Fix NPE in ConnectionFactory when nested REQUIRES_NEW transaction establishes no JDBC connections (#764)

* Initial plan

* Fix NPE in ConnectionFactory.notify() when connectionProxyMap is null

Co-authored-by: huayanYu <16700837+huayanYu@users.noreply.github.com>

* Add test for REQUIRED with nested REQUIRES_NEW without JDBC connections

Co-authored-by: huayanYu <16700837+huayanYu@users.noreply.github.com>

* Fix test to avoid duplicate datasource creation

Co-authored-by: huayanYu <16700837+huayanYu@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: huayanYu <16700837+huayanYu@users.noreply.github.com>

Author: Copilot

dynamic-datasource-spring-boot3-starter/src/test/java/com/baomidou/dynamic/datasource/common/v3/DsTransactionalTest.java

@@ -45,6 +45,8 @@ public class DsTransactionalTest {
     private AccountService accountService;
     @Autowired
     private ProductService productService;
+    @Autowired
+    private NonDatabaseConnectionService nonDatabaseConnectionService;
     private DynamicRoutingDataSource ds;
 
     @Test
@@ -84,6 +86,19 @@ public void testDsTransactional() {
         assertThat(productService.selectProduct()).isEqualTo(new Product(1, 10.0, 15));
     }
 
+    @Test
+    public void testRequiredWithRequiresNewNoConnection() {
+        // Setup datasources
+        ds = (DynamicRoutingDataSource) dataSource;
+        if (!ds.getDataSources().containsKey("order")) {
+            DataSourceProperty orderDataSourceProperty = createDataSourceProperty("order");
+            ds.addDataSource(orderDataSourceProperty.getPoolName(), dataSourceCreator.createDataSource(orderDataSourceProperty));
+        }
+        
+        // This should not throw NPE even though the inner REQUIRES_NEW transaction has no JDBC connections
+        nonDatabaseConnectionService.outerRequiredWithConnection();
+    }
+
     private DataSourceProperty createDataSourceProperty(String poolName) {
         DataSourceProperty result = new DataSourceProperty();
         result.setPoolName(poolName);

dynamic-datasource-spring/src/main/java/com/baomidou/dynamic/datasource/tx/ConnectionFactory.java

@@ -109,6 +109,9 @@ public static void notify(String xid, Boolean state) throws Exception {
         boolean hasSavepoint = hasSavepoint(xid);
         List<SavePointHolder> savePointHolders = savePointMap.get(xid);
         Map<String, ConnectionProxy> connectionProxyMap = concurrentHashMap.get(xid);
+        if (connectionProxyMap == null) {
+            return;
+        }
         try {
             //If there is a savepoint,Indicates a nested transaction.
             if (hasSavepoint) {

dynamic-datasource-test-common/src/main/java/com/baomidou/dynamic/datasource/common/service/tx/NoConnectionService.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright © 2018 organization baomidou
+ *
+ * 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 com.baomidou.dynamic.datasource.common.service.tx;
+
+import com.baomidou.dynamic.datasource.annotation.DS;
+import com.baomidou.dynamic.datasource.annotation.DSTransactional;
+import com.baomidou.dynamic.datasource.tx.DsPropagation;
+import org.springframework.stereotype.Service;
+
+/**
+ * Service with REQUIRES_NEW transaction but no JDBC connections
+ */
+@Service
+@DS("order")
+public class NoConnectionService {
+
+    /**
+     * Inner REQUIRES_NEW transaction without JDBC connection
+     * This should not throw NPE when committing
+     */
+    @DSTransactional(propagation = DsPropagation.REQUIRES_NEW)
+    public void innerRequiresNewWithoutConnection() {
+        // No database operations - just business logic
+        System.out.println("Business logic without database operations");
+    }
+}

dynamic-datasource-test-common/src/main/java/com/baomidou/dynamic/datasource/common/service/tx/NonDatabaseConnectionService.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright © 2018 organization baomidou
+ *
+ * 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 com.baomidou.dynamic.datasource.common.service.tx;
+
+import com.baomidou.dynamic.datasource.annotation.DS;
+import com.baomidou.dynamic.datasource.annotation.DSTransactional;
+import com.baomidou.dynamic.datasource.tx.DsPropagation;
+import org.springframework.stereotype.Service;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.Statement;
+
+/**
+ * Test service to reproduce the NPE issue when REQUIRES_NEW has no JDBC connections
+ */
+@Service
+@DS("order")
+public class NonDatabaseConnectionService {
+    private final DataSource dataSource;
+    private final NoConnectionService noConnectionService;
+
+    public NonDatabaseConnectionService(DataSource dataSource, NoConnectionService noConnectionService) {
+        this.dataSource = dataSource;
+        this.noConnectionService = noConnectionService;
+    }
+
+    /**
+     * Outer REQUIRED transaction with JDBC connection
+     */
+    @DSTransactional(propagation = DsPropagation.REQUIRED)
+    public void outerRequiredWithConnection() {
+        // Trigger JDBC connection
+        triggerJdbcConnection();
+        // Call nested REQUIRES_NEW without JDBC connection
+        noConnectionService.innerRequiresNewWithoutConnection();
+    }
+
+    /**
+     * Trigger a JDBC connection
+     */
+    private void triggerJdbcConnection() {
+        try (Connection connection = dataSource.getConnection();
+             Statement statement = connection.createStatement();
+             ResultSet resultSet = statement.executeQuery("SELECT COUNT(*) FROM p_order")) {
+            if (resultSet.next()) {
+                resultSet.getInt(1);
+            }
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}