/redis/core/RedisOperations.java     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/main/java/org/springframework/data/redis/core/RedisOperations.java b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
index 67fb405577..6420746ca1 100644
--- a/src/main/java/org/springframework/data/redis/core/RedisOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
@@ -262,6 +262,7 @@ <T> T execute(RedisScript<T> script, RedisSerializer<?> argsSerializer, RedisSer
 
 	/**
 	 * Use a {@link Cursor} to iterate over keys.
+	 * <strong>Important:</strong> Call {@link Cursor#close()} when done to avoid resource leak.
 	 *
 	 * @param options must not be {@literal null}.
 	 * @return never {@literal null}.

From b0c7b11fae0deac872df8da2d87508d71f375f7e Mon Sep 17 00:00:00 2001
From: Chen Li <717626659@qq.com>
Date: Thu, 17 Feb 2022 14:44:01 +0800
Subject: [PATCH 3/3] New line for notification.

---
 .../org/springframework/data/redis/core/RedisOperations.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/org/springframework/data/redis/core/RedisOperations.java b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
index 6420746ca1..e9a153b569 100644
--- a/src/main/java/org/springframework/data/redis/core/RedisOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/RedisOperations.java
@@ -261,7 +261,7 @@ <T> T execute(RedisScript<T> script, RedisSerializer<?> argsSerializer, RedisSer
 	Set<K> keys(K pattern);
 
 	/**
-	 * Use a {@link Cursor} to iterate over keys.
+	 * Use a {@link Cursor} to iterate over keys. <br />
 	 * <strong>Important:</strong> Call {@link Cursor#close()} when done to avoid resource leak.
 	 *
 	 * @param options must not be {@literal null}.