Apache Solr support: implement DELETE collection

langstream-agents/langstream-vector-agents/src/main/java/ai/langstream/agents/vector/solr/SolrAssetsManagerProvider.java

@@ -63,15 +63,9 @@ public void initialize(AssetDefinition assetDefinition) throws Exception {
 
         @Override
         public boolean assetExists() throws Exception {
-            String collectionName = getCollectionName();
-            log.info("Handling SOLR collection {}", collectionName);
             return describeCollection();
         }
 
-        private String getCollectionName() {
-            return datasource.getClientConfig().getCollectionName();
-        }
-
         @Override
         public void deployAsset() throws Exception {
             List<Map<String, Object>> statements =
@@ -84,20 +78,16 @@ public void deployAsset() throws Exception {
         }
 
         private boolean describeCollection() throws IOException, InterruptedException {
-            String schemaUrl = datasource.getCollectionUrl() + "/schema";
-            HttpResponse<String> get =
-                    httpClient.send(
-                            HttpRequest.newBuilder().uri(URI.create(schemaUrl)).GET().build(),
-                            HttpResponse.BodyHandlers.ofString());
-            String currentSchema = get.body();
-            log.info("Describe collection {}", getCollectionName());
-            log.info("Result: {}", currentSchema);
-            if (get.statusCode() == 404) {
+            String collectionUrl = datasource.getRESTCollectionUrl();
+            String result = execute("GET", collectionUrl);
+            if (result == null) { // this should have been 404, but actually Solr 9.3 returns 400
+                log.info("Collection {} does not exist", datasource.getCollectionName());
                 return false;
             }
-            if (get.statusCode() != 200) {
-                throw new IOException("Error while querying collection schema: " + get.body());
-            }
+            String schemaUrl = datasource.getCollectionUrl() + "/schema";
+            String currentSchema = execute("GET", schemaUrl);
+            log.info("Describe collection {}", datasource.getCollectionName());
+            log.info("Result: {}", currentSchema);
             return true;
         }
 
@@ -140,7 +130,39 @@ private void execStatements(List<Map<String, Object>> statements) throws Excepti
 
         @Override
         public boolean deleteAssetIfExists() throws Exception {
-            return false;
+            boolean exists = describeCollection();
+            if (!exists) {
+                return false;
+            }
+            String collectionUrl = datasource.getRESTCollectionUrl();
+            ;
+            log.info("Deleting collection {}", datasource.getCollectionName());
+            execute("DELETE", collectionUrl);
+            return true;
+        }
+
+        private String execute(String method, String url) throws IOException, InterruptedException {
+            HttpResponse<String> response =
+                    httpClient.send(
+                            HttpRequest.newBuilder()
+                                    .uri(URI.create(url))
+                                    .method(method, HttpRequest.BodyPublishers.noBody())
+                                    .build(),
+                            HttpResponse.BodyHandlers.ofString());
+            log.info("{} {}: Status code {}", method, url, response.statusCode());
+            if (response.statusCode()
+                            == 400 // this should have been 404, but actually Solr 9.3 returns 400
+                    || response.statusCode() == 404) {
+                return null;
+            }
+            if (response.statusCode() != 200) {
+                throw new IOException(
+                        "Error while calling url "
+                                + url
+                                + ", http status code is "
+                                + response.statusCode());
+            }
+            return response.body();
         }
 
         @Override

langstream-agents/langstream-vector-agents/src/main/java/ai/langstream/agents/vector/solr/SolrDataSource.java

@@ -21,6 +21,8 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -148,5 +150,15 @@ public void close() {
                 client.close();
             }
         }
+
+        public String getRESTCollectionUrl() {
+            return getBaseUrl()
+                    + "/api/collections/"
+                    + URLEncoder.encode(getCollectionName(), StandardCharsets.UTF_8);
+        }
+
+        public String getCollectionName() {
+            return getClientConfig().getCollectionName();
+        }
     }
 }

langstream-agents/langstream-vector-agents/src/test/java/ai/langstream/agents/vector/datasource/impl/SolrWriterTest.java

@@ -264,7 +264,9 @@ void testWrite() throws Exception {
                 assertEquals(0, results3.size());
 
                 assertTrue(tableManager.assetExists());
-                tableManager.deleteAssetIfExists();
+                assertTrue(tableManager.deleteAssetIfExists());
+                assertFalse(tableManager.assetExists());
+                assertFalse(tableManager.deleteAssetIfExists());
             }
         }
     }