#2389 - redis.clients.jedis.exceptions.JedisDataException: ERR wrong number of arguments for 'mget' command

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorCacheHelp.java

@@ -349,12 +349,13 @@ final class BeanDescriptorCacheHelp<T> {
     for (Object id : ids) {
       keys.add(desc.cacheKey(id));
     }
-
+    if (ids.isEmpty()) {
+      return new BeanCacheResult<>();
+    }
     Map<Object, Object> beanDataMap = beanCache.getAll(keys);
     if (beanLog.isTraceEnabled()) {
       beanLog.trace("   MGET {}({}) - hits:{}", cacheName, ids, beanDataMap.keySet());
     }
-
     BeanCacheResult<T> result = new BeanCacheResult<>();
     for (Map.Entry<Object, Object> entry : beanDataMap.entrySet()) {
       CachedBeanData cachedBeanData = (CachedBeanData) entry.getValue();

ebean-redis/src/main/java/io/ebean/redis/RedisCache.java

@@ -117,6 +117,9 @@ final class RedisCache implements ServerCache {
 
   @Override
   public Map<Object, Object> getAll(Set<Object> keys) {
+    if (keys.isEmpty()) {
+      return Collections.emptyMap();
+    }
     long start = System.nanoTime();
     Map<Object, Object> map = new LinkedHashMap<>();
     List<Object> keyList = new ArrayList<>(keys);

ebean-redis/src/test/java/org/integration/IntegrationTest.java

@@ -11,6 +11,7 @@ import org.junit.jupiter.api.Test;
 
 import java.time.LocalDate;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -18,6 +19,22 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 class IntegrationTest {
 
+  @Test
+  void mget_when_emptyCollectionOfIds() {
+
+    List<RCust> f0 = new QRCust()
+      .setIdIn(Collections.emptyList())
+      .findList();
+
+    assertThat(f0).isEmpty();
+
+    List<RCust> f1 = new QRCust()
+      .id.in(Collections.emptyList())
+      .findList();
+
+    assertThat(f1).isEmpty();
+  }
+
   @Test
   void mput_via_setIdIn() throws InterruptedException {
 
@@ -187,8 +204,8 @@ class IntegrationTest {
 
   private List<Person> nameStartsWith(String pattern) {
     return new QPerson()
-        .name.istartsWith(pattern)
+      .name.istartsWith(pattern)
-        .setUseQueryCache(true)
+      .setUseQueryCache(true)
-        .findList();
+      .findList();
   }
 }