SOLR-8969: Resolve NPE for SQLHandler when in non-cloud mode

solr/CHANGES.txt

@@ -265,6 +265,8 @@ Other Changes
 
 * SOLR-8385: Narrow StreamFactory.withFunctionName clazz parameter to prevent misconfiguration (Jason Gerlowski, Kevin Risden)
 
+* SOLR-8969: SQLHandler causes NPE in non-cloud mode (Markus Jelsma, Kevin Risden)
+
 ==================  6.2.1 ==================
 
 Bug Fixes

solr/core/src/java/org/apache/solr/handler/SQLHandler.java

@@ -88,6 +88,7 @@ public class SQLHandler extends RequestHandlerBase implements SolrCoreAware , Pe
   }
 
   private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+  static final String sqlNonCloudErrorMsg = "/sql handler only works in Solr Cloud mode";
 
   public void inform(SolrCore core) {
 
@@ -111,7 +112,7 @@ public class SQLHandler extends RequestHandlerBase implements SolrCoreAware , Pe
     String sql = params.get("stmt");
     int numWorkers = params.getInt("numWorkers", 1);
     String workerCollection = params.get("workerCollection", defaultWorkerCollection);
-    String workerZkhost = params.get("workerZkhost",defaultZkhost);
+    String workerZkhost = params.get("workerZkhost", defaultZkhost);
     String mode = params.get("aggregationMode", "map_reduce");
     StreamContext context = new StreamContext();
 
@@ -120,6 +121,10 @@ public class SQLHandler extends RequestHandlerBase implements SolrCoreAware , Pe
 
     try {
 
+      if(workerZkhost == null) {
+        throw new IllegalStateException(sqlNonCloudErrorMsg);
+      }
+
       if(sql == null) {
         throw new Exception("stmt parameter cannot be null");
       }

solr/core/src/test/org/apache/solr/handler/TestSQLHandlerNonCloud.java

@@ -0,0 +1,92 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.solr.handler;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.solr.SolrJettyTestBase;
+import org.apache.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.stream.SolrStream;
+import org.apache.solr.client.solrj.io.stream.TupleStream;
+import org.apache.solr.common.params.CommonParams;
+import org.apache.solr.common.params.ModifiableSolrParams;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.common.util.IOUtils;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class TestSQLHandlerNonCloud extends SolrJettyTestBase {
+
+  private static File createSolrHome() throws Exception {
+    File workDir = createTempDir().toFile();
+    setupJettyTestHome(workDir, DEFAULT_TEST_COLLECTION_NAME);
+    return workDir;
+  }
+
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    File solrHome = createSolrHome();
+    solrHome.deleteOnExit();
+    createJetty(solrHome.getAbsolutePath());
+  }
+
+  @Test
+  public void testSQLHandler() throws Exception {
+    String sql = "select id, field_i, str_s from " + DEFAULT_TEST_COLLECTION_NAME + " limit 10";
+    SolrParams sParams = mapParams(CommonParams.QT, "/sql", "stmt", sql);
+    String url = jetty.getBaseUrl() + "/" + DEFAULT_TEST_COLLECTION_NAME;
+
+    SolrStream solrStream = new SolrStream(url, sParams);
+    try {
+      getTuples(solrStream);
+      fail(SQLHandler.sqlNonCloudErrorMsg);
+    } catch (IOException e) {
+      assertTrue(e.getMessage().contains(SQLHandler.sqlNonCloudErrorMsg));
+    }
+  }
+
+  private List<Tuple> getTuples(TupleStream tupleStream) throws IOException {
+    List<Tuple> tuples = new ArrayList<>();
+    try {
+      tupleStream.open();
+      for (; ; ) {
+        Tuple t = tupleStream.read();
+        if (t.EOF) {
+          break;
+        } else {
+          tuples.add(t);
+        }
+      }
+    } finally {
+      IOUtils.closeQuietly(tupleStream);
+    }
+    return tuples;
+  }
+
+  public static SolrParams mapParams(String... vals) {
+    ModifiableSolrParams params = new ModifiableSolrParams();
+    assertEquals("Parameters passed in here must be in pairs!", 0, (vals.length % 2));
+    for (int idx = 0; idx < vals.length; idx += 2) {
+      params.add(vals[idx], vals[idx + 1]);
+    }
+
+    return params;
+  }
+}