Add StreamAlternate structure to StreamInfo response

nats-io · scottf · Apr 21, 2025 · Apr 21, 2025 · Apr 21, 2025 · a7d87dc1de862219d46470d9ddc01a95584c8c70
commit a7d87dc1de862219d46470d9ddc01a95584c8c70
diff --git a/src/main/java/io/nats/client/api/StreamAlternate.java b/src/main/java/io/nats/client/api/StreamAlternate.java
@@ -0,0 +1,50 @@
+// Copyright 2025 The NATS 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 io.nats.client.api;
+
+import io.nats.client.support.JsonValue;
+import io.nats.client.support.JsonValueUtils;
+
+import java.util.List;
+
+import static io.nats.client.support.ApiConstants.*;
+import static io.nats.client.support.JsonValueUtils.readString;
+
+public class StreamAlternate {
+    private final String name;
+    private final String domain;
+    private final String cluster;
+
+    static List<StreamAlternate> optionalListOf(JsonValue vSourceInfos) {
+        return JsonValueUtils.optionalListOf(vSourceInfos, StreamAlternate::new);
+    }
+
+    StreamAlternate(JsonValue vLost) {
+        name = readString(vLost, NAME);
+        domain = readString(vLost, DOMAIN);
+        cluster = readString(vLost, CLUSTER);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getDomain() {
+        return domain;
+    }
+
+    public String getCluster() {
+        return cluster;
+    }
+}
diff --git a/src/main/java/io/nats/client/api/StreamInfo.java b/src/main/java/io/nats/client/api/StreamInfo.java
@@ -35,6 +35,7 @@ public class StreamInfo extends ApiResponse<StreamInfo> {
     private final ClusterInfo clusterInfo;
     private final MirrorInfo mirrorInfo;
     private final List<SourceInfo> sourceInfos;
+    private final List<StreamAlternate> alternates;
     private final ZonedDateTime timestamp;
 
     public StreamInfo(Message msg) {
@@ -49,6 +50,7 @@ public StreamInfo(JsonValue vStreamInfo) {
         clusterInfo = ClusterInfo.optionalInstance(readValue(jv, CLUSTER));
         mirrorInfo = MirrorInfo.optionalInstance(readValue(jv, MIRROR));
         sourceInfos = SourceInfo.optionalListOf(readValue(jv, SOURCES));
+        alternates = StreamAlternate.optionalListOf(readValue(jv, ALTERNATES));
         timestamp = readDate(jv, TIMESTAMP);
     }
 
@@ -92,6 +94,10 @@ public StreamConfiguration getConfig() {
         return config;
     }
 
+    public List<StreamAlternate> getAlternates() {
+        return alternates;
+    }
+
     /**
      * Gets the server time the info was gathered
      * @return the server gathered timed

diff --git a/src/main/java/io/nats/client/support/ApiConstants.java b/src/main/java/io/nats/client/support/ApiConstants.java
@@ -23,11 +23,11 @@ public interface ApiConstants {
     String ALLOW_DIRECT      = "allow_direct";
     String ALLOW_MSG_TTL     = "allow_msg_ttl";
     String ALLOW_ROLLUP_HDRS = "allow_rollup_hdrs";
-    String AVERAGE_PROCESSING_TIME = "average_processing_time";
-    String MIRROR_DIRECT     = "mirror_direct";
+    String ALTERNATES        = "alternates";
     String API               = "api";
     String API_URL           = "api_url";
     String AUTH_REQUIRED     = "auth_required";
+    String AVERAGE_PROCESSING_TIME = "average_processing_time";
     String BACKOFF           = "backoff";
     String BATCH             = "batch";
     String BUCKET            = "bucket";
@@ -131,6 +131,7 @@ public interface ApiConstants {
     String METADATA          = "metadata";
     String MTIME             = "mtime";
     String MIRROR            = "mirror";
+    String MIRROR_DIRECT     = "mirror_direct";
     String MSGS              = "msgs";
     String MULTI_LAST        = "multi_last";
     String NAME              = "name";

diff --git a/src/test/java/io/nats/client/api/StreamInfoTests.java b/src/test/java/io/nats/client/api/StreamInfoTests.java
@@ -157,6 +157,10 @@ private void validateStreamInfo(StreamInfo si) {
         validateSourceInfo(si.getSourceInfos().get(0), 17);
         validateSourceInfo(si.getSourceInfos().get(1), 18);
 
+        assertEquals(2, si.getAlternates().size());
+        validateStreamAlternate(si.getAlternates().get(0), 19);
+        validateStreamAlternate(si.getAlternates().get(1), 20);
+
         si = new StreamInfo(JsonValue.EMPTY_MAP);
         assertNull(si.getCreateTime());
         assertNotNull(si.getStreamState());
@@ -180,6 +184,13 @@ private static void validateSourceInfo(SourceInfo sourceInfo, int id) {
         StreamConfigurationTests.validateSubjectTransforms(sourceInfo.getSubjectTransforms(), 2, "" + id);
     }
 
+    private static void validateStreamAlternate(StreamAlternate streamAlternate, int id) {
+        assertNotNull(streamAlternate.toString()); // coverage
+        assertEquals("alt" + id, streamAlternate.getName());
+        assertEquals("domain" + id, streamAlternate.getDomain());
+        assertEquals("cluster" + id, streamAlternate.getCluster());
+    }
+
     private static void validateExternal(External e, int id) {
         assertNotNull(e);
         assertNotNull(e.toString()); // coverage

diff --git a/src/test/resources/data/StreamInfo.json b/src/test/resources/data/StreamInfo.json
@@ -112,5 +112,17 @@
         {"src":"18_st_src1","dest":"18_st_dest1"}
       ]
     }
+  ],
+  "alternates": [
+    {
+      "name": "alt19",
+      "domain": "domain19",
+      "cluster": "cluster19"
+    },
+    {
+      "name": "alt20",
+      "domain": "domain20",
+      "cluster": "cluster20"
+    }
   ]
 }