Store group info in json

src/main/java/cli/JsonGroupStore.java

@@ -0,0 +1,50 @@
+package cli;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class JsonGroupStore {
+    @JsonProperty("groups")
+    @JsonSerialize(using = JsonGroupStore.MapToListSerializer.class)
+    @JsonDeserialize(using = JsonGroupStore.GroupsDeserializer.class)
+    private Map<String, GroupInfo> groups = new HashMap<>();
+
+    private static final ObjectMapper jsonProcessot = new ObjectMapper();
+
+    void updateGroup(GroupInfo group) {
+        groups.put(Base64.encodeBytes(group.groupId), group);
+    }
+
+    GroupInfo getGroup(byte[] groupId) {
+        return groups.get(Base64.encodeBytes(groupId));
+    }
+
+    public static class MapToListSerializer extends JsonSerializer<Map<?, ?>> {
+        @Override
+        public void serialize(final Map<?, ?> value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException {
+            jgen.writeObject(value.values());
+        }
+    }
+
+    public static class GroupsDeserializer extends JsonDeserializer<Map<String, GroupInfo>> {
+        @Override
+        public Map<String, GroupInfo> deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
+            Map<String, GroupInfo> groups = new HashMap<>();
+            JsonNode node = jsonParser.getCodec().readTree(jsonParser);
+            for (JsonNode n : node) {
+                GroupInfo g = jsonProcessot.treeToValue(n, GroupInfo.class);
+                groups.put(Base64.encodeBytes(g.groupId), g);
+            }
+
+            return groups;
+        }
+    }
+}