Parse multiple large communities

src/main/java/org/javamrt/mrt/Attributes.java

@@ -251,15 +251,16 @@ private void decode(byte[] record, int attrLen, int attrBytes)
 
 				case MRTConstants.LARGE_COMMUNITY:
 					if (buffer.length > 0) {
-						Attribute largeCommunity = new LargeCommunity(buffer);
-						attributes.set(MRTConstants.ATTRIBUTE_LARGE_COMMUNITY, largeCommunity);
+						int numberLargeCommunities = len/12; //12 bytes per large community
+						Attribute largeCommunities = new LargeCommunities(buffer, numberLargeCommunities);
+						attributes.set(MRTConstants.ATTRIBUTE_LARGE_COMMUNITIES, largeCommunities);
 					}
 					break;
 
 				default:
 					// make sure to not overwrite other attributes in the Vector,
 					// as index in the Vector is not the same as type value
-					if (type > MRTConstants.ATTRIBUTE_LARGE_COMMUNITY && type < MRTConstants.ATTRIBUTE_TOTAL) {
+					if (type > MRTConstants.ATTRIBUTE_LARGE_COMMUNITIES && type < MRTConstants.ATTRIBUTE_TOTAL) {
 						final UnsupportedAttribute attribute = new UnsupportedAttribute(type, buffer);
 						attributes.set(type, attribute);
 					} else {
@@ -318,9 +319,9 @@ public Community getCommunity() {
 		return Community.empty();
 	}
 
-	public LargeCommunity getLargeCommunity() {
-		return (LargeCommunity)
-                    attributes.elementAt(MRTConstants.ATTRIBUTE_LARGE_COMMUNITY);
+	public LargeCommunities getLargeCommunities() {
+		return (LargeCommunities)
+                    attributes.elementAt(MRTConstants.ATTRIBUTE_LARGE_COMMUNITIES);
 	}
 
 	public Med getMed() {

src/main/java/org/javamrt/mrt/LargeCommunities.java

@@ -0,0 +1,28 @@
+package org.javamrt.mrt;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class LargeCommunities implements Attribute {
+  private List<LargeCommunity> largeCommunities;
+
+  LargeCommunities(byte[] buffer, int numberOfCommunities) {
+    largeCommunities = new ArrayList<>();
+    for (int i = 0; i < numberOfCommunities; i++) {
+      byte[] part = Arrays.copyOfRange(buffer, i * 12, (i + 1) * 12);
+      largeCommunities.add(new LargeCommunity(part));
+    }
+  }
+
+  List<LargeCommunity> getLargeCommunities() {
+    return largeCommunities;
+  }
+
+  @Override
+  public String toString() {
+    return "[" + largeCommunities.stream().map(LargeCommunity::toString)
+        .collect(Collectors.joining(", ")) + "]";
+  }
+}

src/main/java/org/javamrt/mrt/LargeCommunity.java

@@ -8,7 +8,7 @@
 
 import org.javamrt.utils.RecordAccess;
 
-public class LargeCommunity implements Attribute {
+public class LargeCommunity {
     protected long globalAdministrator;
     protected long localData1;
     protected long localData2;

src/main/java/org/javamrt/mrt/MRTConstants.java

@@ -83,7 +83,7 @@ public static String asPathString(int type) {
 	public static final int ATTRIBUTE_AS4_AGGREGATOR = 17;
 	public static final int ATTRIBUTE_CONNECTOR = 20;
 	public static final int ATTRIBUTE_ASPATHLIMIT = 21;
-	public static final int ATTRIBUTE_LARGE_COMMUNITY = 22;
+	public static final int ATTRIBUTE_LARGE_COMMUNITIES = 22;
 	public static final int ATTRIBUTE_TOTAL = 256;
 
 	public static final int AFI_IPv4 = 1;

src/test/java/org/javamrt/mrt/LargeCommunitiesTest.java

@@ -7,13 +7,16 @@
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 import java.util.ArrayList;
-import java.util.Base64;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.Base64;
 import java.util.stream.Collectors;
 
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertNull;
+import static org.testng.Assert.assertTrue;
+
 
 public class LargeCommunitiesTest {
     @Test
@@ -36,10 +39,14 @@ public void testParseDump()
                     Bgp4Update bgp4update = (Bgp4Update) mrtRecord;
                     Attributes attributes = bgp4update.getAttributes();
                     if (attributes != null) {
-                        LargeCommunity largeCommunity =
-                            attributes.getLargeCommunity();
-                        if (largeCommunity != null) {
-                            largeCommunities.add(largeCommunity);
+                        LargeCommunities communities =
+                            attributes.getLargeCommunities();
+                        if (communities != null) {
+                            for (LargeCommunity community : communities.getLargeCommunities()) {
+                                if (community != null) {
+                                    largeCommunities.add(community);
+                                }
+                            }
                         }
                     }
                 }
@@ -73,4 +80,45 @@ public void should_parse_large_community_with_zero_length() throws Exception {
         assertEquals(mrtRecord.getClass(), Advertisement.class);
         assertEquals(mrtRecord.toString(), "BGP4MP|1602194848|A|91.206.52.130|58299|158.247.123.0/24|58299 6939 32261|IGP|91.206.52.130|0|0|58299:1000|NAG||");
     }
+
+    @Test
+    public void should_parse_multiple_large_communities() {
+        Exception exception = null;
+        Set<String> foundCommunities = new HashSet<>();
+        try (InputStream inputStream = getClass().getResourceAsStream("/updates.20260527.2305")) {
+            BGPFileReader bgpFileReader =
+                new BGPFileReader(new BufferedInputStream(inputStream));
+            while (true) {
+                MRTRecord mrtRecord = bgpFileReader.readNext();
+                if (mrtRecord == null) {
+                    break;
+                }
+                if (mrtRecord instanceof Bgp4Update) {
+                    Bgp4Update bgp4update = (Bgp4Update) mrtRecord;
+                    Attributes attributes = bgp4update.getAttributes();
+                    if (attributes != null) {
+                        LargeCommunities largeCommunity = attributes.getLargeCommunities();
+                        if (largeCommunity != null) {
+                            for (LargeCommunity community : largeCommunity.getLargeCommunities()) {
+                                if (community.globalAdministrator == 26162) {
+                                    foundCommunities.add(community.toString());
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception e) {
+            exception = e;
+        }
+        assertNull(exception);
+        assertTrue(foundCommunities.contains("26162:0:65071"), "community not found");
+        assertTrue(foundCommunities.contains("26162:0:266416"), "community not found");
+        assertTrue(foundCommunities.contains("26162:100:2"), "community not found");
+        assertTrue(foundCommunities.contains("26162:200:2"), "community not found");
+        assertTrue(foundCommunities.contains("26162:300:1"), "community not found");
+        assertTrue(foundCommunities.contains("26162:660:1"), "community not found");
+        assertTrue(foundCommunities.contains("26162:670:1"), "community not found");
+        assertTrue(foundCommunities.contains("26162:680:2"), "community not found");
+    }
 }